Guideline on Landslide Treatment and...

Department of Soil Conservation and Watershed ManagementKathmandu, June 2016

(Asar 2073)

Guideline on Landslide Treatment and Mitigation

Department of Soil Conservation and Watershed ManagementG.P.O. BOX 4719, Babar Mahal, Kathmandu, NepalT: 977-1-4220828/4220857 | F: 977-1-4221067

E: [email protected]/[email protected]: www.dscwm.gov.np


Department of Soil Conservation and Watershed Management

Kathmandu, June 2016

(Asar 2073)

| Guideline on Landslide Treatment and Mitigationii

PublisherDepartment of Soil Conservation and Watershed Management,

Ministry of Forests and Soil Conservation,

Babar Mahal, Kathmandu, Nepal

Cover photo credit

Landslide in Rasuwa©Mr. Jagannath Joshi

Credits

© Department of soil Conservation and Watershed Management (DSCWM)

Kathmandu, Nepal

Landslide Treatment and Mitigation Sub-GroupCoordinator: Mr. KesharMan Sthapit (FAO Nepal Office)

Members:

Mr. GehendraKeshariUpadhyaya (DSCWM)

Dr. Jagannath Joshi (DSCWM)

Mr. Deepak Bhardwaj (DSCWM)

Mr. Shanmukhesh Chandra Amatya (Department of Water Induced Disaster Management)

Ms. Laxmi Thagunna (Department of Environment)

Ms. Racchya Shah (IUCN Nepal)

Mr. Bhawani Shankar Dongol (WWF Nepal)

Mr. Sanjay Devkota (Forum for Energy and Environment Development)

Mr. Deo Raj Gurung (ICIMOD)

Advisor: Mr. Purna Chandra Lal Rajbhandari (UNEP)

Citation

DSCWM (2016), Guideline on Landslide Treatment and Mitigation.Department of soil Conservation and Watershed

Management, Kathmandu, Nepal.

We are very thankful to USAID funded Hariyo Ban Program, WWF Nepal for providing support to edit,

format and print this guideline.

Guideline on Landslide Treatment and Mitigation | iii

| Guideline on Landslide Treatment and Mitigationiv

Guideline on Landslide Treatment and Mitigation | v

Preface

The working group on “Landslide Treatment and Mitigation” was established following the recommendations of the

consultative workshop on “Landslide Inventory, Risk Assessment, and Mitigation” organized by the Department of Soil

Conservation and Watershed Management (DSCWM) from 28-29 September 2015 at Kathmandu. FAO, ICIMOD, IUCN, UNDP,

UNEP, and WWF collaborated in the workshop. The first Coordination Meeting of Partner Organizations held on 14 October

2015 established the working group that Food and Agriculture Organization-Nepal will coordinate.

FAO designated Mr. Keshar Man Sthapit (Former DG of DSCWM) as coordinator. The members include Mr. Gehendra Keshari

Upadhyaya, Dr. Jagannath Joshi, and Mr. Deepak Bhardwaj, DSCWM; Mr. Shanmukhesh Chandra Amatya, Department of

Water Induced Disaster Management; Ms. Laxmi Thagunna, Department of Environment; Ms. Racchya Shah, IUCN Nepal; Mr.

Bhawani Shankar Dongol, WWF Nepal; Mr. Sanjay Devkota, Forum for Energy and Environment Development (FEED); and Mr.

Deo Raj Gurung, ICIMOD. Mr. Purna Chandra Lal Rajbhandari from UNEP was assigned as advisor.

The “Landslide Treatment and Mitigation” working group held its first meeting on December 18, 2015 and second meeting

on January 29, 2016.

The working group prepared this Guideline through a desk review of pertinent literature, guidelines, and relevant

documents on nationally and internationally adopted practices, and through extensive consultation workshops and

meetings with experts and practitioners. Eventually, it finalized the guideline after incorporating comments and suggestions

made by various experts and District Soil Conservation Officers at a national level validation workshop on June 19, 2016.

The terms of reference of the working group are in Annex 1. This Working Group 3 (Landslide treatment and

mitigation) produced this report describing the guideline, including assessment of landslides for urgency of treatment,

recommendations for treatment, landslide mapping, different techniques used, and basic surveying required for designing

techniques. The report also provides a training schedule for building the capacity of field professionals and a format for

documentation of the lessons learned.

The coordinator appreciates the valuable contributions of the members of the working group.

Keshar Man Sthapit

Coordinator

Landslide Treatment and Mitigation Sub-Group

Guideline on Landslide Treatment and Mitigation | vii

Acronyms and Abbreviations

DG Director General

DSCO District Soil Conservation Office

DSCWM Department of Soil Conservation and Watershed Management

FAO Food and Agriculture Organization of the United Nations

FEED Forum for Energy and Environment Development

GoN Government of Nepal

GPS Global Positioning System

Ha Hectare

MRE Mountain Risk Engineering

NARMSAP Natural Resource Management Sector Assistance Programme

ICIMOD International Centre for Integrated Mountain Development

ILO International Labour Organisation

IUCN International Union for Conservation of Nature

UNDP United Nations Development Program

UNEP United Nations Environment Program

VDC Village Development Committee

WWF World Wildlife Fund

Guideline on Landslide Treatment and Mitigation | ix

Table of Contents

Foreword iii

Preface v

Acronyms and Abbreviations vii

1. Background and Objectives of Landslide Treatment 1

1.1. Main Objectives of Landslide Treatment 1

1.2. Scope of Landslide Treatment 1

2. Urgency and Recommendation for Treatment 3

2.1. Assessment of Urgency and Recommendation 4

3. Landslide Mapping and Surveying to Identify Key Problems 7

3.1. Detailed Mapping of Landslides 7

3.2. Landslide Survey 8

3.3. Problem Identification 9

4. Treatment and Mitigation Measures for Landslides 11

4.1. Landslide Treatment Techniques 11

4.2. Treatments for Specific Zones of the Landslide 11

4.2.1. Upstream and Side Periphery Zones of the Landslide 11

4.2.2. Downstream Zone of Landslide 12

4.2.3. Catchment Area 13

4.2.4. Main Landslide 13

4.3. Practical Considerations and Approaches 14

4.3.1. Landslide Treatment Approach and Working Season 14

5. Capacity Building and Lesson Learned Documentation 15

6. References 17

| Guideline on Landslide Treatment and Mitigationx

viii

List of Tables

List of Annexes

Table 1. Definition of Common Terms 3

Table 2. Treatability Status 4

Table 3. Evaluation Matrix for Assessment of Urgency for Treatment Existing Landslide 5

Table 4. Assessment of Recommendation for Treatment 6

Annex 1. Terms of Reference: Sub-group 3. Landslide Treatment and Mitigation 19

Annex 2. Mapping Steps (Modified after NARMSAP/DSCWM, 2004 and 2005) 21

Annex 3. Basic Surveying 24

Annex 4. Landslide Treatment Techniques 26

Annex 5. List of Commonly Used Species 67

Annex 6. Proposed Training Module for Capacity Building in Landslide Treatment 69

Annex 7. Landslide Inventory 71

Annex 8. Format for Documentation of the Lessons Learned 74

Guideline on Landslide Treatment and Mitigation | 1

Landslide is a general term describing a mass of material

that has slipped downhill under the influence of gravity.

In mountainous terrain, such as Nepal, landslides happen

relatively frequently, especially when the soil is saturated

with water1 as during the heavy monsoon rains.

Landslides cause damage to lives and settlements,

development infrastructures, agricultural fields, and

forests. They occur because of complex forces in

conjunction with the slope morphology, hydrology, and

geotechnical parameters of the material. They occur

when the shear stress exceeds the shear strength of the

material. Other terms to refer to landslide events include

‘mass movements’, ‘slope failures’, ‘slope instability’, and

‘terrain instability’.

The causes of landslides and the problems they create

in the hazard areas determine the types of landslide

treatment and mitigation. Generally, landslide treatment

focuses on the immediately affected areas to fix the sliding

and reduce immediate adverse impacts on the surrounding

area. Mitigation focuses on minimizing the longer-term

occurrence of landslides in a whole watershed.

For example: Immediate or short term measures

includes drainage management, slope stabilization with

engineering structures, such as retaining or toe walls, or

riprap, to address the immediate effects of a landslide.

Medium and long-term measures cover a whole watershed

to improve cultivation practices, and better manage crops,

water, pasture, and watershed vegetation cover through

afforestation.

Therefore, landslide treatment is done every year to

protect property and lives in Nepal. Landslide treatment

refers to the vegetative and structural measures applied

in the landslide area and its influential catchment that

aim to reduce soil erosion and mass movement from

landslide and reduce the devastating effects on the areas

downstream and surrounding the landslide.

1.1. Main Objectives of Landslide Teatment are to: • prevent further movement of slopes by controlling

runoff and erosion

• prevent damage upslope and down slope

• improve water quality and management

• stabilize the landslide area for productive purposes.

1.2. Scope of Landslide TreatmentLandslide treatment stabilizes the landslide and reduces

the adverse impacts upstream and downstream of the

landslide. These activities include managing land and

water resources upstream of the landslide and periphery

area, stabilizing the slope within the landslide, protecting

and improving land use downstream of the landslide, and

protecting the area. It includes bioengineering techniques

to reduce erosion, and water management activities to

dispose water safely and reduce moisture in the landslide

area.

Landslide treatment measures can be categorized into

three general measures:

• proper land husbandry through land use improvement

practices,

• managing water through proper drainage

management and maintaining appropriate soil

moisture, and

• strengthening slope stability through bio engineering

techniques.

1Chapter

Background and Objectives of Landslide Treatment

1 Soil Conservation Society of America-1982, Resource Conservation Glossary Third edition.

2 DSCWM 1992, Soil Conservation and Watershed Management Activities (Definition, Objective, Scope and Working Strategy). Department

of Soil Conservation and Watershed Management, Kathmandu, Nepal.

| Guideline on Landslide Treatment and Mitigation2

Stream bank stabilization by fascine. © Keshar Man Sthapit


2Chapter

Urgency and Recommendation for Treatment

An analysis of a landslide, in terms of the urgency to

treat them and recommendations for their treatment, is

essential to better use the resources available. Table 1

gives definitions to create a common understanding of

landslides and the hazards involved.

Table 1. Definition of Common Terms

Landslide hazard3

Probability of a landslide event happening at a certain magnitude, described by:

• Triggering mechanism

• Type of landslide event

• Magnitude of landslide event

Triggering mechanisms are generally categorized as:

• Toe cutting, steep slope

• Lack of water management, heavy rain, steep slope

• Cracked rocks, steep slope, earthquake

Types of landslides

Most common types of landslides in Nepal and their consequent phenomena are:

• Rock fall: Abrupt movements of rocks that free fall or roll or bounce

• Debris slides: Down slope movement (sliding) of debris caused by shear failure (rotational)

on a distinct surface or by sliding shallow debris without a distinct slip surface (translational).

• Debris flow: Rapid down slope movement by vicious fluid debris without a slip surfaces.

• Sedimentation: Deposition of fine sediment washed down by the landslide.

Landslide vulnerability

Degree of damage or loss resulting from the landslide event, a function of:

• Magnitude of event, and

• Types of elements at risk

Element at risk is categorized as:

• Settlements and lives

• Development infrastructure

• Agriculture

• Forests, shrubs or grasslands

Risk

Expected degree of losses to the element at risk, because of a landslide event within a given

area and time.

Risk is a product of the combination of a landslide event, vulnerability, and quantification

(degree) of damage to the elements at risk.

Quantification (degree) of damage to the element at risk may be categorized as high,

moderate, or low.

3 Presentation on “Landslide Risk Assessment” by Xuanmei Fan, Runqiu Huang, and Cees Van Western. May 25, 2016. State Key

Laboratory of Geo-hazards Prevention and Geo-environment Protection, Changdu University of Technology.

Of the two concepts, URGENCY, relates to the level

of risk to human assets or natural resources, and

RECOMMENDATION refers to the feasibility of treating a

landslide.


Urgency of treatment

Urgency of treatment is based on:

• type of landslide event and consequent phenomena,

such as rock fall, sliding debris, debris flow, or

sedimentation

• probability of another landslide occurrence, whether

high, moderate, or low

• elements at risk, such as settlements, development

infrastructure, agriculture or forests, and shrub or

grasslands

• degree of losses (high, moderate or low) to the

element at risk from the landslide event.

Recommendation for treatment

Once the urgency of treatment is determined, it is

important to know whether to recommend the landslide

for treatment.

Recommendation for treatment is based on:

• element at risk and urgency for treatment due to

potential damage to settlements, development

infrastructure, or to agriculture, forests, shrub, or

grassland

• major factor triggering or enlarging the landslide,

such as toe cutting on a steep slope; lack of water

management on a steep slope after heavy rain; or

cracked rocks on a steep slope after an earthquake.

The steepness of the slope is a triggering factor.

• treatability status of the landslide -- the feasibility of

how easily the landslide can be treated based on the

criteria in Table 2.

2.1. Assessment of Urgency and Recommendation Steps to assess the urgency of treatment

1. Determine which type of landslide event is prevalent

and the probability of its occurrence.

2. Determine the elements at risk and/or damage

caused to settlements, development infrastructure,

agriculture land, or forests, shrub, and grassland

3. Assess the degree (quantify) of damage to the

element at risk whether high, moderate, or low.

4. Decide the urgency of treatment of the existing

landslide by matching the above information in the

corresponding rows and columns of the evaluation

matrix in Table 3 below.

Steps to determine the recommendation for treatment:

1. Determine the element at risk and potential damage

2. Assess the treatability status using Table 2 below

3. Assess the major factors triggering or enlarging

the landslide, such as toe cutting, lack of water

management and heavy rain, or cracked rocks due to

earthquakes

4. Based on the urgency for treatment from Table 3,

decide upon the recommendation for treatment of the

landslide using the matrix in Table 4.

Table 2. Treatability Status

Treatability Status Criteria

Easily Easily treatable with bioengineering measures within two years.

It includes shallow seated landslides on moderate slopes, less than 60%

Moderately Moderately treatable with some engineering structures and bioengineering measures within five

years

It includes shallow seated landslides on steep slopes, more than 60%

Difficultly Difficultly treatable with large engineering structures and longer than five years

It includes deep-seated landslides on steep slopes, more than 60%

Note Shallow seated: Movement of earth mass down to the C horizons (Soil’s Parent materials). This type of landslide is treatable using bioengineering techniques with reasonable resources and time, when landslides affect settlements and livelihoods (agriculture, forests, and grazing land). No bedrock is disturbed or moved.

Deep seated: Movement resulted in cracks in the bedrock and bedrock movement. Treatment of such landslides requires large structures, with reinforced concrete and grouting, using vast resources, and needing a long time. These landslides are treated when they affect infrastructure of high economic value, such as highways, hydropower, and large settlements.

Remarks: When the recommendation for treatment is low or very low, that is, treatment of the landslide is not recommended, it does not mean that the situation does not require any action. If the analysis shows that the urgency of treating the landslide is very high, high, or moderate, the recommended action may be the relocation of the settlement or infrastructures, or realignment of the road or irrigation canal. The urgency of the treatment determines the level of relocation or realignment.


Tabl

e 3.

Eva

luat

ion

Mat

rix f

or A

sses

smen

t of

Urg

ency

of

Trea

tmen

t Ex

istin

g La

ndsl

ide

Haz

ard

Type

Elem

ent

at r

isk

Type

of

land

slid

e

even

t an

d

cons

eque

nt

phen

omen

a

Prob

abili

ty

(Cha

nces

)

of

occu

rren

ce

Sett

lem

ent

and

lives

Dev

elop

men

t in

fras

truc

ture

sA

gric

ultu

reFo

rest

s/Sh

rub

/G

rass

land

s

Qua

ntifi

catio

n (D

egre

e) o

f da

mag

e to

the

ele

men

t at

ris

k

HM

LH

ML

HM

LH

ML

Rock

fal

lH

igh

V. H

igh

V. H

igh

Mod

erat

eV.

Hig

hH

igh

Mod

erat

eM

oder

ate

Low

Low

Mod

erat

eLo

wV.

Low

Mod

erat

eH

igh

Hig

hM

oder

ate

Hig

hM

oder

ate

Low

Low

V. L

owV.

Low

Low

V. L

owV.

Low

Low

Hig

hM

oder

ate

Low

Mod

erat

eLo

wV.

Low

Low

V. L

owV.

Low

V. L

owV.

Low

V. L

ow

Slid

ing

/

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ris fl

ow

Hig

hV.

Hig

hV.

Hig

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Hig

hH

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Mod

erat

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Mod

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wM

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Low

V. L

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wV.

Low

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Sedi

men

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Low

Low

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Mod

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Mod

erat

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Low

Hig

hM

oder

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V. L

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Low

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Low

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Low

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Low

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Sym

bol:

H: H

igh,

M: M

oder

ate,

L: L

ow,

V. H

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Ver

y H

igh,

V. L

ow: V

ery

Low


Tabl

e 4.

Ass

essm

ent

of R

ecom

men

dati

on f

or T

reat

men

t

Elem

ent

at r

isk

Trea

tabi

lity

stat

usM

ajor

fac

tors

tri

gger

ing

/ E

nlar

ging

land

slid

e

Toe

cutt

ing,

Ste

ep s

lope

Lack

of

wat

er m

anag

emen

t, H

eavy

rai

n, S

teep

slo

peCr

acke

d ro

cks,

Ste

ep s

lope

, Ear

thqu

ake

Urg

ency

for

tre

atm

ent

V. H

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Mod

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wV.

L.

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lyV.

S.R.

V.S.

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ttle

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ttle

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res

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lyV.

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R.V.

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Mod

erat

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R.M

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omm

ende

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ent

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cult

lyS.

R. /

Real

ignm

ent

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. /

Real

ignm

ent

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Real

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ent

N.R

./ R

ealig

nmen

tS.

R. /

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ent

M.R

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ent

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ent

N.R

./ R

ealig

nmen

tM

.R. /

Real

ignm

ent

M.R

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Real

ignm

ent

R/

Real

ignm

ent

Agr

icul

ture

Easi

ly

Not

Rel

evan

t

S.R.

M.R

.R

Not

Rel

evan

t

S.R.

M.R

.R

Not

Rel

evan

t

RN

ot R

ecom

men

ded

Mod

erat

ely

M.R

.M

.R.

RM

.R.

M.R

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Not

Rec

omm

ende

d /

Land

use

cha

nge

Diffi

cult

lyR

/ La

nd u

se

chan

ge

N.R

.N

.R.

R /

Land

use

chan

ge

N.R

. / L

and

use

chan

ge

Fore

sts,

Gra

ss la

nd a

nd

Rock

y ar

ea

Easi

ly

Not

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evan

t

S.R.

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Not

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t

S.R.

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t

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omm

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cult

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.N

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.N

.R.

N.R

.

V. H

. = V

ery

Hig

hM

od. =

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erat

eV.

L. =

Ver

y Lo

w

V.S.

R. =

Ver

y st

rong

ly r

ecom

men

ded

S.R.

= S

tron

gly

reco

mm

ende

dM

.R. =

Mod

erat

ely

reco

mm

ende

d

R =

Reco

mm

ende

d /

Land

use

cha

nge

to P

erm

anen

t ve

geta

tion

N.R

. = N

ot r

ecom

men

ded/

Lan

d us

e ch

ange

to

Perm

anen

t ve

geta

tion

Sym

bol:


3Chapter

Landslide Mapping and Surveying to Identify Key Problems

Designing landslide treatment and mitigation measures

requires field investigations to identify the different

features and the key problems of the landslides.

Information from the landslide inventory and landslide

mapping are the basis for further field investigation of the

different zones of the landslide. See Annex 2 for landslide

mapping tips.

When investigating a landslide, it is divided into zones:

4 Main landslide at the center

4 Upstream zone: Upstream of the main landslide area

where probable cracks developed.

4 Side periphery: Land on either side of main landslide,

which may slide if cracks developed or the surface

deformed.

4 Downstream zone:

Fans: Area at the outlet at the lower end of the

landslide, where course debris deposited.

Sedimentation zone: Further down from the fan,

where fine and medium size particles washed down

and deposited.

3.1. Detailed Mapping of Landslides Mapping of upstream and side periphery zones of

the landslide: Generally, this zone includes crack zones

and the catch area. Crack zones are usually close to the

scarp of the landslide and very sensitive, demanding

urgent treatment. In this zone, it is essential to seal

cracks, manage drainage, and ensure proper land use for

erosion control. Crack zones are more prominent above

the landslide head than in the periphery. Mapping of the

catch area needs to show the different land uses requiring

different treatments; gullies demanding treatment; water

sources such as springs, irrigation canals, ponds, and

drainage channels; and settlements showing houses.

Mapping downstream of the landslide: While further mapping

the downstream zone of the landslide, map the fan where

course debris from the landslide has deposited and show the

main flow path. Any element in the fan area will be at risk.

Mapping of the sedimentation zone: Further, down on the

fan of debris deposition, is the area with medium and fine

sediment deposition. As the slope lessens, there is further

deposition of washed out soil materials. Map the area

affected by medium and fine sediment deposition showing

the different land uses and infrastructure, including the

houses. Sediment deposition may have adverse effects on

crops and settlements. The degree of the damage depends

on the quantity of sediment, its size, and runoff.

Mapping of the main landslide: Landslides have four

zones -- the crack zone, failure zone, transport zone, and

depositional zone (fan and sedimentation zone). When

mapping a landslide, show the following features on the

map.

4 Hanging rock and earth mass: Falling rock or earth

may endanger life and property down slope. It is

essential to knock off hanging rock or earth masses to

avoid this threat.

4 Cracks or hollow: Any crack within the landslide

indicates that the ground is under tension and still

subject to slope failure. While mapping cracks and


hollows, assess the width and depth of the cracks.

Wide, deep cracks or hollows show a possible serious

slope failure.

4 Scarps or cliff: Scarp slopes and cliffs are common in a

landslide close to the rim of the landslide and within

the landslide where localized slips happened.

4 Benches and terraces: Map where rotational slides

created benches or terraces within the landslide area.

Benches are usually below the scarp / cliff and show

the previous land use.

4 Irregular surface: Map any irregular or undulating

surface area where water may accumulate and help

to trigger more landslides.

4 Water features: Map water features such as springs,

potholes, and spring lines, to show water movement

within the landslide. Darker colored soil and plants

(especially water loving plants) point out dampness

and moisture. Whether a spring is perennial

or seasonal needs to be marked on the map.

Depressions or hollows with accumulated water in the

landslide show the seriousness of the slope failure

and slumping.

4 Drainage line: Map all drainage lines including rills

and gullies and show the portion of the drainage or

gully requiring treatment. Assess the total length of

the rills and the length, width, and slope of the gullies

and drainage requiring treatment.

4 Rock outcrop: Show any rock outcrop within the

landslide because rock outcrops help to assess the

rock type, soil depth, and depth of the slide.

4 Colluvial slope: Indicate where any colluvial deposits

are within the landslide and assess their average

slope and stone size.

4 Barren slope: Show any barren slope requiring re-

vegetation.

4 Toe of the slope: The ‘toe’ supports every slope

and toe protection is essential to stabilize the

slope. Identify the toe line of the slope so it can be

protected from cutting, erosion, sliding, and moisture

saturation. The indicator of the toe of the slope is any

change in the angle of the slope, mostly from steep

to less steep.

4 Path: Sometimes landslide encompasses the path,

although it might be disturbed by the sliding.

Generally, path line is more stable than other sloping

part within the landslide .

3.2. Landslide SurveyApart from the landslide mapping, some measurements in

the field are required to specify the distance, profile, plan,

and cross section. How to measure the distance, plan,

profile, and cross section is given in Annex 3.

Although best measured in the field, distance and plan can

be measured using Google Earth. If the plan is prepared

in Google Earth, the area for different treatments to be

applied can be estimated using http://www.earthpoint.us.

Plan

Cross Section


For structural measurements (diversion canals, check

dams, or retaining walls), it is most appropriate to do

field measurements using measuring tapes and surveying

equipment, such as clinometers, clino-compass, level,

theodolite, Global Positioning System (GPS), etc.

3.3. Problem IdentificationMeasures to treat and mitigate landslides need to analyze

the cause triggering the problem. All earth material has

an angle of repose. However, when the slope angle of

an earth mass becomes greater than angle of repose, the

slope fails and the material moves downslope.

The angle of repose changes depending upon underlying

materials, moisture conditions, and conservation status.

With time, weathering changes the underlying material

from rock to soil, with rain, the moisture increases, and

with different human activities, the conservation status

changes. Therefore, with changes, the slope has to change

to be in a stable position again.

A slope that is stable today may not be stable tomorrow

as factors affecting its angle of repose change. For slope

stabilization, it is necessary to understand the dynamics of

these factors in the slope to design and apply conservation

measures appropriately.

Key problems

Some key problems causing slope failure include:

} Slope cutting

l To construct infrastructure, people cut the slope

increasing the angle of the slope to be greater

than its angle of repose. As a result, the slope

fails and earth slips downslope.

l Rivers and streams erode their banks at the toe of

the slope increasing its angle to be greater than

the angle of repose. Consequently, the slope fails.

} Over saturation

l Rain adds the water to the slope, saturating the

earth mass and decreasing the cohesion of slope

materials. The result can be a slope failure.

l Pore water pressure in the slope increases with

the addition of moisture, which can create

downward pressures causing slope failure.

l Mismanagement of drainage: In the process of

building infrastructure -- roads, irrigation, ponds

and reservoirs, etc. -- the natural drainage may

not tolerate adding more water or moisture in

certain places, resulting in slope failure.

} Excess weight

l The construction of infrastructure, such as

buildings, roads, heavy retaining walls, etc. may

add weight beyond what the slope can support,

resulting in slope failure.

l Growth of big trees on the slope can add weight

that eventually triggers slope failure.

l Addition of water in the earth mass adds weight,

resulting in slope failure.

Stabilization of landslide by wattling.© Keshar Man Sthapit


4Chapter

Treatment and Mitigation Measures for Landslides

Various different measures for landslide treatment

depend on the features identified or mapped that are

causing problems. The following are specific techniques

for addressing various problems in landslides and general

recommendations for treating the various zones of

landslides.

4.1. Landslide Treatment Techniques4 Different techniques can address the various problems in

the landslides. Measures and techniques appropriate for

addressing different problems of the landslide treatment

are as follows:

a) Land use improvement: Techniques include

conservation plantation, grass plantation, on-farm

conservation, agro-forestry, safe water drainage, and

runoff harvesting ponds or dams in the catchment.

b) Drainage management: To prevent runoff from

flowing into landslides and to drain the excess water

from landslides, drainage management is essential.

Drainage management may be surface and sub-

surface drainage management.

l Surface drainage management: Techniques

applied include construction of diversion

waterways, sealing of tension cracks so that

rainwater cannot get inside and build up pore-

water pressure, rip-rap (stone or vegetative or

combined) of the waterways. These techniques

are appropriate for controlling shallow slides.

l Sub-surface drainage management: Techniques

applied include sub-surface drainage trenches

filled with gravel, perforated drainage pipes

(vertical and horizontal), which are appropriate

for reducing pore-water pressure along failure

planes.

l Conservation ponds to store and divert excess

run-off.

c) Surface erosion control: Techniques applied include

grass or tree sapling planting, jute netting, mulching,

wattling, and brush layering

d) Erosion control in rills: Techniques applied include

fascine, contour grass planting, rip-rap, and palisade

(wide rills).

e) Erosion control in gullies: Techniques applied include

palisade (small gullies), and check dams made of

brushwood, stone, boulders, gabions, masonry, or

concrete.

f) Slope failure due to slope cutting or steep slope:

Techniques applied include crib walls of bamboo, poles,

or concrete), retaining or toe walls of stone, gabion,

masonry, or concrete. Anchoring may be used in a deep-

seated landslide to bolt the rock bed but this is not easy

and is generally not used unless the landslide affects

national structure, such as hydropower or a highway.

g) Slope failure due to heavy load on slope upstream

of landslide: Techniques applied include excavation to

remove rock and soil from the head of a landslide to

reduce the driving force, and filling rock at the toe of

the landslide to increase resistance against movement.

h) Slope failure due to toe cutting by stream / river:

Techniques applied include revetment, spurs, or a rip-

rap toe wall to prevent cutting by the stream or river.

i) Protection of the landslide area from biotic

interference: Generally used soil conservation

techniques in landslide treatment are described in

Annex 4. Different species are used in the applying

conservation techniques. List of local names and their

botanical names and vice versa of commonly used

species are given in Annex 5.

4.2. Treatments for Specific Zones of the LandslideThe following are specific techniques and measure for

treating the various zones of landslides.

4.2.1. Upstream and Side Periphery Zones of the Landslide

This includes the crack zone above the landslide and the

catch area.

4 DSCWM 2004, Soil Conservation and Watershed Management Measures and Low Cost Techniques. Soil Conservation and Watershed

Management Component (SCWMC), Natural Resource Management Sector Assistance Programme (NARMSAP), Department of Soil

Conservation and Watershed Management (DSCWM), Babar Mahal.


Crack zoneCrack sealing: Runoff water entering cracks saturates

the land mass, reducing its cohesion as the pore water

pressure increases and makes the slope more subject to

failure. The runoff water entering the land mass through

cracks is more serious than surface runoff. Therefore, a

prime treatment in the crack zone is sealing cracks with

any available material, but preferably clay soil.

Water management: Diverting surface runoff from

the crack area close to the landslide is very tricky and

sensitive. A crack area is prone to movement when it

becomes wet, so construction of a diversion channel

may create more hazard than good if cracks develop in

the channel and the diverted water enters the landslide

through the cracks. Any depression where water

accumulates in a crack zone needs to be filled or reshaped

to drain surface runoff and stabilize the slope.

Load management: In the crack zone, any heavy load may

lead slope failure. It could be advantageous to remove

any heavy structure, such as a house, retaining wall, or big

trees. In the crack zone, it is best to grow grass, shrubs,

and bushes.

Cultivation in the crack zone close to the rim of the

landslide should not be allowed. However, when the crack

zone has expanded well above the rim of the landslide, it

is difficult to prevent people from cultivating crops there.

To avoid adverse impacts in such cases, it is important

to promote safe disposal of runoff, improved cultivation,

crop management, proper pasture management, and

afforestation on the barren and degraded slope.

Rills and gullies need to be treated with bioengineering

techniques, such as fascines, palisades, brush layering,

brushwood check dams, wattling, loose stone check dams,

vegetative rip-rap, and grass planting.

4.2.2. Downstream Zone of Landslide

Downstream Zones of landslides have two main parts.

The fan of course debris at the base of the landslide and

the sedimentation area further down with medium to fine

sediment flow.

Fan (of course debris): Below the main landside, course

debris will have deposited in the fan. Any mass movement

in the landslide will endanger everything in this area so

it is a high-risk zone. Generally, a stream or river will be

flowing at the end of the fan. If the stream or river is

cutting the toe of the fan, the primary treatment will be

protecting the toe of the fan.

Contour bunding with large stones (preferably boulders)

and leveling of the land behind the bunding (in another

word, terracing) could be an appropriate treatment. Where

there is a debris flow, contour bunding will dissipate the

energy of the debris flow to avoid damage downstream.

It is also beneficial to do contour planting of grass, shrubs,

and trees so that the vegetation will reduce the movement

of the sediment flow downstream through the fan.

Toe protection: If a stream is eroding the toe of the fan,

it is important to construct a protection wall to stop the

stream from eroding the end of the fan. This will help

stabilize the fan and the slope above it in the landslide.

To help protect the fan from erosion, other structures may

need to be constructed such as retaining walls, toe walls,

embankments, and spurs.

Protect fan from cutting or erosion: Terrace building and

vegetation growth in the fan will protect it from erosion

and reduce any further movement of debris. In cases

where a road passes through the fan of a landslide, the

removal of materials falling onto the road is almost like

toe cutting the fan slope, which makes the fan unstable.

Roads at top of debris fan: It would be most appropriate

to run the road at the top of the debris deposition in the

fan rather than clearing the debris to cut through the

middle of the fan. This increases the road slope, but the

increase in the depth of deposition in the fan supports

the upslope of the landslide. If the landslide is active, any

treatment in this area may be subject to damage. If there

is a prominent channel in the fan, it is best to maintain the

channel, so that water and sediment flow are confined to

the channel, reducing damage to the fan.

Sedimentation zone (Deposition zone of medium and

fine sediment): Generally, a landslide will carry medium

and fine sediment further down from a fan to deposit it on

the gentle slope area below. A sedimentation zone is more

prominent if there is no stream or river flowing at the end

of the fan. If there is a stream or river originated from

other catch area flowing at the end of the fan, it will be

difficult to delineate the sedimentation area clearly.

Treatment measures: The conservation measures to

protect the area and treat the landslide will be to trap

sediment in the fan, establish a buffer strip across the

sedimentation area, and safely channelize the flow from

the fan into a major river. The most appropriate treatment

would be channelization of the flow with a protection

wall, revetment, and spurs, and rehabilitation of reclaimed

land by planting of grass, shrubs and trees, and on-farm

improvement behind the protection wall. Rehabilitate

agricultural land by removing the debris (rocks, stones,


pebbles, gravel, etc.), digging and bringing the buried soil

to spread on top, and adding good sediments (silt, clay,

organic matter) from outside the area.

4.2.3. Catchment Area

Land use improvement: The catchment area above the

crack zone generally requires proper land use and safe

disposal of runoff water. Conservation techniques to apply

in the catchment area include plantation of trees and

grass, on-farm conservation, and a safe drainage network.

Therefore, the catchment area needs to be mapped

specifying different land uses that demand different

treatments; gullies demanding treatment; water sources

such as springs, irrigation canals, ponds, and drainage

channels; and settlements showing houses.

Improved cultivation includes planting of trees and grass

on waste areas between the farmlands, protecting from

raiser failure by planting grass or building stonewalls,

leveling of sloping agricultural land, and improving the

drainage network in the farmland.

Crop management includes changing from crops requiring

too much moisture to crops requiring less moisture. For

example, changing from wetland paddy to the system

of rice intensification (SRI), wheat, millet, or maize, and

changing from seasonal cereal crops to more perennial

crops, such as fruit trees or agro-forestry orchards.

Rills and gullies need treatment with bioengineering

techniques such as fascines, palisades, brush layering,

brushwood check dams, wattling, loose stone check dams,

vegetative rip-rap, and grass planting.

Drainage management: The safe disposal of water from

the catchment area that enters the landslide plays a key

role in landslide treatment. The key measures to divert

water from entering to the landslide are construction of a

drainage network and a diversion canal in the catchment

area to divert water away from the landslide area. A

conservation pond and a series of water holding trenches

could help manage water in the catchment area so long as

they are not close to the landslide.

Practical considerations for drainage and waterways improvement

} Always design drainage systems to run along natural

drainage lines

} Never use contour drains because they can block very

easily and are susceptible to subsidence. A blocked or

cracked drain can create terrible damage because of

concentrated water flow in the landslide.

} Design and construct drains in such a way that water

can enter easily from the higher side into the canal

but not seep out of the canal from the lower side.

} Diversion waterways must be well above the

crack zones. Waterways must be wide enough to

accommodate the maximum runoff and be earthen or

lined, depending on the site condition.

} Precautions must be taken to dispose the diverted

runoff safely in the stable natural drainage system so

that no new gully or landslide is created.

} Regular cleaning of drainage and prevention of

leakage in the diversion channel is essential for safe

disposal of water.

4.2.4. Main Landslide

Treatment of the main landslide depends on its different

features and the most feasible treatment for each feature.

However, it is important to note that suggested treatments

must not be adapted blindly without considering the

overall situation of the landslide. This is also not an

exhaustive list of suggested treatments.

Hanging rocks and earth mass: Knock down all possible

hanging rocks and earth mass as a first step. This will avoid

the risk to life and property from falling rock and earth

masses.

Cracks and hollows: Seal all cracks as soon as possible to

prevent runoff water from entering into the earth mass,

which results in greater risk of mass movement.

Scarp and cliff: Stability of the scarp slope depends on

the composition of the material. If the scarp slope seems

stable, keep it as it is. If the scarp slope is not stable,

reshape it to 35 to 45º. Hold the debris from reshaping the

scarp slope by constructing a contour bund or wall at the

foot of the scarp slope. One concern is if the heavy load

of a bund or wall will enlarge the landslide. Stabilize the

reshaped slope using wattling, vegetative riprap, brush

layering, grass seeding, or planting grass slips and tree

saplings.

Benches and terraces: Do not disturb a bench unless

there is a depression holding water. If so, the fill the

depression with debris and plant the surface with grass

and bush. Construction of conservation structures such as

contour bunding and catch wall in the benches could be

considered if appropriate.

Irregular surfaces: Irregular or undulating surface areas need

to be smoothed so that no water is accumulates on them.

Water features: Springs, potholes (depressions including

ponds), and seepage lines are major water features in a


landslide other than the drainage line. Water management

is the key activity in landslide treatment.

} Spring: Collect water from the spring and drain it

through the drainage network as soon as possible.

Draining spring water through inclined perforated

pipes under the surface may help in the management

of spring water.

} Pothole: Fill potholes (depressions) holding water.

} Seepage line: The seepage line is the weakest part

of the landslide and shows the toe line for the slope

above. It is essential to construct a toe wall to drain

water from the seepage line. It may help to drain

the water from the seepage line through inclined

perforated pipes under the surface.

} Drainage line: The safe disposal of runoff water

is a key activity in landslide treatment. Some

recommended activities for drainage protection are

vegetative stone pitching of the drainage line and

construction of a series of low height check dams.

If the drainage slope is steep, a structure with step

drops is appropriate for the safe disposal of runoff. In

an area with big runoff, a cement or concrete lined

channel or drop structures may be required.

Colluvial slope: Stabilize the colluvial slope with contour

bunding, contour leveling with appropriate spacing, and

growing vegetation.

Barren slope: Protect barren slopes from surface erosion

by diagonal grass planting, jute netting/mulching, and

planting seedlings and cuttings. Stabilize slopes with

retaining walls, contour bolsters, contour stone bunding,

bush layering, wattling, and vegetative riprap.

The moisture concentration in a slope can be managed

by laying stone filled sub-surface drainage in a with

herringbone pattern. Rills and gullies in the barren slopes

can be treated with bioengineering techniques, such as

fascines, palisade, brush layering, brushwood check dams,

wattling, loose stone check dams, vegetative rip-rap, and

grass planting.

Toe of the slope: Each slope has its own toe usually seen

where the slope changes from steep to less steep. Protect

the toe by constructing a toe wall, vegetative pitching the

toe area, and draining moisture from the toe line.

Path: Improvement of the path will help the activities

carried out for landslide treatment.

4.3. Practical Considerations5 and Approaches Landslide treatment is a complex activity because each

landslide is different from all others. Different site-specific

techniques are based on the problem analysis. Landslide

treatment has the most successful results when the

recommended techniques are implemented as a package.

This package may be expensive so if the resources are not

available to implement all the recommended techniques as a

package, it is advisable to implement the activities in phases.

It may also be necessary to implement the techniques over

several years, rather than as a one-time activity. The landslide

situation may also change over time, so the techniques and

measures may need to be changed. Therefore, landslide

treatment needs to be viewed as a dynamic process.

Expensive structures should not be used to treat geological

(natural) landslides unless and until they affect habitation

or infrastructure (e.g. roads and hydropower projects).

4.3.1. Landslide Treatment Approach and Working Season

Community involvement is integral to successful landslide

treatment, which should include with the protection of

settlements including educational centres, initiatives to

reinstate livelihoods, water resource infrastructures such as

irrigation and drinking water source, and agriculture land.

} Any time when workers are available or during

farmers’ slack season for structural works. However,

the rainy season is risky for the construction of

structures.

} During the dry dormant season if the site is moist.

Vegetative work should be done just before the

monsoon for the best results.





5Chapter

Capacity Building and Lesson Learned Documentation

Several government organizations and NGOs are working

with the Department of Soil Conservation and Watershed

Management on landslide treatment and mitigation

activities. After the earthquake of April 25, 2015, the need

for landslide treatment has increased greatly in Nepal. The

need is enormous compared to the monetary and human

resources available. There is a serious lack of technical

skills in landslide treatment and mitigation among the

available human resources. Therefore, it is essential to

build the capacity of field professionals in survey, design,

and implementation of the landslide treatment and

mitigation activities.

Annex 6 gives a proposed training module and schedule

for capacity building on landslide treatment. Annex 7 gives

a proposed format for the documentation of lesson learned

from the implementation of the landslide treatment

activities. Landslide treatment measures are site specific so

there is a need for continuous upgrading of technologies,

knowledge, and skill in landslide treatment and mitigation.


Broom grass plantation to stabilize slope.© Keshar Man Sthapit


6Chapter

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Website for the presentation in the Consultative

Workshop Landslide Inventory, Risk Assessment

and Mitigation in Nepal: http://www.icimod.org/

landslideworkshop2015


Annexes

Annex 1. Terms of Reference: Sub-group 3. Landslide Treatment and Mitigation

} Recommend the best approach for the execution of

the landslide treatment and mitigation to Nepalese

context.

Scope of work:

} Collect and review all the related documents,

information, guidelines, methodologies, initiatives,

and tools on the landslide treatment and mitigation

measures.

} In line with the workshop’s resolution, the sub-group

should prepare methodology / guidelines considering

the following points:

o Local: It should directly involve the local

communities with the possibility of maximum

use of local materials.

o Simple and easy to use: the method should be

relatively simple having not complex design

consideration, structural parts.

o Guidelines should stress complete treatment of

the landslide using bio engineering techniques

(integration of vegetative techniques with small

scale engineering structure) suitable to the

ecosystem. The sub-group should list the best

suitable species and their characteristics to be

used in the context of Nepal.

} Prepare guidelines with clear methodology for survey,

design, estimation, and costing of landslide treatment

and mitigation measures.

} The sub-group should work on the software part

(training) about the information of landslide risk, its

prevention and safer activities to avoid landslides.

} DSCWM, DSCO will be helping on the field testing,

assessment of the structural components.

Methodology:

This working group has liberty to use varieties of widely

accepted and scientific methods and tools to accomplish

the given task. Team should first assess the different

6 Testing of the methodology and documentation of the lesson learned in the implementation will be responsibility of the implementing

organizations. However, the sub group will prepare format for documentation so that the leaning could be used to update the guideline.

Background:

The consultative workshop recognized the need for close

coupling of treatment work with inventory and hazard

zonation. This should facilitate categorization of landslides

that require mitigation. This should come from the national

landslide inventory and local hazard assessment. It was

felt that priorities should be given both at the community

level as well as for large infrastructures. A strong coupling

of mechanical, biological, and ecosystem based strategies

is suggested. The landslide stabilization should focus on

reinforcing livelihood and food security based on the available

ecosystem services. A formal coordination agency to take

the lead role with operational support from public, private,

civil society and community is also pointed out. Community

participation, Proper land use planning, Establishment of an

early warning system at the local level, Awareness raising,

Capacity building are considered as enabling elements and be

integrated as part of the total project cycle.

Objective of the assignment:

The broader objective of this task is to come up with

methodology (sequential steps) to be followed in applying

landslide treatment and mitigation measures that will be

most appropriate to Nepalese context and can be uniformly

used by different agencies and experts as per their needs.

The specific objectives are:

} Explore and evaluate the methodologies and tools

used for landslide treatment and mitigation in Nepal

and other countries.

} Based on experience and available document

recommend guidelines (sequential steps) for

pragmatic methods in applying landslide treatment

and mitigation measures.6

} Recommend the required survey, design and practical

considerations/ materials required / format for

estimation and conditions to use the methods and

guidelines.


guidelines/methods used on the subject matter and keep

themselves informed of the relevant studies and workouts

available regarding the job.

Supervision and coordination:

The Sub-group will closely work with and report to the

main working group and/ or liaison person assigned.

Overall technical advice will be provided by the

consortium of the partner organizations or DSCWM and

S.No. Deliverables

1 Field assessment guideline for landslide treatment and mitigation

2 Survey, design, and implementation guidelines for different techniques to be applied in the landslide treatment

and mitigation.

3 List of reference materials

4 Training framework to enable the practitioners to apply the guideline and techniques.

5 Framework for documentation of lesson learned of the different techniques.

other related agencies as per decision of the partners’

meeting.

Deliverables:

Electronic copies of tools and methodology of landslide

treatment and mitigation should be submitted to

the coordinator of the working group in report form.

Particularly, the sub-group should produce and support for

the following deliverables.


Annex 2. Mapping Steps (Modified after NARMSAP/DSCWM, 20047 and 20058)

Steps in a suggested procedure Draw, Measure or describe

Step 1 Prepare map of about 1:1000 – 5000 scale (Depending upon the size to the

landslide)

Draw, describe, measure

If it is not possible to prepare such a map, make a sketch map (sketch the site

from a good observation point most preferably in A4 size paper) or use Google

image (wherever possible):

Observe and record physical condition

• Note the exact location of landslide so that other people can easily locate

the site with the help of the note if necessary,

• Mark landslide boundary

• Indicate the presence of an old landslide if any,

• Indicate the features like road, streams, springs, canal (irrigation canals or

drainage structures), that may either have caused it in the first place, or they

may be contributing to future failure.

• Indicate catchment area including major land use types requiring treatment,

• Indicate houses, roads, or other structures in close proximity

• Landmarks on the site, such as prominent trees, etc.

Step 2 Geomorphic situation Draw, describe

Look at the general locality and situation of the site:

• Record in which part of the slope the landslide has originated from i.e.

upper part (upper concave part) of the slope, middle part or lower part

(convex) of the slope.

• Note if it is in a part of the landscape where instability would be expected

Step 3 Landslide zoning Draw

• Mark

• Crack zone outside the main landslide area (look and mark cracked area

on the top and around sides of the landslide)

• Scarp zone

• Transportation zone

• Deposition zone i.e. fan and sedimentation zone

Step 4 Mapping of main landslide

• Indicate hanging rock or earth mass to be knocked down before

implementing any conservation measures

• Indicate main scarp mostly found around the rim of the landslide

• Indicate individual scarp and measure its slope and length and width

• Mark any less steep benches and measure the length, width, and slope

• Mark and measure any back tilted slope, where water may collect

• Mark path passing through the landslide

• Mark any rock outcrop




8 DSCWM, 2005. Training handout on Bioengineering and Survey, Design and Estimation of Soil Conservation Activities- SCWMC, NARMSAP,

DSCWM, Kathmandu, Nepal.



Step 5 Mark and measure the surface water body and drainage Draw

• Mark and measure surface drainage pathways (springs, canals) that may

require diverting away from the landslide

• Mark and measure drainage network (stream, rills and gullies) that may

require conservation measures for safe disposal or protection

• Mark and measure any seepage line, spring, swamp, pot holes that may

need to be drained

• Irrigation canals or drainage structures, especially masonry drainage

ditches.

Step 6 Mapping of depositional zone

• Map the fan

• Mark the boundary of the fan

• Indicate the drainage lines in the fan

• Assess the materials types (Alluvium, Colluvium)

• Measure the average slope, dimension (Length and width) and stone size

• Assess broadly the wetness category (Moist, Wet or Dry)

• Map the sedimentation zone

• Assess the material type (Fine, medium or course)

• Measure the average slope and dimension of sedimentation zone

• Indicate the land use type

Step 7 Slope material examinations (Slope forming material and debris) Draw, describe

• Colluvial slope: Slope of material moved downhill mainly by gravitational

force and deposited lower on the slope. The materials are angular

fragments and alluvial in parts. Assess the average slope, dimension, and

stone size in the colluvial deposition.

• Barren slopes: Any slope in the landslide devoid of vegetation. Assess the

average slope and dimensions.

• Assess the wetness of the slopes (Moist, wet and dry).

Step 8 Rock: Look the bed rock surface wherever exposed Draw

• Note the uniformity or layering (bedding) of the rock units:

• Mark alternating hard and soft rocks if any

• Assess hardness of the rocks (weathering): Soft and Hard rock

• Note degree of fracturing of rock, especially any open fracture

• Note the orientation of the rock fracture

• Note any signs of water movement along fractures

Step 9 Prepare profile and cross section Draw, measure

• Sketch a slope profile of the landslide from top to bottom.

• Measure the slope of different zones and places where treatment is

required

• If slope measurement is not possible, make an ocular estimate. Angles may

not be actual, but should indicate relative steepness.

• Survey the longitudinal profile and cross section of the landslide area,

where the check dams, retaining wall and toe wall, etc. that need to be

installed.



Step 10 Record history and life progression of landslide Describe, draw

Step 11 Identify causes and mechanisms of landslide Describe, draw

• Mark problems of toe cutting

Step 12 Assess and design landslide treatment activities Describe

Remarks:} Trees leaning in different directions often indicate a

slow creep of surface materials down slope without

imminent slope failure.

} Fresh debris indicates a landslide upslope.

} Most landslides enlarge with time. Generally, the area

studied should be 2 – 3 times wider and longer than

the landslide area.

} Analyze geology, topography, drainage, and other

natural and man-made elements to understand the

processes of the landslide to design optimal measures

to treat the landslide.


Annex 3. Basic Surveying

1. Introduction to surveying

Surveying is the art of making measurements (of the

relative positions) of natural and man-made features on

the earth’s surface for presentation either graphically

or digitally. Basically surveying consists of linear

measurement of horizontal distances, bearings indicating

direction of the measurement with north, and elevation

of the measured points corresponding to sea level as a

reference. Basics of surveying are as follows:

a. Linear measurement

Linear measurement is measuring the distance between

two points and expressed in the horizontal distance. If the

measurement is carried out in the slope the measured

distance in the slope need to be converted into horizontal

distance.

Benchmark is a surveyor’s mark on a permanent object

of predetermined position and elevation used as a

reference point. In surveying with bearing and distance

measurements, objects and points are located with respect

to bench marks in a horizontal plane.

Fore and back bearing

The bearing of a line differs accordingly whether the

observation is made from one end of the line or from

the other. If the bearing of a line AB is measured from A

towards B, it is forward bearing or fore Bearing (F.B.). If

the bearing of the line AB is measured from B towards A, it

is known as backward bearing or Back Bearing (B.B.), since

it is measured in backward direction.

Back bearing of line AB is fore bearing of line BA that is

equal to 180° +AB

. Similarly, the back bearing of line CD is

b. Bearing

Bearing of a line is measured with magnetic north (or with

south) in clockwise direction. The value of the bearing thus

ranges from 00 to 3600. A prismatic compass is graduated

in this system.

Bearing and distance allow us to locate the point with

respect to a benchmark.

fore bearing of line DC that is equal to CD

–180°. Thus, in

general, it can be stated that B.B. = F.B. ± 180°, using plus

sign when F.B. is less than 1800 and minus sign when F. B.

is greater than 180°.

HS A B

Horizontal Ground A

B

Ө

SL

H

Horizontal Distance Measured in Sloping ground, HS = SL * Cos Ө


c. Elevation

For many purposes, location of the object or point is

required with respect to elevation. For which measurement

in distance, bearing, and elevation is required.

Generally, surveying is done to know the distance, bearing

and elevation of an object or point.

2. Survey information

When designing soil conservation and watershed

management activities, one needs to know distance, plan,

profile, cross section, and area.

a. Distance: Linear measurement between two points

expressed in horizontal distance.

b. Plan: Map indicating different points and objects in

the horizontal plane.

c. Profile: A vertical section of the Earth’s crust showing

the different horizons or layers. It is a map or drawing

showing the horizontal distance and elevation of

different objects / points.

Field measurement for profile leveling (with

Abney’s level or clinometer and measuring tape) -

Take two rods or sticks of the eye height. From the

upper selected site target a clinometer on the top of

the rod at the first site and read the slope in percent

holding the clinometer at the tip of the rod upstream.

E

1 Ro

P

Rod

P

3 Rod

P

2

Rod

H

1

Tape

H”2

Tape H

’2

Tape

E

2

Point P1 to P

2P

2 to P

3P

3 to P

4

Horizontal Distance H1

H2 = H’

2 + H”

2

Slope in % S1

S2

Magnetic Bearing B1

B2

Elevation Diff. E1

E2

Note the slope in percent and measure the horizontal

distance with a tape. While measuring the distance,

keep the tape horizontal. If the distance is too long

or the elevation difference is too high for any person

to hold horizontally, either measure the horizontal

distance in steps or measure the sloping distance and

later convert into horizontal distance for plotting. Also,

measure the bearing, preferably magnetic bearing.

d. Cross section: A section formed by a plane cutting

through an object, usually at right angles to an axis.

Cross section is a dimension measured generally

perpendicular to profile.

How to measure?

To measure the cross- section, stretch a measuring

rope at right angles to the main line of section at a

height of more than 5 meters depending upon the

condition of the site. Then, with a measuring rod start

from one end, to measure the depth of the gully bed

considering the rope as base line and distance from

one end as starting point. The distances are measured

left and right from the center peg. The readings are

entered in tabular form in Table with solved example.

Plotting of the depth and distance will give the cross

sectional profile. Always, it is important to start the

measurements from one side for all sections.


Annex 4. Landslide Treatment Techniques9

Landslide treatment and mitigation uses several

different conservation techniques that may be broadly

categorized into vegetative and structural techniques.

Vegetative techniques include: grass planting, mulching,

bamboo planting, buffer strips, conservation plantation,

fascine, palisade, brush layering, and wattling. Structural

techniques include rip-rap, waterways, bolster, retaining

wall, check dam, and conservation pond.

9 Source: Modified from DSCWM 2004, Soil Conservation and Watershed Management Measures and Low Cost Techniques. Soil

Conservation and Watershed Management Component (SCWMC), Natural Resource Management Sector Assistance Programme

(NARMSAP), Department of Soil Conservation and Watershed Management (DSCWM), Babar Mahal.


Titl

e: G

RASS

PLA

NTI

NG

Wha

t is

it?

Plan

ting

of g

rass

(se

ed, c

lum

p, r

hizo

me,

cut

tings

). P

lant

ed in

con

tour

, ver

tical

or

diag

onal

Sket

chFu

ncti

onLi

mit

atio

n

•

Arm

or (

Prot

ects

sur

face

fro

m r

aind

rops

by

prov

idin

g gr

ound

cov

er).

• Im

prov

e in

filtr

atio

n th

us r

educ

ing

runo

ff.

• Ca

tch

soil

mat

eria

l and

rei

nfor

ce s

lope

s.

• La

bor

inte

nsiv

e.•

Onl

y go

od f

or s

hallo

w s

mal

l lan

dslip

s.•

Som

e sp

ecie

s m

ay s

prea

d as

wee

d.

Type

Cont

our

Vert

ical

Dia

gona

l

Adv

anta

geIn

crea

ses

infil

trat

ion

and

catc

hes

soil

mat

eria

l. Pr

oduc

es f

orag

e.Ch

anne

lizes

run

off

and

less

infil

trat

ion.

Pr

oduc

es f

orag

e.Co

mbi

nes

the

best

fea

ture

s of

bot

h co

ntou

r an

d ve

rtic

al.

Prod

uces

for

age.

Dis

adva

ntag

eCa

n tr

igge

r liq

uefa

ctio

n du

e to

in

crea

se in

infil

trat

ion.

sCa

n de

velo

p ri

lls d

own

the

slop

es d

ue t

o ru

noff

. Ca

n de

velo

p sm

all r

ills

dow

n th

e sl

opes

on

wea

k m

ater

ial.

Som

e sp

ecie

s m

ay s

prea

d as

wee

d.

Plan

ting

ste

ps

• Pr

epar

e th

e si

te w

ell i

n ad

vanc

e fo

r pl

antin

g. F

ill t

he d

epre

ssio

ns a

nd c

lear

pro

trus

ions

. Sm

ooth

the

sur

face

so

that

the

re is

now

here

for

ero

sion

to

star

t. If

the

site

is

ba

ckfil

l mat

eria

l, it

shou

ld b

e th

orou

ghly

com

pact

ed, p

refe

rabl

y w

hen

wet

.•

Alw

ays

star

t pl

antin

g gr

ass

at t

he t

op o

f th

e sl

ope

and

wor

k do

wnw

ards

.•

Mar

k th

e lin

es w

ith s

trin

gs w

here

gra

ss is

to

be p

lant

ed. E

nsur

e th

at t

he li

nes

follo

w t

he c

onto

ur o

r de

sire

d an

gle

(Ver

tical

or

diag

onal

).•

Split

the

gra

ss s

lips

to m

axim

ize

the

amou

nt o

f pl

antin

g m

ater

ial.

Trim

off

long

roo

ts a

nd c

ut t

he s

hoot

s at

abo

ut 1

0 cm

abo

ve g

roun

d le

vel.

Wra

p th

e sl

ips

with

dam

p

he

ssia

n to

kee

p th

em m

oist

unt

il th

ey a

re p

lant

ed. R

emem

ber

that

you

will

nee

d tw

o sl

ips

per

drill

(pl

antin

g ho

le)

if th

e gr

ass

is a

fibr

ous

root

ing

type

(e.

g. b

abiy

o,

ka

ns, k

har,

phu

rke,

etc

.) b

ut o

nly

one

if it

is r

hizo

mat

ous

(e.g

. am

liso,

pad

ang

bans

, etc

.) a

nd o

nly

one

stem

cut

ting

(roo

ted)

or

seed

ling.

• W

ith a

pla

ntin

g ba

r, m

ake

a ho

le ju

st b

ig e

noug

h fo

r th

e ro

ots/

rhiz

omes

/cut

tings

. Pla

ce t

he g

rass

into

the

hol

e. F

ill t

he s

oil i

n ar

ound

the

m, p

ress

the

soi

l gen

tly

with

your

fing

ers.

•

If co

mpo

st o

r m

anur

e is

ava

ilabl

e, s

catt

er a

few

han

dful

s ar

ound

the

gra

sses

. Thi

s is

esp

ecia

lly im

port

ant

on v

ery

ston

y si

tes,

whe

re c

ompo

st o

r m

anur

e ca

n he

lp t

o

im

prov

e ea

rly

grow

th. Y

ou m

ay h

ave

to in

corp

orat

e co

mpo

st in

to t

he s

urfa

ce m

ater

ial t

o pr

even

t it

bein

g w

ashe

d of

f.•

If it

look

s ra

ther

dry

and

the

re is

no

pros

pect

of

rain

for

a d

ay o

r tw

o, c

onsi

der

wat

erin

g th

e pl

ants

by

hand

.

•

Mat

eria

lsSp

ecie

s To

ols

Gra

ss p

lant

s (c

lum

p,

rhiz

ome,

cut

ting)

Th

ysan

olae

na m

axim

a, E

ulal

iops

is b

inat

a, N

eyra

udia

rey

naud

iana

, Sac

char

um

spon

tane

um, T

hem

eda

spec

ies,

Cym

bopo

gon

mic

roth

eca,

Vet

iver

ia la

wso

ni,

Aru

ndo

clon

ax, P

enni

satu

m p

urpu

reum

, Him

alay

acal

amus

hoo

keria

nus,

Aru

ndue

lla

nepa

lens

is, N

eyra

udia

aru

ndin

acea

, Dre

pano

stac

hyum

inte

rmed

ium

, Vet

iver

, Cy

nodo

n da

ctyl

on, e

tc.

• Sh

ort

plan

ting

bars

•

Line

str

ing

/ Ta

pe m

easu

re (

30 m

eter

s)•

A m

eans

of

tran

spor

ting

plan

ts t

o si

te•

Hes

sian

and

wat

er t

o ke

ep t

he p

lant

ing

stoc

k m

oist

until

pla

ntin

g

Spac

ing:

Wit

hin

row

s: 1

0 cm

apa

rt e

xcep

t pa

dang

, am

liso

and

tite

niga

lo b

ans,

whi

ch s

houl

d be

spa

ced

30-5

0 cm

Plan

ting

per

iod

Row

Spa

cing

: Dep

ends

larg

ely

on t

he s

teep

ness

of

the

slop

e

Row

spa

cing

• D

urin

g th

e do

rman

t se

ason

if t

he s

ite is

moi

st.

• Ju

st b

efor

e m

onso

on if

the

site

is d

ry (

May

- Ju

ne)

Cont

our

Vert

ical

Dia

gona

l

Slop

e <

30

: 100

cm

Slop

e 30

– 4

5 :

50

cmSl

ope

> 45

:

30

cm

50 c

m50

cm

On

agric

ultu

re la

nd, fi

nd a

com

prom

ise

betw

een

ease

of

cult

ivat

ion

and

redu

ctio

n of

soi

l and

wat

er m

ovem

ent.

A

ver

tical

inte

rval

of

2 m

eter

s or

mor

e is

gen

eral

ly a

dequ

ate.

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(Sit

e fo

r ap

plic

atio

n)

• In

volv

es p

rote

ctio

n, w

eedi

ng, a

nd c

uttin

g fo

r ne

w g

row

th.

• Re

gula

rly

trim

the

gra

ss p

lant

ed o

n ri

ser

to p

reve

nt

th

em f

rom

sha

ding

and

spr

eadi

ng o

n fa

rmla

nd.

• Pr

otec

t ar

ea f

rom

the

fire

• En

sure

tha

t th

e ro

ots

have

not

tan

gled

or

have

cur

ved

back

to

the

surf

ace.

• Ta

ke c

are

to a

void

leav

ing

air

pock

et b

y th

e ro

ots

durin

g

pl

antin

g.

• A

lmos

t an

y sl

opes

less

tha

n 65

. Mos

tly

wel

l dra

ined

soi

ls w

here

incr

ease

in in

filtr

atio

n is

unl

ikel

y to

caus

e pr

oble

ms.

• Ri

ser

/ ri

m o

f th

e cu

ltiv

ated

fiel

ds.

Refe

renc

es: D

OR,

199

9. F

AO

and

IIRR

, 199

5, D

SCW

M 2

004.


Titl

e: M

ULC

HIN

G F

OR

SLO

PE S

TAB

ILIZ

ATI

ON

Wha

t is

it?

Tech

niqu

e of

cov

erin

g so

il su

rfac

e te

mpo

rari

ly in

ord

er t

o m

aint

ain

soil

moi

stur

e, p

rote

ct s

eeds

fro

m w

ashi

ng, a

nd c

reat

e

favo

rabl

e co

nditi

ons

for

plan

ts t

o es

tabl

ish.

Sket

chFu

ncti

onLi

mit

atio

n

•

Prot

ects

soi

l fro

m r

aind

rop

eros

ion,

hea

t, f

rost

, and

win

d.

• Re

duce

s ev

apor

atio

n th

us c

onse

rves

moi

stur

e.

• A

rmor

s so

il te

mpo

rari

ly.

• Co

ntro

ls w

eeds

.

• Re

quir

es h

uge

quan

tity

of m

ulch

ing

mat

eria

l.

• La

bor

inte

nsiv

e.

Not

e: P

last

ic m

ulch

is n

ot c

onsi

dere

d to

be

very

pra

ctic

al

for

slop

e st

abili

zatio

n.

Adv

anta

ges

Dis

adva

ntag

es

• O

rgan

ic m

ulch

incr

ease

s or

gani

c m

atte

r, m

icro

bial

act

ivity

,

m

oist

ure

in s

oil,

thus

incr

ease

s pr

oduc

tion.

• H

elps

see

d ge

rmin

atio

n.

• La

bor

dem

andi

ng d

urin

g co

llect

ion

• M

ay in

crea

se in

sect

s (t

erm

ite)

and

pest

s (r

oden

t)

• Ri

sk o

f fir

e ou

t br

eak

• •

Mul

chin

g st

eps

• Pr

epar

e th

e la

nd

• Co

llect

and

cho

p m

ulch

mat

eria

ls

• So

w t

he g

rass

see

ds t

hen

spre

ad t

he m

ulch

to

cove

r th

e en

tire

surf

ace.

• If

the

slop

e is

mod

erat

e to

ste

ep o

r th

e ar

ea h

as p

reva

iling

win

ds, m

ulch

nee

ds t

o be

pro

tect

ed f

rom

blo

win

g. P

rote

ct t

he m

ulch

ei

ther

with

w

ide

mes

h ju

te n

et a

s sh

own

in t

he p

ictu

re a

t to

p or

tie

d to

geth

er w

ith s

ticks

as

show

n in

mid

dle

pict

ure.

• In

usi

ng P

last

ic F

ilm (

PF),

aft

er s

prea

ding

pla

stic

she

et, p

ress

the

edg

es w

ith w

et s

oil a

t le

ast

10 c

m, (

to p

reve

nt f

rom

bei

ng b

low

n

of

f by

the

win

d)

• • • •

Mat

eria

ls

Tool

s

• M

ulch

ing

mat

eria

l: Pl

ant

resi

dues

(st

raw

, sta

ck, h

usk,

and

stu

bble

),

leaf

litt

ers,

saw

dust

/ash

, wee

ds e

tc.

• Sp

read

ing

Rake

• D

oko

(Bam

boo

bask

et)

••

Sick

le

Spec

ifica

tion

Cons

truc

tion

per

iod

Slop

e >

30 Æ

cove

r m

ulch

with

wid

e m

esh

jute

nett

ing

(150

*500

mm

mes

h) t

o ho

ld m

ulch

.

• M

ulch

ing

befo

re t

he m

onso

on t

o pr

otec

t so

il an

d se

eds

from

wat

er e

rosi

on

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(Sit

e fo

r ap

plic

atio

n)

• Sp

read

out

the

mul

ch if

it a

ccum

ulat

ed in

pl

aces

.

• D

on’t

use

pla

nt p

arts

car

ryin

g se

eds

(as

this

may

beco

me

a w

eedi

ng p

robl

em)

Prev

ent

from

fire

or

win

d an

d co

ntro

l rod

ents

.

• H

arsh

are

as (

Red

soil,

Dry

and

fro

st p

rone

are

a)

• U

p to

45 Æ

slo

pes

and

wel

l dra

ined

soi

ls

• N

urse

ry

Refe

renc

es: D

OR,

199

9. F

AO

and

IIRR

, 199

5. R

ongs

en, L

u, 1

994.

, DSC

WM

200

4.

Non

mul

ch a

rea

mul

ch a

rea


Titl

e: B

AM

BOO

PLA

NTI

NG

Wha

t is

it?

Pla

ntin

g of

bam

boo

for

soil

cons

erva

tion

and

wat

ersh

ed m

anag

emen

t.

Sket

chFu

ncti

onLi

mit

atio

n

• Re

info

rces

soi

l aga

inst

ero

sion

.

• Pr

ovid

es e

xcel

lent

sup

port

to

the

slop

e if

pl

ante

d at

the

bas

e /

toe

slop

e.

• Re

duce

s th

e ve

loci

ty o

f ru

n-of

f w

ater

.

• Tr

aps

soil

erod

ed f

rom

up

slop

e.

• W

orks

as

a fe

nce.

• N

othi

ng e

lse

can

grow

clo

se t

o ta

ll ba

mbo

o, m

ainl

y du

e to

sh

adin

g an

d nu

trie

nts

and

moi

stur

e co

mpe

titio

n.

• Ba

mbo

o se

eds

are

rare

ly s

ets;

see

ds m

ay n

ot b

e av

aila

ble

du

ring

nee

d fo

r se

edlin

g pr

oduc

tion.

Adv

anta

ges

Dis

adva

ntag

es

• Fo

dder

ava

ilabl

e fo

r an

imal

s (D

. hoo

keri

, B.

nu

tans

/ c

upal

ata

and

Am

pelo

cala

mus

pate

lla

ris

bans

).

• M

ater

ials

for

bas

kets

, Dok

o, M

ats

etc.

(Am

pelo

cala

mus

pate

llar

is, D

. hoo

keri

)

• Po

les

and

bam

boo

stra

ps u

sefu

l for

hou

se

co

nstr

uctio

n. (

D. h

ooke

ri, N

igal

o, B

. nut

ans

and

B.

nut

ans

/ cu

pala

ta B

ans)

• Ed

ible

sho

ots

(Den

droc

alam

us h

amilt

onii

Bans

)

• Pr

ovid

e op

port

uniti

es f

or IG

A

• La

rge

clum

ping

nat

ure

• Ba

mbo

o ca

sts

shad

e to

nea

rby

plan

ts

• H

abita

t fo

r pe

sts

• W

hole

pla

nt d

ies

afte

r se

edin

g

• G

row

th f

rom

the

see

d is

ver

y sl

ow

Prop

agat

ion

step

s

Bam

boo

Prop

agat

ion

Vege

tativ

e pr

opag

atio

n by

Clu

mp

cutt

ing

• O

ff-c

ut s

tem

s w

ith a

por

tion

of r

hizo

me

with

bud

fro

m 1

-1.5

m o

f 1-

year

-old

cul

m.

• Tr

ansp

lant

dir

ectl

y to

a fi

eld

site

or

to a

nur

sery

for

the

use

as

mot

her

stoo

l. Th

is m

etho

d is

si

mpl

e an

d us

ed f

or t

hose

spe

cies

tha

t fo

rm c

lum

p.

Vege

tativ

e Pr

opag

atio

n fr

om N

odal

cut

ting

• Se

lect

the

6-1

0-m

onth

old

cul

m,

• Cu

t th

e ba

mbo

o be

low

the

firs

t no

de w

ith a

bud

,

• Tr

im b

ack

all t

he m

ain

side

bra

nche

s.

• Tr

im o

ff a

ll ot

her

smal

ler

bran

ches

(pr

efer

ably

with

a s

ecat

ure

/ s

aw).

• Cu

t th

e cu

lm in

to p

iece

s (p

refe

rabl

y w

ith s

aw)

with

tw

o-no

des.

Spe

cies

with

larg

e br

anch

es li

ke T

aru

Bans

si

ngle

nod

e cu

ttin

g is

rec

omm

ende

d.

• Ke

ep a

ll pr

epar

ed s

egm

ents

in t

he s

hade

and

und

er m

oist

jute

sac

k or

wet

pap

er u

ntil

they

are

pla

nted

.

• Tr

ansp

ort

them

to

the

nurs

ery

as s

oon

as p

ossi

ble

afte

r pr

epar

atio

n.


• Fi

ll th

e ho

llow

spa

ce o

f th

e cu

ttin

gs w

ith w

et m

ud a

nd p

lace

cut

tings

hor

izon

tally

in t

renc

hes

in t

he n

urse

ry

be

ds a

nd b

ury

2.5-

15 c

m b

elow

the

sur

face

of

the

soil

imm

edia

tely

. In

two-

node

cut

tings

, a h

ole

can

be m

ade

in

the

cen

tral

inte

rnod

es a

nd fi

lled

with

wat

er. I

f th

ere

is t

erm

ite p

robl

em, t

reat

soi

l with

app

ropr

iate

pes

ticid

e.

• Pr

epar

e th

e so

il of

the

nur

sery

bed

in a

dvan

ce (

best

mix

is 3

:1:1

, soi

l, sa

nd, c

ompo

st).

• Co

nstr

uct

the

shad

e co

ver

stan

d at

80

cm h

igh.

• Th

e bu

d or

bra

nch

shou

ld f

ace

upw

ards

in s

ingl

e-no

de c

uttin

gs a

nd s

idew

ays

in d

oubl

e no

de c

uttin

gs.

• Th

e nu

rser

y be

d sh

ould

be

wat

ered

imm

edia

tely

and

kep

t m

oist

. Flo

od ir

riga

tion

prev

ents

ter

mite

att

ack.

• Li

ft n

odal

cut

tings

whe

n ne

w s

hoot

s gr

ow t

o ab

out

1 m

tal

l. Th

us p

repa

red

noda

l pla

nts

can

be p

lant

ed in

just

be

fore

or

duri

ng m

onso

on.

Sket

chPr

opag

atio

n st

eps

N

odal

cut

ting

is s

uita

ble

for

the

larg

er, c

lum

p fo

rmin

g sp

ecie

s th

at g

row

adv

entit

ious

roo

ts f

rom

nod

al b

uds

fair

ly

easi

ly. H

owev

er, t

his

tech

niqu

e ne

eds

cons

ider

able

car

e in

the

nur

sery

.

Pack

ing

for

tran

spor

tatio

n: C

ut d

oubl

e-no

de c

uttin

gs in

to s

epar

ate

plan

ts. T

rim

off

old

par

ent

inte

r-no

de m

ater

ials

clos

e to

the

nod

e. If

the

tra

nspo

rtat

ion

dist

ance

is lo

ng, w

rap

with

wet

new

spap

er o

r ju

te s

ack.

The

see

dlin

gs

shou

ld b

e pl

ante

d im

med

iate

ly a

fter

the

ir a

rriv

al a

nd ir

riga

te t

hem

just

aft

er p

lant

ing.

The

rate

of

surv

ival

in t

he fi

eld

will

be

mor

e th

an 8

5% if

the

y re

ceiv

e w

ater

reg

ular

ly a

nd a

re w

ell l

ooke

d af

ter

Prop

agat

ion

by s

eed:

Seed

s ar

e co

llect

ed in

late

spr

ing.

Sep

arat

e so

und

seed

s by

floa

ting

off

dead

see

ds a

nd u

nwan

ted

mat

eria

ls in

a

buck

et o

f w

ater

. (25

,000

-35,

000

seed

s pe

r kg

). S

eeds

sho

uld

be s

own

as s

oon

as p

ossi

ble

afte

r co

llect

ion.

The

y

cann

ot b

e st

ored

for

a lo

ng t

ime

(2-3

mon

ths

afte

r ha

rves

ting)

.

Sow

see

ds d

irec

tly

into

pre

pare

d se

edbe

d (u

sing

a s

oil m

ix o

f 3:

1:1

soil,

san

d, &

com

post

). G

erm

inat

ion

will

beg

in

one

wee

k af

ter

sow

ing.

Kee

p w

ell-

wat

ered

. Tra

nspl

ant

to 4

” *

7” p

olyp

ots

whe

n th

e se

edlin

gs a

re 5

to

10 c

m t

all.

The

seed

ling

shou

ld b

e tr

ansp

lant

ed w

hen

they

are

one

-yea

r-ol

d or

abo

ut 7

5-90

cm

tal

l.

Mat

eria

lsSp

ecie

s To

ols

Bam

boo

culm

Seed

Culm

with

rhi

zom

e

That

chin

g m

ater

ials

Den

droc

alam

us h

amilt

onii

(Tam

a ):

300

-200

0 m

, gro

ws

best

in m

oist

and

shad

y si

tes,

not

goo

d in

sou

th f

ace

belo

w 1

200

m L

arge

leav

es,

thin

cul

m, h

eavy

bra

nchi

ng, c

ulm

spl

it ea

sily

D. h

ooke

ri (

Kalo

): 1

200-

2500

m, H

eavy

bra

nchi

ng a

nd b

row

n ha

ir

Bam

busa

bal

cooa

(D

hanu

): T

erai

to

1600

m, l

arge

clu

mpi

ng, t

hin

and

heav

y br

anch

ing

stra

ight

cul

m)

B. n

utan

s /

cupa

lata

(M

al):

Ter

ai t

o 15

00 m

, St

rong

and

str

aigh

t

culm

Am

pelo

cala

mus

pate

llar

is (

Gho

pi):

120

0-20

00 m

, Sm

alle

r bl

uish

culm

B. n

utan

s (

Taru

): T

erai

to

1500

m, s

tron

g

Dig

ging

too

ls

Saw

Shar

p to

ol f

or

cutt

ing

Wat

er c

an

Dok

o

Sack

Dou

ble

node

cut

ting

wit

h ho

le f

or w

ater

ing

Dou

ble

node

cut

ting

wit

h sh

oots

and

roo

ts.


Spec

ifica

tion

Plan

ting

per

iod

5 *

5 m

Plan

t du

ring

spr

ing

(Feb

ruar

y -

May

) se

ason

if s

ite is

moi

st.

Just

bef

ore

mon

soon

(Ju

ne)

if th

e si

te is

dry

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(Sit

e fo

r ap

plic

atio

n)

Prot

ect

from

ani

mal

s, c

arry

out

wee

ding

, and

allo

w n

ew s

hoot

s to

grow

for

5 y

ears

.

Mak

e pr

ovis

ions

for

dra

inag

e.

Culm

har

vest

sho

uld

star

t fr

om t

he

olde

st o

ne (

Culm

mat

ures

in a

roun

d

2.5-

3 ye

ars

of a

ge.)

Care

mus

t be

tak

en t

o pr

otec

t th

e no

des

and

the

buds

on

the

rhiz

ome

duri

ng

digg

ing

and

tran

spor

tatio

n.

Culm

mus

t be

pro

tect

ed f

rom

dis

turb

ance

(sh

akin

g) a

fter

pla

ntin

g.

Bam

boo

shou

ld n

ot b

e ha

rves

ted

duri

ng t

he s

prou

ting

seas

on.

Prot

ect

plan

ting

stoc

k fr

om d

irect

sun

light

dur

ing

tran

spor

tatio

n.

Stee

p ba

nks,

gul

lies,

foo

t of

the

slo

pe, l

ive

chec

k da

m, b

rush

woo

d

chec

k da

m, a

nd w

attl

ing.

Aro

und

farm

hous

e as

fen

cing

(ei

ther

live

or

dead

).

Refe

renc

es: M

cCra

cken

, I. J

. (ed

.), 1

992,

DSC

WM

200

4.


Refe

renc

e: -

Bhi

may

a, C

.P. 1

976;

Cos

tin, E

., 19

76; D

anie

ls, R

. B.,

and

J. W

. Gill

iam

. 199

6; F

AO

, 197

6; H

ai C

hunx

ing,

Wan

d D

ongm

ei, W

ang

Yaol

in, 2

007.

; DSC

WM

200

4; T

he C

hine

se S

oil a

nd W

ater

Cons

erva

tion

Soci

ety,

198

7.; B

uffe

rs a

nd V

eget

ativ

e Fi

lter

Strip

s M

atth

ew J.

Hel

mer

s.

Titl

e: B

UFF

ER S

TRIP

Wha

t is

it?

Plan

ting

of a

per

man

ent

belt

of

eros

ion

resi

stan

t ve

geta

tion

(tre

es, s

hrub

s an

d gr

ass)

gen

eral

ly a

cros

s th

e sl

ope.

Sket

chFu

ncti

onLi

mit

atio

n

• In

terc

epts

run

off

and

sedi

men

t fr

om a

djoi

ning

(up

-slo

pe)

land

s an

d re

duce

impa

ct o

n

do

wn-

slop

e ar

ea f

rom

run

off

and

sedi

men

t•

Prot

ects

adj

oini

ng la

nd f

rom

ban

k er

osio

n su

ch a

s al

ong

the

stre

am o

r la

ke o

r se

a.•

crea

tes

effe

ctiv

e ba

rrie

r to

red

uce

impa

cts

such

as

pollu

tion

• Re

duce

s sa

lt d

amag

e if

the

loca

lity

is n

ear

the

sea.

• D

ifficu

lt t

o es

tabl

ish

in s

teep

slo

pes.

(>50

deg

rees

)

Adv

anta

ges

Dis

adva

ntag

es

• Co

nser

ves

soil

and

moi

stur

e fo

r be

tter

pro

duct

ion

• Sh

rubs

and

gra

sses

hel

p to

slo

w fl

oodi

ng a

nd p

rote

ct c

rops

fro

m fl

ood

dam

age,

• Re

duce

s m

aint

enan

ce o

f di

tch

from

sed

imen

tatio

n.•

Whe

re w

ind

is a

fac

tor,

tre

es a

nd s

hrub

s gr

owin

g in

the

buf

fer

incr

ease

the

buf

fer’

s ab

ility

to

prev

ent

win

d fr

om e

rodi

ng v

alua

ble

tops

oil.

Impr

oves

aes

thet

ic lo

oks

• O

ccup

ies

prod

uctio

n la

nd•

Shad

es a

nd c

ompe

tes

with

cro

ps f

or

nu

trie

nts

and

wat

er.

• H

abita

t fo

r bi

rd a

nd in

sect

s•

Obs

truc

ts f

ree

mov

emen

t of

mac

hine

ries

Plan

ting

ste

ps

• U

sing

“A

” fr

ame

mar

k th

e lin

es t

o be

pla

nted

. •

Prep

arat

ion

of la

nd f

or p

lant

ing

• Se

ed t

reat

men

t (S

eed

is s

oake

d in

wat

er t

o en

hanc

e ge

rmin

atio

n)•

Plan

t th

e tr

ees,

shr

ubs,

and

gra

ss s

aplin

gs o

r se

ed•

If av

aila

ble,

use

com

post

/man

ure

or f

ertil

izer

for

initi

al g

row

th.

Mat

eria

lsSp

ecie

s To

ols

Plan

ting

mat

eria

l: Se

ed, S

eedl

ing,

cut

tings

, sl

ips

Crite

ria f

or s

elec

tion

of s

peci

es: -

• Fa

st g

row

ing

• D

eep

root

ing

syst

em (

Dee

p ro

oted

gra

ss,

sh

rubs

and

tre

es)

• A

bilit

y to

cop

pice

• Ec

onom

ic v

alue

.

Som

e sh

rubs

and

bus

hes

conv

enie

nt t

o pl

ant

on r

ipra

p (H

owel

l, et

al

. 199

1):

Adh

atod

a va

sica

(as

suro

), D

uran

tha

repe

ns (

Nilk

andh

a), E

upho

rbia

ro

ylea

na (

Siul

i), J

atro

pha

curc

as (

Sajiw

an),

Vite

x ne

gund

o (s

imal

i),

Salix

, Aca

cia

penn

ata,

But

ea m

inor

Som

e re

com

men

ded

gras

ses

to p

lant

:A

rund

o cl

onax

(N

arka

t); P

ogon

athe

rum

pan

icum

(M

usek

haru

ki);

Cy

nodo

n da

ctyl

on (

Dhu

bo);

Vet

iver

spe

cies

; Thy

sano

laen

a m

axim

a (A

mlis

o); C

ymbo

pogo

n m

icro

thec

a (K

har)

• ‘A

’ Fr

ame

• M

easu

ring

tap

e•

Stri

ng•

Dig

ging

Hoe

or

spad

e

Spec

ifica

tion

Plan

ting

per

iod

• Se

vera

l diff

eren

t co

mbi

natio

ns o

f ve

geta

tion

vary

ing

from

sim

ply

gras

s to

com

bina

tions

of

gr

ass,

tre

es, a

nd s

hrub

s.•

Buff

er s

trip

with

den

se g

rass

, shr

ubs,

and

tre

es is

mor

e ef

fect

ive.

• Se

ed s

owin

g or

see

dlin

g tr

ansp

lant

ing

shou

ld b

e do

ne w

ith t

he o

n-se

t of

mon

soon

.•

Cutt

ing

duri

ng w

inte

r

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(Sit

e fo

r ap

plic

atio

n)

• Re

plac

emen

t of

dea

d se

edlin

g•

Nec

essa

ry p

runi

ng a

nd w

eedi

ng t

o pr

omot

e un

derg

row

th o

f gr

ass

• Pe

st a

nd d

isea

se c

ontr

ol•

Onc

e bu

ffer

str

ip is

est

ablis

hed,

it r

equi

res

min

imal

mai

nten

ance

• Pr

otec

tion

of b

uffe

r st

rip f

rom

ille

gal c

uttin

g an

d gr

azin

g

• En

sure

buf

fer

stri

p is

alo

ng t

he c

onto

urs

for

inte

rrup

ting

runo

ff a

nd

se

dim

ent

from

ups

lope

• Th

e ve

geta

tion

on b

uffe

r st

rip

mus

t no

t be

dis

turb

ed b

y gr

azin

g

an

d ill

egal

cut

ting

• Th

e ve

geta

tion

mak

es m

inim

um c

ompe

titio

n w

ith a

djoi

ning

cro

ps

• A

long

the

ban

k of

the

str

eam

/ri

ver/

lake

/se

a•

Alo

ng t

he f

oot

slop

e w

here

run

off

and

sedi

men

t flo

w f

rom

ups

lope

is c

omm

on.

• A

cros

s th

e sl

ope,

inte

rcep

t ru

noff

and

sedi

men

t flo

w.


Titl

e: C

ON

SERV

ATI

ON

PLA

NTA

TIO

NW

hat

is it

? Pl

antin

g of

tre

e an

d sh

rub

spec

ies

usin

g so

il an

d m

oist

ure

cons

erva

tion

tech

niqu

es t

o pr

otec

t la

nd f

rom

deg

rada

tion

and

to im

prov

e th

e en

viro

nmen

t fo

r th

e pl

ant

grow

th.

Plan

ting

tec

hniq

ues

Cont

our

bund

s or

on

mou

nds

Hor

izon

tal p

latf

orm

or

benc

hes

Plan

tati

on o

n ba

sin

pit

Cons

erva

tion

con

tour

tre

nche

sSt

rip

plan

tati

on

Prob

lem

Wat

er lo

ggin

g or

ver

y w

et

cond

ition

s.

• Cr

eepi

ng o

f lo

ose

mat

eria

ls

• M

oist

ure

stre

ss.

Dry

and

har

sh s

oil c

ondi

tions

Dry

and

har

sh s

oil c

ondi

tion

Hig

h gr

ass

and

wee

ds

Sket

ch

Obj

ecti

ve•

To p

rote

ct s

eedl

ings

fro

m

floo

ding

and

impr

ove

aera

tion

• To

dra

in e

xces

s w

ater

• To

pro

tect

see

dlin

g fr

om

de

bris

• To

impr

ove

infil

trat

ion

and

so

il m

oist

ure.

• To

cat

ch r

ain

wat

er f

or p

lant

s

• To

impr

ove

infil

trat

ion

rate

an

d so

il m

oist

ure

• To

tra

p th

e er

oded

soi

l,

• To

cat

ch r

ainw

ater

for

pla

nts.

• To

ove

rcom

e pr

oble

ms

of

hi

gh g

rass

and

wee

ds.

Site

pre

para

tion

• Pr

epar

e m

ound

s or

ridg

es

w

ell i

n ad

vanc

e by

scr

apin

g

th

e to

p so

il an

d pi

ling

50-6

0 cm

hi

gh o

r ab

ove

the

high

wat

er

le

vel.

• If

the

soil

is s

alin

e, a

dd

gy

psum

.

• Pr

epar

e ho

rizon

tal p

latf

orm

60

–10

0 cm

wid

e at

st

agge

red

patt

ern,

• Co

nstr

uct

a rid

ge o

n

do

wns

lope

sid

e

• Sp

ace

plat

form

s 3

m a

part

.

• Sp

ace

the

plan

ts p

refe

rabl

y

2

m a

part

in t

he p

latf

orm

.

• Pr

epar

e sm

all r

ound

bas

ins

to

ca

tch

rain

wat

er in

a

st

agge

red

patt

ern

for

in

divi

dual

pla

nts,

pile

the

ex

cava

ted

soil

on t

he

do

wnh

ill s

ide

to h

old

ra

inw

ater

.

• Sp

acin

g be

twee

n pl

ants

is

us

ually

2 m

. It

coul

d va

ry t

o

su

ite t

he s

ites.

• D

ig c

onto

ur t

renc

hes

of 0

.4m

w

idth

, 0.5

m d

epth

,

an

d 4m

leng

th in

a

st

agge

red

patt

ern.

• D

ig a

pit

30cm

dee

p an

d

30

cm d

iam

eter

at

the

end

of

th

e tr

ench

.

• Sl

ope

the

tren

ch t

owar

ds t

he

en

d to

div

ert

the

harv

este

d

ra

in.

• Le

ave

1.5

- 3

m s

pace

be

twee

n th

e tr

ench

es.

• Re

mov

e gr

ass

in 3

m w

ide

co

ntou

r st

rips

• Pr

epar

e pi

ts in

the

str

ips

• Pl

ant

larg

e se

edlin

gs o

r bi

g

si

ze s

tem

cut

tings

• Pr

epar

e th

e si

te w

ell i

n ad

vanc

e (1

–2

mon

ths

befo

re)

• D

ig a

pit

of 4

5cm

x 4

5 cm

x 4

5cm

for

pla

ntin

g

• If

poss

ible

, fill

the

pits

with

goo

d so

il, c

ompo

st, a

nd c

ompl

ete

fert

ilize

r (N

PK).

Add

gra

ss, s

traw

, and

org

anic

mat

ter

in t

he p

its t

o re

tain

moi

stur

e (r

ecom

men

ded)

.

Plan

ting

tim

eBe

st a

t th

e en

d of

rai

ny s

easo

n in

wat

erlo

gged

are

as.

• Ca

rry

out

plan

tatio

n pr

ogra

m in

the

beg

inni

ng o

f th

e m

onso

on w

hen

the

soil

has

suffi

cien

t

m

oist

ure

to s

uppo

rt t

he e

stab

lishm

ent

of s

eedl

ings

.

• Pl

antin

g in

the

win

ter

is p

refe

rred

for

a c

uttin

g /

ste

m p

lant

atio

n.

Hig

h w

ater

leve

l

50-6

0 cm


Care

& m

aint

enan

ce•

Sele

ct s

eedl

ings

of

optim

um s

ize

with

wel

l-de

velo

ped

root

sys

tem

. Tri

m s

appy

sho

ots

and

leav

es t

o re

duce

tra

nspi

ratio

n.

• If

poss

ible

, wat

er t

he p

lant

s in

dry

per

iods

, use

man

ure

if th

e so

il is

ver

y po

or, a

nd p

ut m

ulch

to

redu

ce e

vapo

ratio

n an

d pr

otec

t th

e pl

ant

from

col

d or

hea

t.

• D

o re

gula

r w

eedi

ng f

rom

July

to

Oct

ober

at

leas

t fo

r th

e fir

st 3

yea

rs. P

rote

ct t

he s

ite a

gain

st g

razi

ng, fi

re h

azar

ds, a

nd d

amag

e by

peo

ple.

Oth

er c

onsi

dera

tion

s•

Site

s w

ith lo

ose

and

cree

ping

mat

eria

ls: s

elec

t pl

ant

spec

ies

that

can

dev

elop

roo

ts f

rom

ste

m (

will

ow, s

imal

i, kh

irro

). S

uch

plan

ts c

an t

oler

ate

inju

ry b

y de

bris

fro

m

up

slop

e to

som

e de

gree

.

• Ta

ke s

afet

y pr

ecau

tions

whi

le w

orki

ng o

n st

eep

slop

es.

• In

col

d an

d w

indy

pla

ces

like

Mus

tang

, pla

ntin

g of

1-2

m lo

ng a

nd 1

0-15

cm

dia

met

er c

uttin

g gi

ves

good

res

ults

.

• W

hile

pla

ntin

g cu

ttin

gs, t

he t

ip o

f cu

ttin

g ne

eds

to b

e w

axed

to

avoi

d de

sicc

atio

n.

• Pl

antin

g in

pot

s is

bet

ter

than

bar

e ro

ot p

lant

atio

n in

har

sh s

ites.

• O

n ro

cky

site

s, s

eedl

ings

can

be

plan

ted

on t

he b

est

avai

labl

e sp

ots

inst

ead

of r

egul

ar s

paci

ng.

• G

row

ing

legu

min

ous

spec

ies

alon

g w

ith o

ther

spe

cies

is r

ecom

men

ded

to r

ecla

im d

egra

ded

land

.

• Be

tter

to

use

loca

l fas

t gr

owin

g sp

ecie

s w

ith d

eepe

r ro

ot s

yste

ms.

• D

ispo

se o

f th

e po

ly b

ags

safe

ly.

Sket

chFu

ncti

onLi

mit

atio

n

•

Prot

ects

soi

l sur

face

fro

m r

aind

rops

by

prov

idin

g gr

ound

cov

er

• In

crea

ses

infil

trat

ion,

rec

harg

ing

the

grou

nd w

ater

, and

eva

po-t

rans

pira

tion

th

us r

educ

ing

runo

ff

• Re

duce

s th

e ve

loci

ty o

f th

e ru

noff

by

obst

ruct

ing

it

• Re

info

rces

slo

pes

• Re

cycl

es n

utrie

nts

from

dee

per

laye

r of

the

soi

l

• Fr

ee g

razi

ng c

anno

t be

allo

wed

,

• Fi

re o

utbr

eaks

may

dam

age

the

plan

ts.

• Ri

sk o

f di

seas

e &

pes

ts in

mon

ocul

ture

Adv

anta

ges

Dis

adva

ntag

es

• Re

duce

s er

osio

n an

d im

prov

ed la

nd q

ualit

y (p

hysi

cal,

chem

ical

, and

bio

logi

cal

pr

oper

ties

of s

oil)

• Im

prov

es w

ater

yie

ld (

qual

ity a

nd r

egim

e)

• M

akes

mul

tiple

out

puts

ava

ilabl

e --

Fue

l woo

d, f

odde

r, t

imbe

r, &

leaf

litt

ers

et

c.

• Im

prov

es b

iolo

gica

l div

ersi

ty

• Ro

ots

may

ope

n ro

ck jo

ints

and

cre

ate

unst

able

sl

opes

.

• Lo

ad o

f th

e la

rge

tree

s co

mbi

ned

with

the

dyn

amic

fo

rces

of

the

win

d ca

n in

duce

slo

pe f

ailu

re

• Ta

kes

time

for

esta

blis

hmen

t of

pla

ntat

ion

• Lo

ss o

f w

ater

thr

ough

tra

nspi

ratio

n

• La

rge

wat

er d

rops

fal

ling

from

the

leav

es m

ay

cr

eate

ero

sion

.

Plan

ting

ste

ps

• Id

entif

y th

e pl

antin

g si

te t

oget

her

with

loca

l peo

ple

• D

ivid

e th

e si

te in

to d

iffer

ent

area

s re

quir

ing

diff

eren

t pl

antin

g te

chni

ques

• Se

lect

sui

tabl

e sp

ecie

s is

bas

ed o

n ad

apta

bilit

y, m

ultip

le u

se, s

oil q

ualit

y, a

nd p

refe

renc

e of

the

loca

l peo

ple.

• Pr

epar

e th

e si

te (

site

sur

vey,

site

cle

aran

ce a

nd a

lignm

ent

of t

he p

lant

ing

pits

and

pitt

ing)

wel

l in

adva

nce

(1 –

2 m

onth

s be

fore

).

• If

poss

ible

, put

com

post

at

the

bott

om o

f pl

antin

g ho

le in

poo

r so

ils o

r ad

d a

good

for

est

soil,

and

leav

e fo

r fe

w w

eeks

to

cons

olid

ate

th

e lo

ose

soil

• Re

mov

e po

lyth

ene

bag

from

the

see

dlin

g by

cut

ting

the

side

car

eful

ly.

• Pl

ace

seed

ling

into

the

pit

and

pres

s th

e so

il fir

mly

aro

und

the

seed

ling


Mat

eria

lsTo

ols

Seed

lings

, cut

tings

, see

d et

c. d

epen

ding

on

the

prop

agat

ion

met

hod

of s

elec

ted

spec

ies

Surv

ey: M

easu

ring

tap

e /

rop

e /

com

pass

/ A

bney

’s

leve

l / p

egs

/ fi

eld

book

/ r

angi

ng r

od

Plan

ting

: Dig

ging

too

ls

Spec

ifica

tion

sPl

anti

ng p

erio

d

• Pi

t si

ze o

f 30

cm

dee

p an

d ab

out

30 c

m in

dia

met

er. (

Dee

per

pit

is b

ette

r)

• Sp

acin

g: 2

*2 m

for

tre

e an

d 1*

1 m

for

shr

ubs

• G

ener

ally

, see

dlin

g si

ze m

ust

be >

30

cm in

hei

ght.

• Pr

epar

e pl

antin

g pi

ts s

ome

wee

ks b

efor

e

pl

anta

tion.

• Ca

rry

out

plan

ting

at t

he o

nset

of

mon

soon

.

• W

inte

r pl

anta

tion

is b

ette

r fo

r th

e cu

ttin

g /

ste

m

pl

anta

tion

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(sit

e fo

r ap

plic

atio

n)

• W

eed

and

wor

k th

e so

il fo

r a

favo

rabl

e gr

owin

g

en

viro

nmen

t

• Re

gula

r th

inni

ng a

nd p

runi

ng t

o al

low

the

un

derg

row

th t

o gr

ow

• Ca

rry

out

enric

hmen

t pl

anta

tion

in t

he f

ollo

win

g

ye

ars

to fi

ll th

e ga

ps.

• Pr

otec

t th

e pl

anta

tion

site

aga

inst

gra

zing

, fire

haz

ards

, and

dam

age

by p

eopl

e

• Pl

ant

mix

ed s

peci

es t

o m

inim

ize

risk

of

mon

ocul

ture

• Se

lect

spe

cies

with

hig

h su

rviv

al r

ates

, fas

t gr

owin

g, s

ever

al la

yers

, and

hig

h

cr

own

cove

r de

nsity

.

• Pl

antin

g af

ter

mon

soon

or

duri

ng t

he f

all h

as lo

w s

urvi

val r

ate

• Tr

ansp

ort

seed

lings

car

eful

ly a

nd m

ake

sure

tha

t pl

antin

g st

ock

is n

ot a

llow

ed

to

dry

in t

he s

un

• Kh

arba

ri /

Gra

zing

land

s

• Co

mm

unity

and

pub

lic b

arre

n la

nds

• G

ully

and

land

slid

e

• Ri

ver

bed

• Ro

ad s

lope

s

• Co

mm

unity

for

est

Suit

able

spe

cies

For

impr

ovin

g so

il

fert

ility

& o

rgan

ic m

atte

r

For

dry

and

ston

y si

tes

For

poor

soi

l con

diti

ons

For

moi

st s

ites

For

swam

py s

ites

For

fodd

erFo

r ea

sy p

ropa

gati

on

Asu

ro, D

hain

cha,

Khi

rro,

Flem

engi

a, D

esm

odiu

m,

Utis

, Sis

au, R

ahar

, Ipi

l-

ipil,

Tep

hros

ia

Phal

edo,

Am

ala,

Chila

une,

Ket

uki,

Khirr

o

Am

ala,

bay

er, K

etuk

i,

Khai

r, B

akai

no, B

abul

,

sim

ali,K

alo

Siris

,

Teph

rosi

a, C

asua

rina

,

Siss

o, K

hirr

o

Bain

s, U

ttis

, Chi

laun

e,

Lalig

uras

Euca

lypt

us, L

ages

troe

mia

,

Spec

iosa

, Cas

uari

na

glau

ca, w

illow

spe

cies

.

Bada

har,

Bed

ulo,

Bhi

mal

,

Ipil

Ipil,

Dab

dabe

,

Dud

hilo

, Gog

an Jh

inga

t,

Flem

ingi

a, K

utm

iro,

Phal

edo,

Tank

i, Ko

iral

o,

Khan

yu, K

abro

,

Dab

dabe

, Jhi

ngar

t, s

imal

i,

Asu

ro, P

hale

do, K

hirr

o,

Bain

s, S

aru,

Sim

ali

Refe

renc

es: C

ampb

ell,

Gab

riel J

. and

Jean

nett

e D

enho

lm (

edt.

), 1

992.

Dat

ta, S

. K. 1

986.

DO

R, 1

999.

Hud

son,

N. 1

981.

Sax

ena

N. C

. and

Vis

hwa

Bal

labh

–19

95. T

ingf

u, G

uo, 1

992,

DSC

WM

200

4.


Titl

e: F

ASC

INE

Wha

t is

it?

Layi

ng o

f a

bund

le o

f liv

e br

anch

es b

ound

tog

ethe

r in

a s

hallo

w d

ug d

itch

or t

renc

hes

and

cove

ring

with

soi

l for

sp

rout

ing.

Sket

chFu

ncti

ons

Lim

itat

ion

• Ca

tche

s de

bris

• A

rmor

s an

d re

info

rces

the

slo

pe•

Incr

ease

s in

filtr

atio

n •

Prov

ides

fas

cine

sub

-sur

face

dra

inag

e on

slo

pes

• It

doe

s no

t fo

rm a

phy

sica

l bar

rier

imm

edia

tely

and

req

uire

s

a

peri

od o

f gr

owth

to

beco

me

effe

ctiv

e.•

The

max

imum

slo

pe w

here

it c

an b

e us

ed is

abo

ut 4

5Æ•

Onl

y su

itabl

e fo

r ri

lls a

nd s

mal

l gul

lies

Adv

anta

ges

Dis

adva

ntag

es

• Pu

t ou

t ro

ots

and

shoo

ts f

orm

ing

a st

rong

line

of

vege

tatio

n.•

Sim

ple

and

low

cos

t er

osio

n co

ntro

l mea

sure

s.

• Co

nstr

uctio

n ca

uses

dis

turb

ance

to

the

slop

es

• Re

quir

es a

larg

e am

ount

of

plan

t m

ater

ial

Cons

truc

tion

ste

ps

• Pr

epar

e th

e si

te w

ell i

n ad

vanc

e.•

Mar

k th

e lin

e, w

here

fas

cine

s ar

e to

be

inst

alle

d. E

nsur

e th

at t

he li

nes

follo

w t

he c

onto

ur o

r de

sire

d an

gle

or r

ills.

• D

ig t

renc

hes

abou

t 30

cm

dee

p an

d up

to

50 c

m w

ide.

Cle

ar a

ll lo

ose

mat

eria

l and

pro

trus

ion

and

firm

ly in

fill d

epre

ssio

ns.

• A

lway

s co

nstr

uct

fasc

ines

fro

m t

he b

otto

m o

f th

e sl

ope,

and

wor

k up

war

ds.

• D

ig a

bout

5 m

eter

s lo

ng t

renc

h at

a t

ime

and

lay

the

fasc

ine

bund

les

toge

ther

with

the

ir e

nds

over

lapp

ing

and

fill t

he

tr

ench

. Thi

s en

sure

s th

at t

he s

oil i

n th

e tr

ench

is e

xpos

ed o

nly

for

shor

t pe

riod

the

reby

min

imiz

ing

the

loss

of

soil

moi

stur

e.•

Prep

are

fasc

ine

bund

les

cons

istin

g of

5 –

8 b

ranc

hes

with

a m

inim

um d

iam

eter

of

one

cm e

ach.

The

com

plet

ed b

undl

es

sh

ould

be

15 t

o 20

cm

in d

iam

eter

, with

all

the

grow

ing

tips

orie

nted

in t

he s

ame

dire

ctio

n.•

Tie

the

fasc

ine

bund

le t

oget

her

with

1.5

to

2.0

mm

wir

e or

jute

or

coir

str

ing

at 5

0 cm

inte

rval

s.•

If th

e fa

scin

e lin

e is

ste

eper

tha

n 25Æ

, peg

the

fas

cine

with

a li

ve o

r de

ad p

egs

of a

t le

ast

60 c

m le

ngth

at

50 c

m a

part

.•

Back

fill t

he t

renc

h as

soo

n as

pos

sibl

e, c

over

the

fas

cine

s w

ith a

3-4

cm

of

soil,

and

tra

mp

the

soil

firm

ly.

Mat

eria

lsSp

ecie

sTo

ols

• Br

anch

es o

f di

ffer

ent

spec

ies

of

ro

otin

g pl

ants

6 t

o 18

mon

ths

old,

2

to

5 c

m d

iam

eter

, and

at

leas

t

1m lo

ng

• Sp

rout

ing

woo

den

pegs

(3-6

cm

dia

and

50-

100

cm lo

ng).

• Bi

ndin

g w

ire/

rope

Adh

atod

a va

sica

(as

suro

), E

ryth

rina

arbo

resc

enes

(Ph

aled

o), F

icus

laco

r (K

avro

), Ip

omea

fist

ulat

a (s

aruw

a),

Lant

ana

cam

ara

(phu

l kan

da),

Vite

x ne

gund

o (s

imal

i), S

alix

spe

cies

(b

ains

), G

agru

ga p

inna

ta (

dabd

abe)

, Se

pium

inse

gne

(khi

rro)

, etc

.

• H

essi

an a

nd w

ater

to

keep

the

cut

ting

moi

st u

ntil

plan

ting

• To

ols

to d

ig t

renc

h

Spec

ifica

tion

Cons

truc

tion

per

iod

• Sp

acin

g be

twee

n co

ntou

r fa

scin

es d

epen

ds o

n th

e st

eepn

ess

of t

he s

lope

.

Use

a 4

m in

terv

al f

or le

ss t

han

30Æ

slo

pe a

nd 2

m in

terv

al f

or

30Æ

45Æ

slop

e.•

If fa

scin

es a

re u

sed

on r

ills

or s

mal

l gul

lies,

it ju

st f

ollo

ws

the

rills

or

gulli

es.

• Th

e tr

ench

sho

uld

be a

bout

30

deep

and

up

to 5

0 cm

wid

e.•

For

each

fas

cine

, the

re s

houl

d be

at

leas

t fo

ur b

ut n

ot m

ore

than

eig

ht

br

anch

es.

• D

urin

g do

rman

t se

ason

if t

he s

ite is

moi

st•

Befo

re m

onso

on r

ain

if th

e si

te is

dry

(May

-Jun

e)


© WWF Nepal, Hariyo Ban Program/ Nabin Baral

Mai

nten

ance

Prec

auti

ons

Scop

e (S

ite

for

appl

icat

ion)

• In

spec

t th

e ar

ea d

urin

g th

e fir

st r

ainy

seas

on. R

epai

r an

y ex

posu

re /

bre

ak o

f

the

fasc

ines

• O

ccas

iona

l thi

nnin

g an

d pr

unin

g m

ay b

e

re

quire

d af

ter

a fe

w y

ears

.

• T

he b

utt

end

of t

he b

ranc

hes

shou

ld a

lway

s po

int

in t

he

sa

me

dire

ctio

n.•

If tr

ench

is d

eepe

r th

an 4

0 cm

fill

the

tren

ch w

ith g

rave

l.

• En

sure

tha

t w

ater

can

not

run

unde

r th

e bu

ndle

s an

d sc

our

them

out

.•

Fasc

ine

drai

n m

ust

conn

ect

to n

eare

st s

uita

ble

drai

nage

syst

em.

• Fa

scin

es a

re e

ffec

tive

on t

he s

hallo

w g

ullie

s or

dee

p ri

lls li

nes.

• Be

st u

sed

on c

onso

lidat

ed d

ebri

s or

sof

t cu

t sl

opes

.•

On

wel

l-dr

aine

d m

ater

ial,

use

cont

our

fasc

ines

; on

poor

ly d

rain

ed m

ater

ials

, a

he

rrin

gbon

e pa

tter

n of

fas

cine

s im

prov

es d

rain

age.

• Pr

otec

t sl

opes

fro

m s

hallo

w s

lides

(30

– 6

0 cm

dep

th).

Refe

renc

es: D

OR,

199

9, F

AO

, 198

5, D

SCW

M 2

004.


Titl

e: P

ALI

SAD

EW

hat

is it

? Li

ve s

prou

ting

cutt

ings

pla

ced

acro

ss t

he s

lope

or

smal

l gul

ly u

sual

ly f

ollo

win

g th

e co

ntou

r.

Sket

chFu

ncti

onLi

mit

atio

n

• Fo

rms

a st

rong

bar

rier

acr

oss

a gu

lly

• Re

info

rces

the

slo

pe

• Ca

tche

s de

bris

mov

ing

dow

n th

e sl

ope

• W

eak

to s

uppo

rt b

ig v

olum

e of

deb

ris.

Adv

anta

ges

Dis

adva

ntag

es

• Si

mpl

y an

d ea

sily

bui

lt w

ith im

med

iate

eff

ect

• Fo

rms

a st

rong

low

cos

t ba

rrie

r bu

ilt w

ith t

he m

inim

um d

istu

rban

ce t

o th

e sl

ope

• Li

ving

che

ck d

am f

or g

ullie

s w

ith p

erio

dic

flood

s. G

ood

mea

sure

aga

inst

gul

ly e

rosi

on

he

lps

to r

epai

r an

d fil

l the

gul

lies.

• U

sefu

l onl

y fo

r sm

all a

nd n

arro

w g

ullie

s

Cons

truc

tion

ste

ps

• A

lway

s st

art

at t

he t

op o

f th

e sl

ope

and

wor

k do

wnw

ards

. Mar

k th

e lin

es t

o pu

t th

e pa

lisad

e.

• U

sing

a p

oint

ed b

ar o

r cr

owba

r, m

ake

a ho

le b

igge

r th

an t

he c

uttin

g an

d de

ep e

noug

h to

tak

e at

leas

t tw

o-th

ird

of it

s le

ngth

.

• D

ig a

tre

nch

deep

eno

ugh

to t

ake

at le

ast

two-

thir

d of

leng

th o

f th

e cu

ttin

g ac

ross

the

gul

ly.

• Pl

ace

a cr

oss

beam

(10

cm

dia

met

er a

nd 2

m lo

ng)

to s

uppo

rt t

he c

uttin

gs.

• A

ncho

r th

e cr

oss

beam

with

peg

s (3

-6 c

m d

iam

eter

and

50

cm lo

ng).

Use

live

bea

ms

if av

aila

ble.

• Ta

ke 0

.5-1

m lo

ng c

uttin

gs f

rom

6-1

8 m

onth

s ol

d br

anch

es 3

to

5 cm

dia

met

er.

• Cu

t th

e br

anch

es a

t ri

ght

angl

e at

top

to

redu

ce d

ryin

g an

d at

45Æ

at

bott

om t

o gi

ve m

ore

spac

e fo

r ro

otin

g. If

pos

sibl

e, t

ake

the

cu

ttin

gs t

he s

ame

day

that

the

y ar

e to

be

plan

ted.

• Pl

ace

the

cutt

ings

sid

e-by

-sid

e (5

cm

apa

rt)

in t

he h

ole

so t

hat

at le

ast

1/3

is a

bove

gro

und

and

2/3

in t

he s

oil.

• Ti

e th

e st

akes

with

jute

or

coir

wir

e w

ith c

ross

bea

m

• Fi

ll an

d fir

mly

tra

mp

the

soil

arou

nd it

. Cle

ar a

ny lo

ose

or e

xces

s m

ater

ial d

own

slop

e.

• Su

ppor

t pa

lisad

e w

ith s

tone

and

soi

l fro

m lo

wer

sid

e on

ste

ep s

lope

.

• If

a do

uble

line

is u

sed,

the

n a

seco

nd li

ne is

pla

ced

10 c

m b

ehin

d th

e fir

st a

nd w

ith t

he in

divi

dual

cut

tings

off

set

to c

oinc

ide

with

th

e ga

ps b

etw

een

the

cutt

ings

in t

he fi

rst

line.

Mat

eria

lsSp

ecie

sTo

ols

• 0.

5 –

1 m

. lon

g cu

ttin

gs o

f di

ffer

ent

spec

ies

fr

om 6

-18

mon

ths

old

bran

ches

of

3

to 5

cm

dia

met

er

• Li

ve c

ross

bea

m o

f 10

cm

dia

met

er a

nd

2

m lo

ng

• G

abio

n w

ire

Adh

atod

a va

sica

, Ipo

mea

fist

ulat

a,

Lant

ana

cam

ara,

Vite

x ne

gund

o, S

alix

spec

ies,

Gag

ruga

pin

nata

Sep

ium

insi

gne

• H

essi

an a

nd w

ater

to

keep

the

cut

ting

m

oist

unt

il pl

antin

g

• Po

inte

d pl

antin

g ba

rs o

r cr

owba

rs t

o

m

ake

hole

s fo

r pl

antin

g

Spec

ifica

tion

Cons

truc

tion

peri

od

• Sp

acin

g be

twee

n pa

lisad

es d

epen

ds o

n th

e st

eepn

ess

of t

he s

lope

: 2 m

inte

rval

for

sl

ope

less

tha

n 30Æ

slo

pe a

nd 1

m in

terv

al f

or 3

0Æ-

45Æ

slop

e.

• W

ithin

the

pal

isad

es li

nes,

spa

cing

bet

wee

n th

e cu

ttin

gs is

2 t

o 3

cm.

• D

urin

g do

rman

t (N

ovem

ber-

Janu

ary)

se

ason

if t

he s

ite is

moi

st.

• Ju

st b

efor

e m

onso

on if

the

site

is d

ry

(M

ay-J

une)

Pa

lisad

e


Refe

renc

es: D

OI,

1992

. DO

R, 1

999.

FA

O, 1

985,

ITEC

O, 1

990,

DSC

WM

200

4.

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(Sit

e fo

r ap

plic

atio

n)

• In

spec

t th

e ar

ea d

urin

g th

e fir

st r

ainy

sea

son.

Rep

air

and

stre

ngth

en a

ny e

xpos

ure

or b

reak

s of

the

st

akes

to

allo

w g

row

th o

f ve

geta

tion

to t

ake

plac

e.

• So

me

thin

ning

may

be

requ

ired

afte

r a

few

yea

rs.

• Si

te w

ith p

oorl

y dr

aine

d m

ater

ial

su

bjec

t to

hig

h ra

tes

of s

mal

l sca

le

sl

umpi

ng s

houl

d be

avo

ided

.

• M

ake

sure

cut

tings

do

not

dry

in t

he

su

n.

• Ca

n be

use

d on

a w

ide

rang

e of

site

s up

to

abo

ut 6

0Æ s

lope

. Eff

ectiv

e on

ste

ep

la

ndsl

ide

debr

is.

• G

ood

for

stee

p, n

arro

w g

ullie

s.


Titl

e: B

RUSH

LA

YERI

NG

Wha

t is

it?

A la

yer

of li

ve w

oody

cut

tings

pla

nted

in li

ne a

cros

s th

e sl

ope,

usu

ally

fol

low

ing

the

cont

our

Sket

chFu

ncti

onLi

mit

atio

n

Re

info

rces

the

slo

pe

Catc

hes

mat

eria

ls m

ovin

g do

wn

the

slop

e, a

nd h

elp

bio-

terr

acin

g

If an

gled

, hel

ps t

o dr

ain

out

wat

er

Cons

ider

able

dis

turb

ance

to

the

slop

e

Adv

anta

ges

Dis

adva

ntag

es

Prov

ides

a v

ery

stro

ng a

nd lo

w-c

ost

barr

ier

on lo

ose

debr

is s

lope

Sim

ple

and

easi

ly b

uilt

with

imm

edia

te e

ffec

t

In lo

ng t

erm

, a s

mal

l ter

race

will

for

m

Adv

entit

ious

roo

ting

guar

ante

es s

econ

dary

rei

nfor

cem

ent

Dig

ging

of

terr

aces

dis

turb

s th

e sl

ope

cons

ider

ably

Brus

h la

yeri

ng s

houl

d be

use

d on

slo

pes

cons

istin

g of

loos

e m

ater

ial

Plan

ting

ste

ps

Star

t 50

cm

fro

m t

he b

ase

of t

he s

lope

and

wor

k up

war

ds

Mar

k th

e co

ntou

r lin

es f

or t

erra

ce d

iggi

ng

Mak

e 50

– 1

00 c

m w

ide

terr

aces

with

an

incl

inat

ion

of a

t le

ast

10 –

20

% in

war

d

Lay

the

cutt

ings

cro

ssw

ise

at 5

to

10 c

m in

terv

al. P

lace

the

bra

nche

s cr

ossw

ise

on t

he t

erra

ces

to p

erm

it th

e us

e of

long

er

bran

ches

At

leas

t on

e bu

d an

d 1/

3 to

1/4

of

the

bran

ch s

houl

d ex

tend

ove

r th

e ed

ge o

f th

e te

rrac

e an

d 3/

4 in

side

Use

bra

nche

s (6

to

18 m

onth

s ol

d of

2 t

o 4

cm d

iam

eter

) of

diff

eren

t sp

ecie

s, o

f di

ffer

ent

ages

, and

dia

met

ers.

Thi

s al

low

s

grea

ter

chan

ces

of s

urvi

val a

nd p

rodu

ces

mix

ed v

eget

atio

n.

If po

ssib

le, t

ake

the

cutt

ing

the

sam

e da

y th

at t

hey

are

to b

e pl

ante

d.

Fill

the

low

er b

ench

with

the

mat

eria

l exc

avat

ed f

rom

the

abo

ve t

erra

ce a

nd c

ompa

ct it

rea

sona

bly

wel

l with

gen

tle

foot

pres

sure

.

Mat

eria

lsSp

ecie

s To

ols

Bran

ches

of

root

ing

plan

ts o

f di

ffer

ent

spec

ies

6 to

18

mon

ths

old,

2 t

o 4

cm d

iam

eter

, and

75 t

o 10

0 cm

long

Cut

the

bran

ches

at

righ

t an

gles

at

top

and

at

45Æ

at

bott

om

Adh

atod

a va

sica

, Ipo

mea

fistu

lata

, Lan

tana

cam

ara,

Vite

x

negu

ndo,

Sal

ix s

peci

es, G

agru

ga

pinn

ata,

Sep

ium

nsi

gne,

Erit

hrin

a

varie

gate

, Mor

us a

lba,

Dur

anth

a

repe

ns, J

atro

pha

curc

as

Hes

sian

and

wat

er t

o ke

ep t

he c

uttin

g

moi

st u

ntil

plan

ting

Shov

els

and

pick

axe

s to

mak

e th

e

slop

ing

terr

aces

for

pla

ntin

g

Line

str

ing

/ T

ape

(30

m)

Plan

ting

Peri

od

Spec

ifica

tion

sPl

anti

ng p

erio

d

Spac

ing

betw

een

brus

h la

yer

depe

nds

on t

he s

teep

ness

of

the

slop

e:

2 m

inte

rval

for

less

tha

n 30Æ

slo

pe a

nd 1

m in

terv

al f

or 3

0Æ -

45Æ

slop

e

Dur

ing

dorm

ant

seas

on if

the

site

is m

oist

z

Spac

ing

depe

nds

on t

he s

tabi

lity

of t

he s

oil m

ater

ial a

nd m

ay v

ary

from

2-5

m in

terv

al

Just

bef

ore

mon

soon

if t

he s

ite is

dry

(M

ay -

June

)

Bru

sh L

ayer

ing


Mai

nten

ance

Prec

auti

ons

Scop

e (S

ite

for

appl

icat

ion)

Beca

use

the

spac

ing

of p

lant

s in

bru

sh la

yerin

g is

ver

y de

nse,

ther

e is

unl

ikel

y to

be

a ne

ed f

or r

epla

cing

fai

lure

s

Insp

ect

the

area

dur

ing

the

first

rai

ny s

easo

n. R

epai

r an

d

stre

ngth

en a

ny b

reak

s of

the

sta

kes

to a

llow

gro

wth

of

the

vege

tatio

n to

tak

e pl

ace.

Som

e th

inni

ng o

f sh

rubs

may

be

requ

ired

afte

r fe

w y

ears

.

Ensu

re t

he li

nes

run

alon

g th

e co

ntou

rs a

nd d

o no

t co

ncen

trat

e ru

noff

.

Mak

e su

re t

hat

cutt

ings

are

not

allo

wed

to

dry

in t

he s

un.

Avo

id u

sing

thi

s te

chni

que

on p

oorl

y dr

aine

d ar

ea s

ubje

ct t

o sm

all

scal

e sl

umpi

ng.

Suita

ble

for

wet

slo

pes

or s

teep

and

roc

ky s

lope

s no

t

subj

ect

to s

lum

ping

Wid

e ra

nge

of s

ites

up t

o ab

out

45°

and

high

emba

nkm

ents

Effe

ctiv

e to

sta

biliz

e lo

ose

debr

is s

ites

and

fill s

lope

s

Effe

ctiv

e in

pre

vent

ing

shal

low

slid

ing

Refe

renc

es: D

OR,

199

9, D

OI,

1992

. FA

O, 1

985.

ITEC

O, 1

990,

DSC

WM

200

4.


Titl

e: W

ATT

LIN

GW

hat

is it

? W

attl

ing

is r

ows

of f

ence

mad

e ou

t of

veg

etat

ive

mat

eria

ls (

pref

erab

ly li

ve c

uttin

gs)

plac

ed a

cros

s th

e co

ntou

r of

the

slo

pe.

Sket

chFu

ncti

onLi

mit

atio

n

• • • • • • • • • • • •

• Ca

tche

s de

bris

mov

ing

dow

n th

e sl

ope

• Re

info

rces

the

slo

pe

• M

odifi

es t

he s

lope

• A

pplic

able

onl

y on

a s

lope

with

a li

mite

d vo

lum

e of

deb

ris

flo

w

• D

ange

r of

bre

akin

g be

caus

e of

fal

ling

rock

s

Adv

anta

ges

Dis

adva

ntag

es

• Fa

st a

nd s

impl

e pr

otec

tion

• La

bor

and

mat

eria

l int

ensi

ve

• Es

tabl

ishe

s a

mic

ro-s

ite f

or o

ther

pla

nts

• D

rivi

ng s

take

s lo

osen

s th

e so

il

Cons

truc

tion

ste

ps

• Pr

epar

e th

e si

te w

ell i

n ad

vanc

e of

pla

ntin

g. C

lear

all

loos

e m

ater

ial a

nd p

rotr

usio

n, a

nd fi

rmly

infil

l dep

ress

ions

.

• M

ark

on t

he s

lope

the

line

s w

here

wat

tle

fenc

es a

re t

o be

inst

alle

d to

ens

ure

that

the

line

s fo

llow

the

con

tour

.

• D

ig a

hol

e fo

r pl

acin

g st

akes

with

cro

wba

r or

aug

er. P

lace

1 m

long

sta

kes

at in

terv

als

of a

bout

1 m

alo

ng t

he li

nes;

and

pla

ce t

wo

50

cm

long

sta

kes

in b

etw

een

the

long

sta

kes.

Sta

kes

shou

ld p

rotr

ude

abou

t 20

- 3

0 cm

.

• D

ig o

ut a

gro

ove

alon

g th

e co

ntou

r be

twee

n th

e st

akes

; it

shou

ld b

e at

leas

t 15

cm

dee

p.

• Pl

ace

the

cutt

ings

with

the

ir lo

wer

end

s in

the

gro

ove,

ben

ding

the

m d

own

alon

g th

e lin

e of

the

fen

ce. W

eave

the

m in

and

out

be

twee

n th

e st

akes

. Fir

m t

he s

oil b

ack

into

the

gro

ove.

• Th

e br

ush

wea

ving

sho

uld

be a

lmos

t ho

rizo

ntal

ly a

bove

eac

h ot

her,

but

with

the

end

s fir

mly

pla

nted

in t

he s

oil.

• Fi

ll th

e so

il be

hind

the

wat

tles

for

the

pla

ntat

ion

of t

rees

, gra

ss s

eedl

ings

, and

cut

tings

.

Mat

eria

lsSp

ecie

s To

ols

• St

akes

1 m

long

, 8-1

0 cm

di

amet

er, a

nd 5

0 cm

long

, 6-8

cm

dia

met

er. S

harp

en a

ll st

akes

at

the

bot

tom

.

• W

oody

cut

tings

of

long

and

fle

xibl

e pl

ants

whi

ch r

oot

easi

ly

(m

ore

than

150

cm

long

and

3 –

5

cm d

iam

eter

)

• If

spro

utin

g m

ater

ials

are

not

av

aila

ble,

mat

eria

l lik

e ba

mbo

o

co

uld

be u

sed.

• Ju

te o

r co

ir st

ring

or

wir

e to

bin

d

• Li

ve s

tack

for

anc

hori

ng s

take

s: E

ryth

rina

arbo

resc

enes

, Sal

ix

sp

ecie

s, G

agru

ga p

inna

ta, P

opul

us, P

lum

eria

acu

min

ate,

Fi

cus

laco

r, S

epiu

m in

segn

e, e

tc.

• Bu

shes

, Shr

ubs:

Adh

atod

a va

sica

, Dur

anta

rep

ens,

Ipom

ea

fis

tula

ta, J

atro

pha

curc

as, S

alix

spe

cies

, Lan

tana

cam

ara,

Vi

tex

negu

ndo,

etc

.

• To

ols

to d

ig t

renc

h

• Cr

ow b

ar a

nd h

amm

er t

o dr

ive

st

akes

• H

essi

an a

nd w

ater

to

keep

the

cu

ttin

g m

oist

unt

il pl

antin

g

Spec

ifica

tion

Cons

truc

tion

per

iod

• Sp

acin

g be

twee

n lo

ng s

take

s 1

m

• A

vera

ge h

oriz

onta

l dis

tanc

e be

twee

n w

attl

ing

is 1

-2m

on

stee

p

sl

ope

• D

urin

g do

rman

t se

ason

if t

he s

ite is

moi

st

• Ju

st b

efor

e m

onso

on if

the

site

is d

ry (

May

, Jun

e)


Prec

auti

ons

Scop

e (S

ite

for

appl

icat

ion)

• A

void

spl

ittin

g th

e st

akes

by

plac

ing

a pi

ece

of s

tron

g w

ood

on

th

e to

p of

the

sta

ke w

hen

it is

bei

ng d

rive

n in

• U

sefu

l in

the

smal

l sha

llow

sho

rt le

ngth

slid

es

• In

est

ablis

hing

the

gul

ly h

eads

slo

pes

• In

com

bina

tion

with

oth

er m

easu

res

usef

ul f

or b

ank

prot

ectio

n

Mai

nten

ance

• Si

nce

the

spac

ing

of p

lant

s in

wat

tle

fenc

es is

ver

y de

nse,

the

re is

unl

ikel

y to

be

a ne

ed f

or r

epla

cing

fai

lure

s. H

owev

er, r

egul

ar

pr

otec

tion

from

gra

zing

and

hum

an in

terf

eren

ce is

nee

ded.

• In

spec

t th

e ar

ea d

urin

g th

e fir

st r

ainy

sea

son.

Rep

air

and

stre

ngth

en a

ny b

reak

s of

the

sta

kes

gro

wth

of

to a

llow

veg

etat

ion

to t

ake

pl

ace.

• So

me

thin

ning

of

shru

bs m

ay b

e re

quir

ed a

fter

few

yea

rs.

Refe

renc

es: D

OI,

1992

, DO

R, 1

999.

DSC

WM

, 198

3, F

AO

, 198

5, D

SCW

M 2

004.


© WWF Nepal, Hariyo Ban Program/ Nabin Baral

Titl

e: V

EGET

ATI

VE R

IP-R

AP

Wha

t is

it?

Ston

e pi

tchi

ng f

or s

urfa

ce p

rote

ctio

n w

ith m

ainl

y gr

ass

inte

r-pl

ante

d be

twee

n th

e st

ones

.

Func

tion

Lim

itat

ion

Rein

forc

es a

nd a

rmor

s th

e sl

ope

agai

nst

eros

ion.

Allo

ws

seep

age

to fl

ow o

ut b

etw

een

the

ston

es.

Lim

ited

cons

truc

tion

heig

ht, l

engt

h, a

nd s

lope

Cann

ot b

e us

ed in

gul

ly b

eds

with

cop

ious

deb

ris

flow

Adv

anta

ges

Dis

adva

ntag

es

Ston

es a

re n

ot d

islo

dged

onc

e th

e ve

geta

tion

is e

stab

lishe

d.

Goo

d dr

aina

ge t

hrou

gh w

all b

y th

e pl

ants

Rege

nera

tion

is o

bstr

ucte

d by

the

sto

nes

Rela

tivel

y ex

pens

ive

to c

arry

out

in la

rge

scal

e

Cons

truc

tion

ste

ps

Reta

inin

g or

toe

wal

l as

terr

ace

rais

er

• Sm

ooth

the

slo

pe

• Co

nstr

uct

the

toe

wal

l nor

mal

ly

• M

ake

sure

the

re is

ple

nty

of s

oil i

n ba

ck o

f th

e w

all

• Pr

ovid

e a

foun

datio

n as

nec

essa

ry

• Fi

ll th

e vo

ids

with

soi

l and

sm

all s

tone

s

• W

ait

until

the

rai

ns f

or p

lant

ing

cutt

ings

s or

see

ds

• Ta

ke c

are

that

the

bar

k or

see

d co

at is

not

dam

aged

.

Gul

ly H

ead

• Re

shap

e th

e gu

lly h

ead

to a

n ev

en s

urfa

ce

• O

ther

ste

ps s

ame

as g

ully

bed

s

• Pr

ovid

e an

apr

on a

t th

e bo

ttom

to

prev

ent

scou

ring

• Pr

otec

t to

e of

the

gul

ly h

ead

with

a c

ylin

dric

al m

esh

wir

e fil

led

w

ith s

tone

s or

gra

vel

Gul

ly b

edSt

ream

ban

k

• Cl

ean

the

gully

floo

r co

mpl

etel

y of

all

debr

is, e

xcav

ate,

and

sha

pe

un

til a

firm

bas

e is

exp

osed

or

com

pact

the

soi

l.

• Pr

ovid

e fo

unda

tion

as n

eces

sary

• La

y ou

t st

ones

kee

ping

the

flat

test

sid

es o

n th

e su

rfac

e

• Re

duce

gap

s to

a m

inim

um a

nd p

ack

all v

oids

with

soi

l and

sm

all

st

ones

• Th

e st

one

pitc

hing

sho

uld

have

con

cave

cro

ss-s

ectio

n fo

r w

ater

flo

w a

nd t

o pr

even

t sc

ouri

ng a

t th

e si

des

• Th

ickn

ess

of r

ipra

p sh

ould

be

a m

inim

um o

f 15

cm t

hick

• Pl

ace

the

heav

iest

roc

ks a

long

the

bot

tom

.

• Ex

tend

the

pitc

hing

2 t

o 3m

bey

ond

the

area

of

activ

e er

osio

n

• En

tren

ch t

he b

otto

m r

ow o

f st

one

into

the

str

eam

bed

to p

reve

nt

un

derc

uttin

g.

• pl

ant

cutt

ings

, slip

s, o

r se

eds

of g

rass

or

brus

h at

the

sta

rt o

f th

e

ra

in

• Id

eally

, sm

alle

r gr

asse

s sh

ould

be

plan

ted

in t

he m

ain

chan

nel,

w

ith la

rger

gra

sses

or

brus

hes

alon

g si

des

• Tr

im t

he a

rea

to a

n ev

en s

urfa

ce. R

emov

e al

l fre

e lo

ose

debr

is.

Co

mpa

ct t

he s

oil.

It s

houl

d no

t ha

ve a

ny p

ocke

ts o

f fin

er

m

ater

ials

, whi

ch w

ould

flus

h ou

t an

d w

eake

n th

e st

ruct

ure.

• Pl

ace

a hi

ghly

per

mea

ble

and

appr

opri

atel

y si

zed

geo-

text

ile

fil

ter

fabr

ic o

n th

e pr

epar

ed s

lope

to

prot

ect

the

soil

from

w

ashi

ng. T

ake

care

not

to

tear

the

filt

er f

abri

c du

ring

inst

alla

tion.

• Pl

ace

a la

yer

(15

cm m

inim

um)

of g

rave

l or

smal

l roc

k on

the

ge

o-te

xtile

filt

er f

abri

c. T

he u

nder

layi

ng g

rave

l or

ston

e ne

ed

to

be

size

d ap

prop

riat

ely

so it

will

not

was

h ou

t th

roug

h th

e

ga

ps b

etw

een

the

ripr

ap s

tone

s.

• Bu

ild t

he s

tone

pitc

hing

car

eful

ly, fi

ttin

g th

e st

ones

tog

ethe

r

fir

mly

as

if it

is a

dry

mas

onry

wal

l. St

ones

sho

uld

be

pe

rpen

dicu

lar

to t

he s

lope

, with

the

mai

n po

int

or n

arro

w s

ide

do

wn.

• Th

e th

ickn

ess

of t

he s

tone

pitc

hing

sho

uld

be 1

.5 t

imes

the

th

ickn

ess

of t

he la

rges

t st

one,

on

top

of t

he g

rave

l. Th

e he

avie

st

ro

cks

shou

ld b

e pl

aced

alo

ng t

he b

otto

m.

• Ex

tend

the

rip

rap

2 to

3 m

on

eith

er s

ide

of t

he a

ctiv

e er

osio

n

ar

ea t

o pr

even

t fu

rthe

r er

osio

n be

yond

the

str

uctu

re

Vege

tati

ve r

ip-r

ap a

t To

e w

all,

Wei

ldt,

197

6

Veg

etat

ive

rip-

rap

on g

ully

bed

Ripr

ap in

gul

ly b

ed (

How

ell,

et a

l. 19

91)

Vege

tati

ve r

ip-r

ap


• W

hen

only

rip

rap

is b

eing

use

d fo

r ba

nk s

tabi

lizat

ion,

the

top

of

th

e ri

prap

sho

uld

exte

nd 1

m a

bove

the

ord

inar

y hi

gh w

ater

m

ark.

• En

tren

ch t

he b

otto

m r

ow o

f st

one

into

the

gro

und

to p

reve

nt

un

derc

uttin

g.

• D

esig

n ri

prap

str

uctu

res

for

stre

am b

ank

stab

iliza

tion

to b

e st

able

fo

r fu

ll flo

ws.

•

Mat

eria

lsSp

ecie

s To

ols

• A

ngul

ar o

r irr

egul

ar e

dges

on

hard

sto

nes

for

go

od in

terl

ocki

ng.

• Lo

ng s

trai

ght

stem

s or

cut

tings

or

seed

s of

su

itabl

e sh

rubs

(bu

t no

t of

larg

e tr

ees)

, tha

t

ro

ot e

asily

or

gras

s sl

ips

• G

ener

ally

, gra

ss s

eeds

are

not

use

d

Som

e sh

rubs

and

Bus

hes

to p

lant

on

ripr

ap:

Adh

atod

a va

sica

, Dur

anth

a re

pens

,

Euph

orbi

a ro

ylea

na, J

atro

pha

curc

as, V

itex

negu

ndo,

Aca

cia

penn

ata,

But

ea m

inor

Som

e gr

asse

s to

pla

nt a

mon

g ri

prap

in

gulli

es (

Use

d in

Nep

al):

Pog

onat

heru

m

pani

cum

; Cyn

odon

dac

tylo

n; T

hysa

nola

ena

max

ima;

Cym

bopo

gon

mic

roth

eca

• Sh

ovel

s, h

amm

er a

nd p

ick

axes

to

pitc

h

st

ones

,

• Sh

ort

plan

ting

bars

• H

essi

an a

nd w

ater

to

keep

the

pla

ntin

g

st

ock

moi

st u

ntil

plan

ting

Spec

ifica

tion

Cons

truc

tion

per

iod

• To

e w

all u

p to

2 m

hei

ght

and

laid

bac

k at

an

angl

e of

abo

ut 6

0Æ

• La

yout

of

the

ripra

p sh

ould

be

conc

ave

to c

once

ntra

te w

ater

in t

he m

iddl

e

• If

plan

ts c

an b

e gr

own

betw

een

all s

tone

s, it

wou

ld b

e be

nefic

ial

• Ri

prap

sto

ne w

all c

an b

e bu

ilt a

t any

tim

e

• Pl

ant

cutt

ing

duri

ng d

orm

ant

and

se

edlin

g be

fore

mon

soon

sea

son

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(Sit

e fo

r ap

plic

atio

n)

• In

spec

t im

med

iate

ly a

fter

the

firs

t an

d ev

ery

la

rge

stor

m

• Re

pair

any

disp

lace

d ri

prap

• Re

gula

r cu

ttin

g of

gra

ss a

nd p

runi

ng o

f sh

rubs

/

bush

es is

ess

entia

l to

prom

ote

root

sys

tem

s

an

d to

avo

id fl

ow o

bstr

uctio

n

• So

me

thin

ning

of

shru

bs m

ay b

e re

quir

ed a

fter

fe

w y

ears

.

• A

void

rou

nd s

tone

s

• Pl

antin

g m

ust

be d

eep

enou

gh t

o av

oid

dr

ying

up

• O

nly

2-3

cm o

f cu

ttin

gs s

houl

d be

ex

pose

d ou

tsid

e th

e w

all

• Pl

antin

g sh

ould

not

dam

age

the

bark

or

se

ed c

oat

• Lo

w s

lope

toe

wal

ls o

f up

to

2 m

in

he

ight

• G

ully

floo

rs w

ith a

max

imum

slo

pe o

f

45Æ

/ R

oad

drai

nage

• G

ully

hea

d af

ter

resh

apin

g

• Ro

ad o

r tr

ail s

lope

s

• St

ream

or

rive

r ba

nk w

ith m

ediu

m fl

ow

Rip-

rap,

Wei

ldt,

197

6

Vege

tati

ve r

ip-r

ap o

f G

ully

Hea

d W

eild

t, 1

976

Stone rip-rap on slope

Stone rip-rap on

drainage lines

Refe

renc

es: -

BIW

MP,

200

3, D

OI,

1992

., D

OR,

199

9, IT

ECO

, 199

0, S

thap

it, K

. M.,

1998

. Wei

dlt,

H.J.

(co

mpi

led)

, 197

6. O

hio

Dep

artm

ent

of N

atur

al R

esou

rces

. Rip

rap

Reve

tmen

t. w

w.o

hiod

nr.c

om/

wat

er/p

ubs/

fs_s

t/st

fs16

.htm

, DSC

WM

200

4.


Titl

e: W

ATE

RWA

YSW

hat

is it

? W

ater

cour

se m

ade

for

the

safe

dis

posa

l of

runo

ff w

ater

or

dive

rtin

g w

ater

out

of

an a

ctiv

e la

ndsl

ide

or g

ully

into

a s

afe

outl

et

Gra

ss w

ater

way

sG

rass

wat

erw

ays

with

dro

psSt

one

lined

wat

erw

ays

Wat

erw

ays

plan

ted

with

low

and

rhiz

ome

type

gras

s. G

ener

ally

mad

e in

par

abol

ic s

hape

.

Gra

ss w

ater

way

s w

ith s

mal

l dro

ps k

eep

the

flow

from

sco

urin

g th

e be

d.

Wat

erco

urse

line

d w

ith s

tone

to

prot

ect

the

bed

from

ero

sion

.

A w

ater

way

sho

uld

not

be u

sed

until

the

gras

s co

ver

is p

rope

rly

esta

blis

hed.

Dro

p st

ruct

ures

pre

ferr

ed t

o be

bel

ow 1

m h

eigh

t

but

neve

r ta

ller

than

1.8

m.

15-3

0 cm

dia

met

er s

tone

s sh

ould

be

keye

d in

the

gro

und

Func

tion

Lim

itat

ion

of g

rass

wat

erw

ays

• Sa

fely

dis

pose

of

runo

ff

• D

rain

exc

ess

runo

ff t

o a

safe

and

sui

tabl

e si

te.

• Pr

even

t su

rfac

e ru

noff

fro

m e

nter

ing

the

area

to

be

st

abili

zed

(Gul

lies

and

land

slid

es).

• Ca

n on

ly b

e us

ed f

or s

mal

l am

ount

of

runo

ff.

• Ca

nnot

be

used

whe

re t

here

is a

con

tinuo

us fl

ow o

f w

ater

.

• Ca

nnot

be

used

unt

il th

e gr

ass

cove

r is

pro

perl

y es

tabl

ishe

d.

Adv

anta

ges

Dis

adva

ntag

es

• Lo

w c

ost

• Ea

sy t

o m

aint

ain

• Fr

agile

and

eas

ily d

estr

oyed

if n

ot p

rope

rly

mai

ntai

ned

and

prot

ecte

d.

Cons

truc

tion

ste

ps

• Cl

ear

the

site

. Mar

k th

e lin

es w

ith s

trin

gs w

here

wat

erw

ays

are

to b

e co

nstr

ucte

d. E

nsur

e th

at s

lope

of

the

alig

nmen

t pr

oper

ly s

o th

at t

he

ru

noff

spe

ed is

wel

l bel

ow t

he s

cour

ing

velo

city

.

• D

ig t

he w

ater

way

s gi

ving

uni

form

sha

pe (

cros

s-se

ctio

n) a

nd s

lope

. See

des

ign

step

s fo

r ca

lcul

atio

n of

the

siz

e an

d sl

ope

of t

he w

ater

way

s

fo

r di

ffer

ent

runo

ff.

• Pl

ant

the

gras

s pr

efer

ably

loca

lly a

vaila

ble,

rhi

zom

e, o

r so

d fo

rmin

g gr

ass.

If s

eedi

ng is

don

e, p

lant

ing

of s

eed

shou

ld b

e do

ne w

ith s

hallo

w

di

tchi

ng a

nd m

ulch

ing

at t

he b

egin

ning

of

the

rain

y se

ason

. Pro

vide

sod

ding

at

the

junc

tion

of t

he e

arth

and

the

str

uctu

re t

o av

oid

wat

er

tu

nnel

ing.

• Co

nstr

uct

loos

e st

one

drop

str

uctu

re s

o th

at r

unof

f sp

eed

is w

ell b

elow

the

sco

urin

g ve

loci

ty. T

he h

eigh

t of

the

loos

e st

one

drop

str

uctu

re

sh

ould

not

be

mor

e th

an ½

met

er.

• Pr

ovid

e su

ffici

ent

and

stro

ng f

ound

atio

n an

d ap

ron

for

the

drop

str

uctu

re.

• Pr

ovid

e w

ing

wal

l to

dire

ct fl

ow t

o th

e w

eir

of t

he s

truc

ture

.

• A

fter

the

str

uctu

re is

bui

lt, t

ram

p ea

rth

solid

ly b

ehin

d an

d ar

ound

it t

o pr

even

t cr

acki

ng.

Des

igni

ng w

ater

way

s

• Su

rvey

the

wat

ersh

ed t

o es

timat

e th

e pe

ak r

unof

f. Be

st t

o us

e Ra

tiona

l For

mul

a fo

r ru

noff

est

imat

ion

• Ru

noff

in c

umec

s, Q

= D

imen

sion

less

run

off

coef

ficie

nt (

c) *

Rai

nfal

l int

ensi

ty (

mm

/hr

) fo

r de

sign

fre

quen

cy f

or t

ime

of c

once

ntra

tion

* A

rea

in

ha

(A)

• Ta

ke p

erm

issi

ble

velo

city

of

1.2

to 1

.8 m

/sec

for

den

se g

rass

dep

endi

ng u

pon

the

dens

ity

• Co

mpu

te a

ppro

xim

ate

cros

s-se

ctio

nal a

rea

of t

he c

hann

el t

o ca

rry

out

desi

gn r

unof

f : Q

= A

(A

rea

of w

ater

way

s) *

V (

Perm

issi

ble

velo

city

)

• A

rea

calc

ulat

ion

for

para

bolic

cro

ss s

ectio

n: A

= (

2/3)

*T*d

, W

here

, T =

Top

wid

th, d

= d

epth

of

para

bolic

sec

tion

at t

he m

iddl

e

• Co

mpu

te t

he w

ette

d pe

rim

eter

for

the

cro

ss s

ectio

n, P

= T

+ (

8/3)

* (

d2 /T)

Gra

ss w

ater

way

s

Gra

ss w

ater

way

s

wit

h dr

ops

Ston

e lin

ed

wat

erw

ays

Para

bolic

Cro

ss S

ecti

on o

f W

ater

way

s


• Co

mpu

te t

he h

ydra

ulic

rad

ius

for

the

cros

s se

ctio

n, R

= A

/ P

• Co

mpu

te t

he w

ater

vel

ocity

in t

he w

ater

way

s us

ing

Man

ning

’s F

orm

ula,

V =

(R2/

3 *

S1/2 )

/n

,

W

here

,

•

S =

wat

er S

urfa

ce s

lope

cor

resp

ondi

ng t

o hi

gh w

ater

leve

l = It

is t

he r

atio

of

vert

ical

dro

p to

the

leng

th o

f th

e st

ream

.

•

N =

rou

ghne

ss c

oeffi

cien

t, 0

.035

-0.0

45 (

0.04

) fo

r lo

osel

y gr

asse

s an

d 0.

040-

0.06

0 (0

.05)

for

den

sely

gra

ssed

wat

erw

ays.

• If

calc

ulat

ed V

is b

elow

the

per

mis

sibl

e ve

loci

ty, t

he d

esig

n cr

oss

sect

ion

is s

afe

from

bed

sco

urin

g or

ero

sion

• Ca

lcul

ate

the

flow

the

des

ign

cana

l acc

omm

odat

e, Q

= A

(Cr

oss

sect

ion

Are

a of

des

ign

wat

erw

ays)

* V

(Ca

lcul

ated

vel

ocity

usi

ng M

anni

ng’s

Fo

rmul

a

• If

calc

ulat

ed fl

ow t

hat

can

be a

ccom

mod

ated

by

the

wat

erw

ay is

mor

e th

an e

xpec

ted

max

imum

run

off,

the

des

ign

sect

ion

of t

he w

ater

way

is

saf

e/go

od.

Mat

eria

lsSp

ecie

sTo

ols

• Lo

cally

ava

ilabl

e so

d-fo

rmin

g ty

pe g

rass

.

• H

ead

size

d st

ones

Cyno

n da

ctyl

on, P

aspa

lum

and

Cen

tiped

e gr

ass,

etc.

Shor

t pl

antin

g ba

rs

• Li

ne s

trin

g /

Tap

e (3

0 m

eter

s)

• Sh

ovel

s an

d Pi

ck a

xes

to m

ake

the

w

ater

way

s

• M

eans

of

tran

spor

ting

plan

ts t

o si

te

• H

essi

an a

nd w

ater

to

keep

the

pla

ntin

g

st

ock

moi

st u

ntil

plan

ting

Spec

ifica

tion

Cons

truc

tion

per

iod

• Cr

oss-

sect

ion

of t

he w

ater

way

sho

uld

be s

hallo

w a

nd in

the

par

abol

ic s

hape

.

• G

roun

d sl

ope

not

mor

e th

an 2

0 %

,

• Th

e gr

ass

wat

erw

ays

shou

ld n

ot b

e lo

nger

tha

n 30

m;

• Pr

ovid

e dr

op s

truc

ture

s if

long

er w

ater

way

s.

• D

rop

stru

ctur

e no

t m

ore

than

50

cm h

igh.

Use

big

flat

sto

nes

in c

onst

ruct

ion.

• M

aint

ain

3% s

lope

bet

wee

n tw

o dr

op s

truc

ture

s.

• Si

de w

alls

for

the

dro

p st

ruct

ure

mus

t be

hig

h en

ough

to

dire

ct t

he fl

ow t

o th

e w

eir.

• D

urin

g do

rman

t se

ason

if t

he s

ite is

m

oist

.

• Ju

st b

efor

e ra

in if

the

site

is d

ry.

• •

Mai

nten

ance

Prec

auti

ons

Scop

e (S

ite

for

appl

icat

ion)

• In

spec

t th

e w

ater

way

s re

gula

rly

(mai

nly

du

ring

the

first

rai

ny s

easo

n). R

epai

r an

y

da

mag

e (s

uch

as b

reak

s, t

unne

ling)

bef

ore

it

gets

wor

se.

• Re

mov

e br

ush

or la

rge

wee

ds b

efor

e th

ey

w

eake

n th

e gr

ass.

• Re

gula

r gr

ass

cutt

ing

• Sh

arp

turn

s an

d su

dden

fal

ls s

houl

d be

avo

ided

un

less

wat

er c

olle

ctin

g ba

sin

or d

rop

stru

ctur

e

is

pla

nned

.

• Th

e w

ater

mus

t go

ove

r th

e st

ruct

ures

and

not

go

aro

und

them

.

• Th

e w

ater

way

s sh

ould

not

be

used

suc

h as

pa

ths.

• Fa

rm la

nds

• D

egra

ded

area


Div

ersi

on w

ater

way

s: C

onst

ruct

to

dire

ct r

un-o

ff

away

fro

m g

ully

hea

ds

• W

ater

way

s m

ust

be a

t le

ast

at a

dis

tanc

e tw

ice

th

e w

idth

of

the

gully

/ la

ndsl

ide

from

the

gul

ly

/

land

slid

e he

ad.

• W

ater

way

s si

ze m

ust

be la

rge

to a

ccom

mod

ate

m

axim

um r

unof

f.

• Ta

ke p

reca

utio

ns t

o sa

fely

dis

pose

of

the

di

vert

ed r

unof

f an

d no

t to

cre

ate

a ne

w g

ully

.

Den

sely

Gra

ssed

Wat

erw

ays

Tabl

e: S

ize

of c

atch

dra

ins

(cas

es)

Para

bolic

II

IIII

IIIIII

IVIV

VV

VIVI

VII

VII

VIII

VIII

IXIX

XX

XIXI

XII

XII

XIII

XIII

XIV

XIV

Qm

ax in

cum

ecs

0.10

0.10

0.15

0.15

0.20

0.20

0.25

0.25

0.30

0.30

0.35

0.35

0.40

0.40

0.45

0.45

0.50

0.50

0.62

0.62

0.75

0.75

0.80

0.80

0.87

0.87

0.99

0.99

t =

Top

wid

th in

m.

0.60

0.60

0.60

0.60

0.60

0.60

0.80

0.80

0.80

0.80

0.80

0.80

0.90

0.90

1.00

1.00

1.00

1.00

1.20

1.20

1.20

1.20

1.20

1.20

1.25

1.25

1.25

1.25

d =

Dep

th in

m.

0.30

0.30

0.30

0.30

0.40

0.40

0.40

0.40

0.40

0.40

0.50

0.50

0.50

0.50

0.60

0.60

0.60

0.60

0.70

0.70

0.70

0.70

0.70

0.70

0.80

0.80

0.80

0.80

s =

Cha

nnel

slo

pe0.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

080.

040.

08

Refe

renc

es:-

CSW

CS, 1

987.

DO

R, 1

999.

FA

O, 1

977.

Sth

apit,

K. M

., 19

98, D

SCW

M 2

004.


Titl

e: G

AB

ION

WIR

E B

OLS

TER

Wha

t is

it?

A g

abio

n tu

be fi

lled

with

sto

ne a

nd p

lace

d in

sha

llow

tre

nche

s ac

ross

in t

he s

lope

Func

tion

Lim

itat

ion

Prev

ent

surf

ace

scou

ring

and

gul

lyin

g

Prov

ide

supp

ort

to t

he s

hallo

w s

urfa

ce s

lippi

ng

Expe

nsiv

e co

mpa

red

to b

io-e

ngin

eeri

ng t

echn

ique

s

Adv

anta

ges

Dis

adva

ntag

es

Form

s a

stro

ng a

nd lo

ng la

stin

g st

ruct

ure

to a

rmor

a

slop

e su

rfac

e ag

ains

t gu

lly e

rosi

on.

If it

fails

it p

ulls

the

soi

l sur

face

aff

ectin

g ar

ea o

f its

appl

icat

ion.

Act

s as

sub

-sur

face

dra

inag

e if

plac

es in

her

ring

bone

patt

ern.

Dig

ging

of

tren

ches

dis

turb

s th

e so

il in

ste

ep s

lope

s.

Cont

our

wir

e bo

lste

rH

erri

ngbo

ne w

ire

bols

ter

Pl

ace

bols

ters

alo

ng a

con

tour

mai

nly

to r

educ

e gu

lly

eros

ion

and

stab

ilize

the

slo

pe. P

lace

on

wel

l-dr

aine

d

slop

es.

Plac

e bo

lste

rs in

a h

erri

ngbo

ne s

tyle

mai

nly

to r

educ

e

surf

ace

eros

ion

and

drai

n th

e ar

ea. P

lace

on

poor

ly

drai

ned

slop

es.

Co

nstr

ucti

on s

teps

Cons

truc

tion

ste

ps

Trim

the

are

a to

an

even

slo

pe w

ith n

o pr

otru

sion

s an

d

depr

essi

ons

Star

ting

from

the

bot

tom

of

the

slop

e, m

ark

out

a

cont

our

line

acro

ss t

he s

lope

Dig

a t

renc

h al

ong

the

line,

abo

ut 3

0-40

cm

wid

e an

d

30 -

40cm

dee

p (F

igur

e a)

Lay

a ga

bion

bol

ster

pan

el le

ngth

wis

e al

ong

the

tren

ch

(Fig

ure

b). E

nsur

e th

e ed

ge o

f th

e ga

bion

on

the

low

er

side

is in

line

with

low

er e

dge

of t

he t

renc

h.

Fill

the

bols

ter

with

sto

nes

larg

er t

han

the

mes

h si

ze.

Fold

the

upp

er e

dge

of t

he p

anel

ove

r th

e st

ones

and

join

it t

o th

e lo

wer

pan

el e

dge

(Fig

ure

c).

Leav

e a

10 c

m fl

ap f

rom

the

upp

er e

dge

exte

ndin

g ov

er

the

low

er e

dge.

Join

abu

ttin

g bo

lste

rs a

cros

s th

e sl

ope

into

con

tinuo

us

lines

; clo

se t

he e

xtre

me

ends

with

wir

e;

Star

ting

from

the

top

, bac

kfill

the

mat

eria

ls a

roun

d th

e

bols

ters

, com

pact

it a

nd c

lean

aw

ay d

ebri

s (F

igur

e d)

Trim

the

are

a to

an

even

slo

pe w

ith n

o pr

otru

sion

s an

d

depr

essi

ons;

Star

ting

from

the

bot

tom

of

the

slop

e, m

ark

out

the

lines

for

the

bol

ster

s; t

here

sho

uld

be o

ne v

ertic

al li

ne

and

slop

ing

lines

join

ing

vert

ical

line

mak

ing

an a

ngle

of 4

5º w

ith e

ach

line

abou

t 5

met

ers

long

.

Dig

a t

renc

h al

ong

the

line,

abo

ut 3

0-40

cm

wid

e an

d

40 -

60cm

dee

p;

Lay

a sh

eet

of b

lack

pol

ythe

ne a

long

the

bot

tom

and

low

er s

ide;

but

not

the

upp

er s

ide

of t

he t

renc

h.

Lay

the

gabi

on b

olst

er p

anel

s le

ngth

way

s in

the

tren

ches

. Ens

ure

the

edge

of

the

gabi

on o

n th

e lo

wer

side

is in

line

with

low

er e

dge

of t

he t

renc

h.

Fill

the

bols

ter

with

sto

nes

larg

er t

han

the

mes

s si

ze.

Fold

the

upp

er e

dge

of t

he p

anel

ove

r th

e st

ones

and

join

it t

o th

e lo

wer

pan

el e

dge;

the

sla

ntin

g lin

es a

t th

e

end

are

clos

ed.

Repe

at u

ntil

all s

lant

ing

lines

mee

t th

e ve

rtic

al li

ne.

Onc

e th

e sl

antin

g lin

es a

re c

ompl

ete,

dig

a v

ertic

al

tren

ch s

trai

ght

dow

n th

e sl

ope

and

inst

all a

ver

tical

bols

ter

to c

olle

ct w

ater

fro

m t

he b

otto

m.

Ben

d th

e to

p fl

ap o

ver.

Dri

ve a

pie

ce o

f st

eel b

ar in

to t

he

grou

nd im

med

iate

ly b

elow

the

com

plet

ed b

olst

ers.

Fill

the

pane

l wit

h st

one.

Lay

a bo

lste

r pa

nel

into

the

tre

nch.

Exca

vate

a t

renc

h.


Dri

ve 1

met

er lo

ng s

teel

bar

s, a

ngle

s, o

r sp

rout

ing

pole

s

into

the

gro

und

at r

ight

-ang

le t

o th

e sl

ope

ever

y 2

met

ers

alon

g th

e bo

lste

rs. P

ositi

on t

hem

imm

edia

tely

belo

w a

nd t

ouch

ing

the

bols

ters

, and

dri

ve t

hem

in

far

enou

gh s

o th

at t

hey

cann

ot b

e pu

lled

out

by h

and.

(Fig

ure

e).

Tie

the

vert

ical

bol

ster

with

sla

ntin

g bo

lste

rs.

Back

fill t

he m

ater

ials

aro

und

the

bols

ters

, com

pact

it

and

clea

n aw

ay d

ebri

s.

Dri

ve 1

met

er lo

ng s

teel

bar

s, a

ngle

s, o

r sp

rout

ing

pole

s in

to t

he g

roun

d at

rig

ht-a

ngle

to

the

slop

e ev

ery

2 m

eter

s al

ong

the

bols

ters

. Pos

ition

the

m im

med

iate

ly

belo

w a

nd t

ouch

ing

the

bols

ters

, and

dri

ve t

hem

in f

ar

enou

gh s

o th

at t

hey

cann

ot b

e pu

lled

out

by h

and.

Impl

emen

t bi

o-en

gine

erin

g w

orks

thr

ough

out

the

site

.

Mat

eria

lsSp

ecie

sTo

ols

• G

alva

nize

d ga

bion

she

et 1

0cm

m

esh

of r

equi

red

leng

th.

• A

ngul

ar s

tone

s fo

r co

ntou

r an

d

ro

unde

d st

ones

for

her

ring

bone

bo

lste

r of

mor

e th

an 1

0 cm

di

amet

er.

• 16

mm

iron

rod

s of

2m

long

iron

ro

ds /

angl

es

• 8-

10 c

m d

iam

eter

spr

outin

g po

les.

Spro

utin

g su

ch a

s Sa

lix s

peci

es,

Popu

lus,

Vite

x ne

gund

o G

agru

ga

pinn

ata,

Sep

ium

inse

gne

etc.

• To

ols

for

digg

ing

tren

ches

and

for

w

orki

ng w

ith g

abio

n w

ire;

• Sl

edge

ham

mer

s;

• Fo

r he

rrin

gbon

e bo

lste

r, t

hick

(2

0 ga

uge)

bla

ck p

olyt

hene

she

et.

•

Spec

ifica

tion

Cons

truc

tion

per

iod

• Pl

ace

bols

ters

at

vary

ing

inte

rval

s of

5 –

10

met

ers.

Th

e st

eepe

r th

e sl

ope,

the

clo

ser

the

bols

ters

sho

uld

be

inst

alle

d.

• Co

ntou

r bol

ster

use

d ro

unde

d ga

bion

of 3

0 - 4

0

cm

dia

met

er, w

here

as h

errin

gbon

e bo

lste

r use

d

re

ctan

gula

r gab

ion

box

30 to

40

wid

e -4

0 to

60

deep

cm

.

• Pr

efer

ably

dur

ing

dry

peri

od f

or in

stal

ling

the

bols

ters

.

• A

t th

e st

art

of t

he r

ain

afte

r so

il is

moi

st f

or

ve

geta

tion

to g

row

for

bio

-eng

inee

ring

wor

ks.

Mai

nten

ance

Pr

ecau

tion

sSc

ope

(Sit

e fo

r ap

plic

atio

n)

• O

peni

ng o

f th

e ga

bion

tub

e sh

ould

be

regu

larl

y ch

ecke

d af

ter

ever

y ra

in

an

d cl

osed

imm

edia

tely

• St

one

dent

ition

in a

ny r

ills

deve

lope

d be

twee

n th

e bo

lste

rs

• A

ny r

ill d

evel

oped

bel

ow t

he t

ube

mus

t be

clo

sed.

• La

ying

of

thic

k bl

ack

poly

then

e sh

eet

alon

g th

e

bo

ttom

and

low

er s

ide,

but

not

the

upp

er s

ide

of t

he

tr

ench

is e

ssen

tial i

n ca

se o

f he

rrin

gbon

e bo

lste

r.

• M

ust

avoi

d ri

ll fo

rmat

ion

betw

een

cont

our

bols

ters

.

• O

n m

ost

long

, exp

osed

slo

pes

betw

een

35º

to 5

0º

w

here

the

re is

a d

ange

r of

sco

urin

g or

gul

lyin

g on

th

e su

rfac

e.

• Co

ntou

r bo

lste

r is

use

d on

wel

l-dr

aine

d sl

ope

and

he

rrin

gbon

e bo

lste

rs a

re u

sed

on p

oorl

y dr

aine

d

sl

opes

with

a r

isk

of s

lum

ping

.

Cont

our

Bol

ster

Her

ring

bone

Bol

ster

Refe

renc

es: H

owel

l, et

. al.,

199

1.


Titl

e: R

ETA

ININ

G W

ALL

Wha

t is

it?

A r

etai

ning

wal

l is

a w

all b

uilt

to

resi

st t

he la

tera

l pre

ssur

e of

the

ear

th b

ehin

d it.

Func

tion

• W

ithst

ands

late

ral e

arth

pre

ssur

es

• Su

ppor

ts t

he e

arth

or

fill m

ater

ial o

r cu

t ea

rth

slop

es a

nd

• Su

ppor

t m

ount

ains

ide

slop

es f

or r

oad,

irri

gatio

n ca

nal,

and

othe

r in

fras

truc

ture

con

stru

ctio

n

• Pr

even

ts t

he t

oe c

uttin

g

• Pr

even

ts b

ank

eros

ion

Type

bas

ed o

n m

ater

ials

Crib

wal

l (B

ambo

o/W

oode

n)Lo

ose

ston

eG

abio

nM

ason

ry /

Con

cret

e

Gen

eral

cha

ract

eris

tics

• M

ade

of w

oode

n po

les

or b

ambo

o

an

d br

ush.

• Th

ey a

re c

heap

and

can

be

mad

e

w

ith lo

cally

ava

ilabl

e m

ater

ials

.

• M

ade

of lo

ose

ston

e

• St

abili

ty a

nd s

tren

gth

depe

nds

on

si

ze o

f st

ones

and

con

stru

ctio

n

qu

ality

• Co

mm

only

use

d in

slo

pe s

tabi

lizat

ion

w

orks

• M

ade

with

larg

e re

ctan

gula

r ga

bion

bo

xes

fille

d w

ith s

tone

s. P

refe

rabl

e

w

here

flat

big

sto

ne a

re n

ot

av

aila

ble.

• Co

mm

only

use

d in

the

slo

pe

st

abili

zatio

n w

orks

• ad

e of

cem

ent

mor

tar

or c

oncr

ete

• Pe

rman

ent

stru

ctur

es

• U

sed

to p

rote

ct im

port

ant

in

fras

truc

ture

, suc

h as

roa

d, b

uild

ing.

Adv

anta

ges

• U

ses

loca

l mat

eria

ls, s

impl

e, a

nd

lo

w c

ost

• O

nce

root

s an

d sh

oots

are

put

out

,

fo

rms

a lo

ng-t

erm

bar

rier

• U

ses

loca

l mat

eria

ls, s

impl

e an

d

lo

w c

ost

• Pr

ovid

e go

od d

rain

age;

flex

ible

;

re

lativ

ely

low

cos

t

• Pr

ovid

e go

od d

rain

age;

flex

ible

and

re

lativ

ely

low

cos

t.

• Su

itabl

e, w

here

who

le la

nd m

ass

is

m

ovin

g.

• Pe

rman

ent

stru

ctur

e

• Lo

oks

good

Dis

adva

ntag

e/ L

imit

atio

n•

Take

s tim

e to

roo

t.

• Su

itabl

e fo

r ge

ntle

slo

pe a

nd s

hort

er

sl

ope

leng

th

• N

ot s

uita

ble

whe

re la

nd m

ass

is

m

ovin

g.

• Su

itabl

e

- w

here

goo

d qu

ality

(fla

t an

d bi

g)

s

tone

is a

vaila

ble

- f

or t

he s

hort

er s

lope

leng

th

- f

or s

mal

l mas

s m

ovem

ent

• Co

stly

• Co

st o

f th

e ga

bion

leav

es t

he

co

mm

unity

.

• N

eeds

ski

lled

labo

r fo

r co

nstr

uctio

n

• Co

stly

and

Cos

t of

mat

eria

ls (

cem

ent,

ro

ds)

leav

es t

he c

omm

unity

• N

eeds

com

plic

ated

eng

inee

ring

de

sign

and

ski

lled

labo

r.

• Po

or d

rain

age

• Ca

nnot

tol

erat

e se

ttle

men

t of

gro

und


Des

ign

/ C

onst

ruct

ion

spec

ifica

tion

Crib

wal

lLo

ose

ston

e re

tain

ing

wal

lG

abio

nM

ason

ry /

Con

cret

e

• Th

e cr

ib w

all s

houl

d no

t be

hig

her

than

4m

for

pol

e or

2m

for

ba

mbo

o

• Pl

ace

woo

den

pole

or

thre

e ba

mbo

os t

ied

toge

ther

in a

tria

ngul

ar

sh

ape

(A)

alon

g th

e fr

ont

side

of

the

crib

wal

l.

• Pl

ace

a po

le /

bam

boo

(B)

ever

y 1

to 2

m a

t a

dist

ance

apa

rt

pe

rpen

dicu

lar

to t

he h

oriz

onta

lly p

lace

d po

le /

bam

boos

in a

do

wn

slop

ing

angl

e of

15-

30 d

egre

e an

d tie

it t

oget

her

with

the

ho

rizon

tally

pla

ced

pole

/ b

ambo

os. F

or t

his

use

galv

aniz

ed w

ire.

• In

cas

e of

bam

boo

crib

wal

l, dr

ive

a liv

ing

/ ba

mbo

o po

le in

fro

nt

of

the

crib

wal

l to

prot

ect

the

horiz

onta

lly p

lace

d ba

mbo

os.

• In

cas

e of

woo

den

pole

crib

wal

l, th

e po

le p

lace

d pe

rpen

dicu

lar

to

the

hor

izon

tally

pla

ced

pole

s is

gro

oved

at

the

end,

so

that

th

e ho

rizon

tally

pla

ced

pole

can

res

t on

it. T

here

fore

, no

pegg

ing

in

fro

nt is

req

uire

d.

• Th

e to

p w

idth

of

the

reta

inin

g w

all

sh

ould

not

be

less

tha

n 60

cm

for

st

one

mas

onry

and

55

cm f

or b

rick

w

alls

.

• Th

e fo

unda

tion

shou

ld b

e de

ep

en

ough

to

safe

guar

d ag

ains

t

w

eath

er a

nd s

houl

d be

at

leas

t

h/

10+3

0 cm

bel

ow t

he g

roun

d

le

vel.

• Th

e fr

ont

face

sho

uld

have

a b

atte

r

of

at

leas

t 1h

:2v,

with

max

imum

of

1h

:6v.

• Th

e ba

ck s

houl

d be

left

rou

gh o

r

bu

ilt in

ste

ps t

o in

crea

se f

rict

ion

be

twee

n th

e w

all a

nd t

he b

ack

fill

• Pr

even

t w

ater

pre

ssur

e be

hind

the

w

all b

y ba

ckfil

ling

prop

erly

with

co

arse

mat

eria

l and

allo

win

g

dr

aina

ge w

ith w

eep

hole

s.

• Th

e ba

ckfil

l sho

uld

be c

ompa

cted

af

ter

ever

y fil

ling

of 1

0 cm

to

15 c

m

th

ick

laye

r.

• Th

e no

rmal

wid

th t

o he

ight

rat

io is

:

w

idth

= ½

hei

ght

+ 0.

5.

• En

sure

dra

inag

e is

pro

vide

d fr

om t

he

lo

wes

t po

int

of t

he f

ound

atio

n.

• Si

ze o

f th

e G

abio

n Bo

x: U

sual

ly

in

Nep

al g

abio

ns a

re 3

m x

1.5

m x

0.

75 m

mad

e of

8-g

auge

gal

vani

zed

w

ire

with

15

cm b

y 15

cm

mes

h.

Yo

u ca

n de

sign

the

gab

ion

boxe

s of

yo

ur o

wn

size

. For

pra

ctic

al p

urpo

ses

th

e di

men

sion

of

the

boxe

s m

ust

be

m

ultip

le o

f 15

cm

in c

ase

of 8

-gau

ge

ga

bion

box

es o

r 10

by

10 c

m in

cas

e

of

10-

gaug

e ga

bion

box

es.

• Sa

me

dim

ensi

ons

as lo

ose

ston

e

re

tain

ing

wal

l.

• Th

e w

eep

hole

s ar

e ev

en m

ore

ne

cess

ary

for

mas

onry

wal

ls t

han

fo

r dr

y ru

bble

ret

aini

ng w

alls

.

• Th

e w

eep

hole

s sh

ould

be

4 in

ch

sq

uare

, and

pla

ced

ever

y 3

feet

ap

art

hori

zont

ally

and

2 f

eet

apar

t

ve

rtic

ally

. The

y sh

ould

not

be

ve

rtic

ally

one

und

er t

he o

ther

.

• Fi

ll th

e so

il m

ater

ial i

n th

e op

enin

g be

twee

n th

e po

les

or

ba

mbo

os a

nd p

ress

with

out

leav

ing

any

void

s.

• Pu

t br

anch

es o

f sp

rout

ing

livin

g pl

ants

in t

he o

pen

spac

es

be

twee

n th

e po

les

or b

ambo

os in

suc

h a

way

tha

t no

t m

ore

than

¼

of

thei

r le

ngth

pro

trud

es.

• Re

peat

the

ste

ps u

ntil

the

desi

gned

hei

ght

is a

ttai

ned.

At

the

top,

pl

ace

the

horiz

onta

lly p

lace

d ba

mbo

o pl

oes

in s

uch

a w

ay t

hat

a

ba

mbo

o pe

g ca

n be

driv

en in

a s

pace

bet

wee

n ho

rizon

tally

pl

aced

bam

boo

one

belo

w a

nd a

bove

.

• Ti

ltin

g th

e w

all t

owar

ds t

he h

ill s

lope

incr

ease

s th

e st

abili

ty o

f th

e w

all a

nd it

s ef

fect

iven

ess.

Typ

ical

ly, w

alls

may

be

til

ted

by 6

to

10 d

egre

es.

• Fo

r gr

eate

r he

ight

ret

aini

ng w

alls

, ste

ppin

g is

rec

omm

ende

d to

incr

ease

the

ir s

tabi

lity.

• A

fter

the

con

stru

ctio

n, e

nsur

e th

at t

he s

lope

s ar

ound

the

str

uctu

re a

nd u

p-sl

ope

are

trea

ted

usin

g ap

prop

riat

e

bi

oeng

inee

ring

mea

sure

s. R

emov

e al

l sur

plus

deb

ris

to a

void

the

ero

sion

and

slu

mpi

ng.

• D

ry w

alls

co-

exis

t w

ith, a

nd a

re s

tren

gthe

ned

by p

lant

roo

ts. E

ncou

rage

or

plan

t ve

geta

tion.


Mat

eria

l

Crib

wal

lLo

ose

ston

e re

tain

ing

wal

lG

abio

nM

ason

ry /

Con

cret

e

• Ba

mbo

o or

rou

nd /

squ

are

timbe

r /

log

(1

0 –

15 c

m in

dia

met

er)

• Li

ve c

uttin

g th

at r

oots

eas

ily, a

t le

ast

1 m

le

ngth

with

a la

rge

num

ber

of s

ide

br

anch

es

• Sp

rout

ing

woo

den

pole

s of

8 t

o 12

cm

di

amet

er o

r ba

mbo

o po

le a

bout

1 m

long

.

• G

ood

qual

ity s

tone

(St

rong

, big

, and

flat

st

ones

are

pre

ferr

ed)

• G

abio

n bo

x

• G

ood

qual

ity s

tone

(St

rong

, big

, and

flat

st

ones

are

pre

ferr

ed)

• Sp

ecifi

catio

n of

gab

ion

box:

• Ce

men

t

• Sa

nd

• G

ood

qual

ity s

tone

(St

rong

, big

and

flat

st

ones

are

pre

ferr

ed)

Cons

truc

tion

per

iod

Crib

wal

lLo

ose

ston

e re

tain

ing

wal

lG

abio

nM

ason

ry /

Con

cret

e

• D

urin

g D

orm

ant

seas

on if

the

site

is m

oist

.

• Ju

st b

efor

e ra

iny

seas

on if

the

site

is d

ry

• A

ny t

ime

of t

he y

ear

whe

n it

is c

onve

nien

t,

ho

wev

er d

ry p

erio

d is

pre

fera

ble.

• Pl

ant

cutt

ings

just

bef

ore

rain

y se

ason

if t

he

si

te is

dry

. Pla

nt c

uttin

gs d

urin

g th

e

do

rman

t se

ason

if t

he s

ite is

moi

st.

• A

ny t

ime

of t

he y

ear

whe

n it

is c

onve

nien

t,

ho

wev

er d

ry p

erio

d is

pre

fera

ble.

• Pl

ant

cutt

ings

just

bef

ore

rain

y se

ason

if t

he

si

te is

dry

. Pla

nt c

uttin

gs d

urin

g th

e

do

rman

t se

ason

if t

he s

ite is

moi

st.

• A

ny t

ime

of t

he y

ear

whe

n it

is c

onve

nien

t,

ho

wev

er t

he d

ry p

erio

d is

pre

fera

ble.

• Pl

ant

cutt

ings

just

bef

ore

rain

y se

ason

if t

he

si

te is

dry

. Pla

nt c

uttin

gs d

urin

g th

e

do

rman

t se

ason

if t

he s

ite is

moi

st.

Mai

nten

ance

Crib

wal

lLo

ose

ston

e re

tain

ing

wal

lG

abio

nM

ason

ry /

Con

cret

e

• In

spec

t th

e cr

ib w

all r

egul

arly

dur

ing

the

ra

iny

seas

on. R

epai

r an

y op

enin

g be

fore

it

ge

ts w

orse

.

• Re

plac

e th

e de

ad c

uttin

gs.

• So

me

thin

ning

of

cutt

ing

may

be

requ

ired

af

ter

few

yea

rs.

• Re

pair

any

dam

age

imm

edia

tely

.

• Pr

ovid

e th

e ad

equa

te d

rain

age

syst

em in

th

e do

wnw

ard

side

.

• Ca

rry

out

plan

tatio

n of

app

ropr

iate

spe

cies

in

upw

ard

side

.

• Re

pair

any

ope

ning

of

the

gabi

on b

ox

im

med

iate

ly.

• Pr

ovid

e th

e ad

equa

te d

rain

age

syst

em in

th

e do

wnw

ard

side

.

• Ca

rry

out

plan

tatio

n of

app

ropr

iate

spe

cies

in

upw

ard

side

.

• Pr

ovid

e th

e ad

equa

te d

rain

age

syst

em in

th

e do

wnw

ard

side

.

• Ca

rry

out

the

imm

edia

te r

epai

r of

any

da

mag

e.

• Ca

rry

out

plan

tatio

n of

app

ropr

iate

spe

cies

in

upw

ard

side

.

• Cl

ean

the

clog

ging

of

the

wee

p-ho

le.

Prec

auti

ons

/ P

ract

ical

con

side

rati

ons

Crib

wal

lLo

ose

ston

e re

tain

ing

wal

lG

abio

nM

ason

ry /

Con

cret

e

• M

ake

sure

cut

tings

are

not

allo

wed

to

dry

in

th

e su

n.

• A

void

spl

ittin

g of

the

sta

kes

by p

laci

ng a

pi

ece

of s

tron

g w

ood

on t

he t

op o

f th

e

st

ake

whe

n it

is b

eing

driv

en in

.

• A

void

usi

ng t

hese

tec

hniq

ues

in a

poo

rly

dr

aine

d ar

ea s

ubje

ct t

o m

ediu

m t

o la

rge

sc

ale

slum

ping

.

• D

ress

all

ston

e (i

f it

is r

ound

ed)

into

re

ctan

gula

r bl

ocks

.

• O

verl

ap a

ll jo

ints

. Mai

ntai

n th

e jo

ints

in a

st

agge

red

fash

ion

as in

the

bri

ck m

ason

ry.

• U

se s

tone

s as

larg

e (b

igge

r th

an 1

5 cm

) as

po

ssib

le. I

f m

ainl

y sm

all s

tone

s ar

e

av

aila

ble,

use

larg

e on

es a

t le

ast

ever

y on

e

m

eter

to

impr

ove

the

tyin

g.

• St

ones

sho

uld

be t

abul

ar a

nd a

ngul

ar.

• Pa

ck a

ll st

ones

car

eful

ly a

nd d

ense

ly.

• En

sure

tha

t th

e m

inim

um d

imen

sion

of

all

st

ones

is la

rger

tha

n th

e w

ire

mes

h si

ze.

• En

sure

the

qua

lity

of t

he g

alva

nize

d w

ire.

• En

sure

pro

per

seal

ing

of t

he b

ox u

sing

12

SW

G w

ire.

• Sa

me

as lo

ose

ston

e re

tain

ing

wal

l.


• Th

e pr

ojec

tion

of a

ny f

ootin

g co

urse

sho

uld

no

t ex

ceed

hal

f th

e de

pth

of t

he c

ours

e.

• U

se fl

atte

r st

ones

for

the

top

laye

r. C

over

th

e to

p of

the

ret

aini

ng w

all w

ith s

oil o

r

bu

ild a

bou

nd m

ason

ry b

and

alon

g th

e to

p

to

sto

p it

unra

velin

g.

U

se t

hese

dim

ensi

ons

for

dry

ston

e

re

tain

ing

wal

ls, d

epen

ding

on

slop

e an

gle.

Th

is t

able

pro

vide

s a

guid

e to

the

di

men

sion

s of

wal

ls o

n di

ffer

ent

slop

es.

• W

ire

all g

abio

n bo

xes

toge

ther

usi

ng 1

2

SW

G w

ire,

allo

win

g an

add

ition

al 5

% o

f

w

ire

for

bind

ing

and

tyin

g.

Slop

eW

all H

eigh

tB

ase

heig

htTo

p w

idth

30 –

35°

1.5

– 2.

0m1.

25 –

1.5

m0.

75m

35 –

40°

2.0

– 2.

5m1.

5 –

2.0m

0.75

– 1

.0m

40 –

45°

2.5

– 3.

0m2.

0 –

2.3m

1.0m

• U

se o

f th

e ab

ove

men

tione

d di

men

sion

s do

es n

ot n

eed

the

stab

ility

tes

t ag

ains

t

ov

ertu

rnin

g, c

olla

psin

g, a

nd s

lidin

g.

• Fo

r a

com

plic

ated

des

ign,

con

sult

exp

erts

.

Refe

renc

es: F

AO

, 198

5., S

CWM

C, 2

001.

, Sth

apit,

K. M

., 19

98, D

SCW

M 2

004.


Titl

e: C

HEC

K D

AM

Wha

t is

it?

A s

mal

l, lo

w d

am c

onst

ruct

ed a

cros

s a

gully

or

any

othe

r w

ater

- co

urse

.

Func

tion

• M

inim

ize

the

chan

nel s

cour

ing

and

prev

ent

vert

ical

and

late

ral e

rosi

on b

y re

duci

ng t

he v

eloc

ity o

f w

ater

and

not

allo

win

g it

to r

un o

n

lo

ng s

lope

s.

• Co

nvey

the

run

off

safe

ly.

• Tr

ap t

he s

edim

ent

goin

g do

wns

trea

m.

• Ra

ises

the

bed

leve

l to

the

exte

nt t

hat

it ca

n su

ppor

t th

e un

stab

le s

ide

slop

es.

• St

ores

wat

er a

nd in

crea

ses

its in

filtr

atio

n /

perc

olat

ion

in t

he s

oil.

• Co

llect

s su

ffici

ent

soil

and

wat

er t

o pr

omot

e pl

ant

grow

th.

Type

Bru

shw

ood

Loos

e st

one

Bou

lder

Gab

ion

Mas

onry

/ C

oncr

ete

Gen

eral

char

acte

rist

ics

• M

ade

of w

oode

n po

les

an

d br

ush.

• Su

itabl

e fo

r sm

all

gu

llies

of

1 to

2 m

eter

s

in

wid

th a

nd d

epth

.

• Le

ast

perm

anen

t of

al

l typ

es, b

ut a

re

ch

eap

and

mad

e

w

ith lo

cally

ava

ilabl

e

m

ater

ials

.

• M

ade

of lo

ose

rock

s.

• St

abili

ty a

nd s

tren

gth

de

pend

s on

the

siz

e of

ro

cks

and

the

qual

ity o

f th

e

co

nstr

uctio

n.

• Co

mm

only

use

d in

the

gul

ly

co

ntro

l wor

ks in

sm

all t

o

m

ediu

m w

ater

cou

rse.

• Sa

me

as t

he lo

ose

ston

e

ch

eck

dam

s ex

cept

tha

t,

bi

g bo

ulde

rs a

re u

sed

in it

s’

co

nstr

uctio

n.

• M

ade

with

gab

ion

boxe

s

fil

led

with

sto

nes.

The

y ar

e

pr

efer

able

whe

re b

ig s

tone

s

ar

e no

t av

aila

ble.

• Co

mm

only

use

d in

the

gul

ly

co

ntro

l wor

ks in

med

ium

to

bi

g w

ater

cour

ses.

• M

ade

of c

emen

t m

orta

r

or

con

cret

e.

• Pe

rman

ent

stru

ctur

es.

• G

ener

ally

use

d to

pro

tect

im

port

ant

deve

lopm

ent

in

fras

truc

ture

, suc

h as

roa

ds,

bu

ildin

g.

Adv

anta

ges

• U

ses

loca

l mat

eria

ls, s

impl

e

an

d lo

w c

ost.

• O

nce

root

s an

d sh

oots

are

pu

t ou

t, it

for

ms

a lo

ng-t

erm

ba

rrie

r.

• U

ses

loca

l mat

eria

ls, s

impl

e

an

d lo

w c

ost

• U

ses

loca

l mat

eria

ls, s

impl

e

an

d lo

w c

ost.

• If

mad

e pr

oper

ly, a

lmos

t

a

perm

anen

t st

ruct

ure

lik

e ga

bion

s, m

ason

ry, a

nd

co

ncre

te s

truc

ture

s.

• Fl

exib

le, p

erm

eabl

e, a

nd

ec

onom

ical

com

pare

d to

ot

her

solid

str

uctu

res.

• Su

itabl

e, w

here

land

mas

s is

m

ovin

g.

• Pe

rman

ent

stru

ctur

e

• Lo

oks

good

Dis

adva

ntag

e•

Take

s tim

e to

est

ablis

h.•

Wea

k if

not

prop

erly

mad

e

an

d do

not

use

siz

eabl

e

st

ones

.

• Tr

ansp

ort

of t

he b

ig b

ould

ers

is

diffi

cult

if n

ot lo

cate

d

up

slop

e of

the

site

.

• La

rge

void

s in

the

dam

may

cr

eate

wat

er je

ts, w

hich

co

uld

be d

estr

uctiv

e if

di

rect

ed t

owar

ds b

anks

.

• Co

stly

• Co

st o

f th

e ga

bion

doe

s no

t

re

mai

n in

the

com

mun

ity.

• N

eeds

ski

lled

labo

r fo

r

co

nstr

uctio

n.

• Co

stly

• Co

st o

f th

e m

ater

ial

(c

emen

t, r

ods)

doe

s no

t

re

mai

n in

the

com

mun

ity.

• N

eeds

com

plic

ated

en

gine

erin

g de

sign

and

sk

illed

labo

r.


CHEC

K D

AM

Des

ign

spec

ifica

tion

Site

sel

ecti

onSe

lect

the

site

for

the

con

stru

ctio

n of

che

ck d

ams

taki

ng in

to a

ccou

nt t

he f

ollo

win

g co

nsid

erat

ions

:

• To

acc

omm

odat

e hi

gher

floo

d ru

n-of

f m

akes

it n

eces

sary

to

sele

ct a

pla

ce, w

hich

is w

ide

enou

gh t

o lim

it sp

ecifi

c ru

n-of

f (p

er m

eter

wid

th)

“q”

and

so t

he s

cour

de

pth.

The

spi

llway

has

to

be b

ig e

noug

h w

ith a

t le

ast

0.5m

fre

e bo

ard

to t

ake

flood

run

-off

, oth

erw

ise

the

side

fou

ndat

ion

of t

he c

heck

dam

s w

ill w

ash

out

and

th

e riv

er w

ill b

y-pa

ss t

he c

heck

dam

s an

d de

stro

y th

em.

• M

ake

chec

k da

ms

at a

str

aigh

t an

d fir

m s

trea

m b

ank.

Nev

er m

ake

chec

k da

ms

on t

he c

urve

, jun

ctio

n of

tw

o st

ream

s, o

r ju

st b

elow

it.

• Bu

ild t

he la

st c

heck

dam

on

good

fou

ndat

ion

of b

ase

rock

as

it af

fect

s th

e fo

unda

tion

of t

he r

est

of t

he c

heck

dam

s ab

ove.

• Th

e se

lect

ion

of t

he s

ite is

als

o re

stric

ted

by t

he h

eigh

t of

the

str

uctu

re. I

f th

e el

evat

ion

diff

eren

ce b

etw

een

two

succ

essi

ve s

ites

is t

oo h

igh,

one

or

mor

e si

tes

ha

ve t

o be

sel

ecte

d in

bet

wee

n so

tha

t th

e st

ruct

ure

heig

ht w

ill f

ulfil

l the

con

ditio

ns.

Spac

ing

Plac

e th

e ch

eck

dam

s so

tha

t th

e bo

ttom

of

the

uppe

r ch

eck

dam

and

the

top

of

the

low

er c

heck

dam

give

a g

radi

ent

that

for

the

kin

d of

soi

l in

the

stre

am g

ives

a n

on-e

rosi

ve v

eloc

ity o

f flo

w. T

his

is t

he

com

pens

atio

n gr

adie

nt.

For

the

gene

ral p

ract

ice,

the

com

pens

atio

n gr

adie

nt is

a 3

to

5% s

lope

. How

ever

, if

the

bed

mat

eria

ls

are

cour

se a

nd s

trea

m b

ed s

lope

is s

teep

, a s

teep

er c

ompe

nsat

ion

grad

ient

can

be

cons

ider

ed.

The

horiz

onta

l dis

tanc

e be

twee

n tw

o su

cces

sive

che

ck d

ams

is g

iven

by

the

rela

tion:

d

= h

* 10

0 /

(SÓ -

Se)

Whe

re,

d

= S

paci

ng b

etw

een

two

succ

essi

ve c

heck

dam

s (h

oriz

onta

l dis

tanc

e)

h

= H

eigh

t of

the

che

ck d

am (

up t

o no

tch)

S Ó

= E

xist

ing

slop

e of

bed

in %

S e

= St

abili

zing

slo

pe o

f be

d in

%. I

n ge

nera

l, it

is 3

- 5

%.

Exam

ple:

-

Giv

en:

h =

2m

S =

15%

Se =

5%

d =

h*10

0 /

(SÓ -

Se)

=2*

100/

(15-

5)=2

0m

Num

ber

of c

heck

dam

s is

cal

cula

ted

follo

win

g th

e fo

rmul

a: -

Num

ber

of C

heck

dam

s =

(a-b

)/ H

Whe

re,

a

= Th

e to

tal v

ertic

al d

ista

nce

betw

een

the

first

and

the

last

che

ck d

am in

tha

t po

rtio

n of

the

gu

lly o

r to

rren

t.

d=

The

hor

izon

tal d

ista

nce

betw

een

the

first

and

the

last

che

ck d

am in

tha

t po

rtio

n of

the

gully

or

torr

ent.

b

= Th

e to

tal v

ertic

al d

ista

nce

calc

ulat

ed a

ccor

ding

to

the

com

pens

atio

n gr

adie

nt f

or t

hat

port

ion

of t

he g

ully

.

H

= A

vera

ge h

eigh

t of

the

che

ck d

ams.

Giv

en:

a =

30m

Se =

5%

d =

200m

b =

Se*d

/10

0 =

10m

H =

2m

No

of C

heck

dam

=(a

-b)/

H =

(30-

10)/

2=10

Foun

dati

on•

The

dept

h of

fou

ndat

ion

mus

t be

bel

ow t

he s

cour

leve

l.

• In

ero

dibl

e st

rata

, if

D is

the

ant

icip

ated

max

imum

dep

th o

f sc

ouri

ng b

elow

the

des

igne

d hi

ghes

t flo

od le

vel,

incl

udin

g po

ssib

le c

once

ntra

tion

of fl

ow, t

he

m

inim

um d

epth

of

foun

datio

n be

low

the

hig

hest

floo

d le

vel s

houl

d be

tak

en a

s 1.

33 *

D.

• Th

e sc

our

dept

h is

not

tak

en f

rom

the

pre

sent

bed

leve

l but

fro

m o

ne t

o be

exp

ecte

d in

the

fut

ure

afte

r si

ltat

ion

of t

he lo

wer

che

ck d

am a

nd a

fter

the

es

tabl

ishm

ent

of n

ew b

ed g

radi

ent

due

to t

he r

educ

ed b

ed-l

oad

afte

r th

e er

osio

n co

ntro

l.

• Ta

ke a

min

imum

of

1.0

m f

ound

atio

n as

a r

ule

of t

hum

b.


Chec

k da

m

Des

ign

spec

ifica

tion

Scou

r de

pth

Scou

r oc

curs

whe

n th

e be

d ve

loci

ty o

f th

e st

ream

exc

eeds

the

vel

ocity

it t

akes

to

mov

e pa

rtic

les

of t

he

bed

mat

eria

l. Ve

loci

ty v

arie

s w

ith t

he g

radi

ent,

the

hyd

raul

ic d

epth

, and

the

cha

ract

eris

tics

of t

he b

ed

and

bank

s. W

hen

the

velo

city

of

the

wat

er s

low

s, s

ilt s

ettl

es; w

hen

the

velo

city

incr

ease

s, t

he w

ater

pick

s up

and

mov

es s

ilt. S

cour

is w

orst

whe

n th

e w

ater

in t

he r

iver

is f

allin

g so

it d

epen

ds m

ore

on

the

dept

h of

wat

er t

han

on t

he g

radi

ent.

A r

iver

has

to

adju

st it

s ve

loci

ty t

o th

e fo

rces

tha

t its

bed

and

bank

s ca

n st

and

by c

hang

ing

its s

ectio

n.

The

scou

ring

of t

he c

urre

nt is

not

uni

form

and

it is

all

alon

g th

e be

d w

idth

. Sco

urin

g is

dee

per

than

norm

al a

t ob

stru

ctio

ns a

nd a

t be

nds

in t

he r

iver

. The

refo

re, t

he m

axim

um d

epth

of

scou

ring

has

to

be

dete

rmin

ed.

Nor

mal

Sco

ur D

epth

:

i). S

choc

klit

ch’s

For

mul

a:

4.75

* h

0.2

* q0

.57

Scou

r D

epth

, Ds

= -

----

----

----

----

----

----

----

----

---

dm

0.35

Whe

re,

Ds =

Sco

ur d

epth

(in

met

er)

belo

w w

ater

leve

l

d m =

Gra

in d

iam

eter

(in

mm

) w

hich

div

ides

bed

mat

eria

l in

a w

ay t

hat

90 %

is s

mal

ler

than

dm

h =

Wat

er le

vel d

iffer

ence

(in

met

er)

abov

e an

d be

low

the

che

ck d

am

q =

Run-

off

(in

cubi

c m

eter

s /

met

er w

idth

) in

the

spi

llway

Exam

ple:

Giv

en: -

dm =

20cm

= 2

00m

m

h =

2m

q =

1.25

cum

ecs

/ m

eter

Ds

=(4

.75*

h 0.

2 *

q0.57

)/ d

m0.

35

=(4

.75*

2 0

.2 *

1.2

50.5

7)/

200

0.35

Ç7.

496/

6.39

Ç1.

17 m

Brea

dth

of S

cour

Hol

e =

Brea

dth

of S

cour

Hol

e=

1.5

* Le

ngth

of

the

Not

ch

Ç1.

5*4

= 6

met

ers

Leng

th o

f Sc

our

Hol

e =

Leng

th o

f Sc

our

Hol

e or

the

Apr

on

= 4*

(0.4

67 *

q 2/

3 )1.

5 *h0.

5

=4*

(0.4

67*1

.252/

3 )1.

5*20.

5

Ç4*

0.39

9*1.

42

Ç2.

26 m

.

Runo

ff e

stim

atio

nTh

e Ra

tion

al F

orm

ula

is:

Q

= C

* IT

c *

A /

360

Whe

re,

Q

= T

he r

ate

of r

un-o

ff in

cub

ic m

eter

per

sec

ond

i.e. c

umec

s =

IT

c =

The

inte

nsity

, tha

t is

the

rat

e of

rai

nfal

l in

mill

imet

ers

per

hour

for

des

igne

d fr

eque

ncy

f

or a

dur

atio

n eq

ual t

o th

e tim

e of

con

cent

ratio

n, T

c

A

= A

rea

of w

ater

shed

in h

ecta

res

C

= D

imen

sion

less

run

-off

coe

ffici

ent

Exam

ple:

Fact

orVa

lue

Rem

arks

I Tc =

240m

m/

hour

Valu

es a

re f

rom

cal

cula

tion

as c

arri

ed o

ut in

the

follo

win

g se

ctio

ns.

A

=22

.5 h

a

C =

0.33

5

Q =

(0.

335

* 24

0 *2

2.5)

/36

0 =

5 cu

mec

s

q =

1.25

cum

ecs/

met

er, i

f no

tch

leng

th =

4 m

eter

s

Proc

edur

e:

• M

easu

re t

he c

atch

men

t ar

ea “

A”

in h

ecta

res

by s

urve

ying

or

from

top

ogra

phic

al m

ap o

r ae

rial

ph

otog

raph

s.

Cult

ivat

ed la

nd A

1 =

10 h

a.

Past

ure

land

, A

2 =

7.5

ha

Fore

st la

nd,

A

3 =

5 h

a

Tota

l Are

a, A

= 2

2.5

ha.


• Ca

lcul

ate

the

Tim

e of

con

cent

ratio

n (i

.e. g

athe

ring

time)

by

usin

g th

e fo

rmul

a:

Tc

= L

1.15

/ 1

5 *

H 0.

38

Whe

re,

T c =

Tim

e of

con

cent

ratio

n (g

athe

ring

time)

in h

ours

L

= L

engt

h of

the

wat

ersh

ed a

long

the

mai

n st

ream

fro

m t

he o

utle

t to

the

mos

t di

stan

t ri

dge

in

kilo

met

ers,

and

H

= T

he d

iffer

ence

in e

leva

tion

betw

een

the

wat

ersh

ed o

utle

t an

d th

e m

ost

dist

ant

ridg

e in

kilo

met

ers

Exam

ple:

L =

700m

=

0.7

km

H =

50m

=

0.05

km

T c =

L 1.

15 /

15

* H

0.3

80.

7 1.

15 /

15

* 0.

05 0

.38

=0.

6635

/(1

5*0.

32)

0.13

8 ho

urs Ç

8m

inut

es

CHEC

K D

AM

Des

ign

spec

ifica

tion

Runo

ff e

stim

atio

n

cont

inue

d

Calc

ulat

e ra

infa

ll in

tens

ity f

or d

urat

ion

equa

l to

time

of c

once

ntra

tion.

Use

loca

l rai

nfal

l rec

ords

to

estim

ate

this

if p

ossi

ble.

Sin

ce, t

here

is n

o pu

blis

hed

reco

rds

of o

ne h

our

rain

fall

(mm

) fo

r N

epal

, for

thi

s pu

rpos

e, w

e ca

n dr

aw f

ollo

win

g in

form

atio

n fr

om t

he d

ata

prep

ared

for

Indi

a.

Freq

uenc

y an

d O

ne H

our

Rain

fall

in m

m.

Freq

uenc

y1

hour

rai

nfal

l (m

m)

10 Y

ears

fre

quen

cy

East

ern

and

Mid

dle

Zone

100

Wes

tern

and

Far

wes

tern

Zon

e80

25 Y

ears

fre

quen

cy

East

ern

and

Mid

dle

Zone

120

Wes

tern

and

Far

wes

tern

Zon

e10

0

50 Y

ears

fre

quen

cy

For

Who

le N

epal

120

Conv

ert

1- h

our

inte

nsity

to

inte

nsity

for

dur

atio

n eq

ual t

o ga

ther

ing

time

for

the

catc

hmen

t or

the

tim

e

of c

once

ntra

tion

i.e. I

Tc f

rom

the

figu

re t

o th

e le

ft.

Exam

ple:

Giv

en 2

5 ye

ars

freq

uenc

y, E

aste

rn Z

one:

-

I hr =

120

mm

T c =

8 m

inut

es

• M

ark

one-

hour

rai

nfal

l on

Y-ax

is.

• D

raw

a h

oriz

onta

l lin

e fr

om Y

-axi

s. W

e kn

ow t

hat

8 m

inut

es p

oint

lies

bet

wee

n 2

and

15

m

inut

es c

urve

. Mor

eove

r, 8

min

utes

poi

nt is

6 m

inut

es a

way

fro

m 2

min

utes

cur

ve t

owar

ds 1

5

m

inut

es c

urve

.

• Ex

trap

olat

e 8

min

utes

poi

nt o

n th

e ho

rizon

tal l

ine

draw

n fo

r 12

0 m

m/h

our

rain

fall

inte

nsity

.One hour rainfall intensity in mm / hour

Min

utes

96

0 48

0 24

0 12

0 60

30

15

2

180

160

140

120

100 80 60 40 20 10 0

0 40

80

12

0 16

0 20

0 24

0 28

0 32

0 36

0

Rain

fall

inte

nsity

for

dur

atio

n in

dica

ted

in m

m/

hour


• D

raw

a v

ertic

al li

ne f

rom

the

poi

nt e

xtra

pola

ted

for

8 m

inut

es t

ime

of c

once

ntra

tion

• Re

ad t

he v

alue

in t

he X

axi

s fo

r th

e Ra

infa

ll in

tens

ity f

or t

he t

ime

of c

once

ntra

tion

I Tc Ç

240

mm

Rela

tion

of O

ne H

our

Rain

fall

Inte

nsiti

es t

o In

tens

ities

at

othe

r

Dur

atio

n (c

onve

rted

and

red

raw

n fr

om G

. A. H

ataw

ay, M

ilita

ry

Air

Fie

ld -

Des

ign

of d

rain

age

faci

litie

s, T

rans

. Am

. Soc

. Civ

il

Engi

neer

s 11

0: 7

00. 1

945.

Cite

d by

Gup

ta, e

t. a

l. 19

73)

CHEC

K D

AM

Des

ign

spec

ifica

tion

Runo

ff e

stim

atio

nCa

lcul

ate

the

cons

tant

“C”

as

a m

easu

re o

f th

e pr

opor

tion

of t

he r

ain,

whi

ch b

ecom

es r

unof

f. Fo

llow

ing

Tabl

e be

low

giv

es s

ome

valu

e of

C.

Valu

e of

C f

or U

se in

Rat

iona

l For

mul

aLa

nd u

se t

ype

Soil

Type

Cult

ivat

edPa

stur

eFo

rest

With

abo

ve a

vera

ge in

filtr

atio

n ra

te, u

sual

ly s

andy

or

grav

ely

0.29

0.15

0.10

With

ave

rage

infil

trat

ion

rate

no

clay

pan

s, lo

ams

and

sim

ilar

soil

0.40

0.35

0.30

With

bel

ow a

vera

ge in

filtr

atio

n ra

te, h

eavy

cla

y so

ils, o

r

soils

with

a c

lay

pan

near

the

sur

face

, sha

llow

soi

ls a

bove

impe

rvio

us r

ock

0.50

0.45

0.40

Com

pute

d w

eigh

ted

“C”

for

the

wat

ersh

ed:

C

= (A

1* C

1 +

A2*

C2

+……

……

An*

Cn

)/ (

A1

+ A

2 +…

……

… A

n)

Whe

re,

A

1 , A

2 ,…

……

… A

n ar

e ar

eas

in h

ecta

res

unde

r va

riou

s la

nd u

se a

nd s

oil t

ypes

hav

ing

co

rres

pond

ing

valu

es o

f

C 1,

C2

,……

……

Cn

resp

ectiv

ely;

and

A =

A1

+ A

2 +…

……

… A

n =

Tota

l are

a of

the

wat

ersh

ed.

Lim

itat

ion:

Thi

s m

etho

d is

usu

ally

sug

gest

ed f

or u

se f

or a

wat

ersh

ed o

f le

ss t

han

50 h

ecta

res.

Exam

ple:

Land

use

cat

egor

yA

rea

Run-

off

coef

fici

ent

Cult

ivat

edA

1 =

10ha

C1=

0.29

Past

ure

A2

=7.

5ha

C2=

0.35

Fore

stA

3 =

5ha

C3=

0.40

C =

(A1*

C1

+ A

2* C

2 +

A2*

C2)

/ (

A1

+ A

2+ A

3)

=

(10*

0.29

+ 7

.5*0

.35+

5*0.

40)/

(10+

7.5+

5)

=

7.52

5/22

.5Ç

0.33

5

Not

ch d

esig

nO

nce

runo

ff is

cal

cula

ted,

des

ign

the

notc

h si

ze.

The

spill

way

has

to

acco

mm

odat

e pe

ak r

unof

f, w

hich

oth

erw

ise

will

was

h ou

t th

e si

de f

ound

atio

n of

the

chec

k da

m, a

nd d

estr

oy t

he c

heck

dam

. Des

ign

the

notc

h/w

eir

or s

pillw

ay u

sing

the

fol

low

ing

form

ula.

A. R

ecta

ngul

ar N

otch

:

Fran

cis’

s Fo

rmul

a:

Q =

1.8

4 *

Bsp

* H

sp 1.

5

Whe

re,

Q =

Pea

k ru

n-of

f, c

umec

s

B sp =

Len

gth

of N

otch

, in

met

ers

Hsp =

Hei

ght

of N

otch

, in

met

ers

For

trap

ezoi

dal n

otch

, cal

cula

te t

he le

ngth

of

the

notc

h as

the

ave

rage

of

top

and

bott

om w

idth

of

the

spill

way

/not

ch.

Exam

ple:

Calc

ulat

ed Q

= 5

cum

ecs

Case

1.

Case

2.

Fact

orVa

lue

Fact

orVa

lue

Hsp

=0.

75m

Hsp

=1m

Bsp

=3m

Bsp

=4m

Case

1.

Q =

1.8

4 *

Bsp

* H

sp 1.

5 =

1.84

* 3

*0.7

51.5

Ç1.

84 *

3*0

.65 Ç

3.5

cum

ecs

Sinc

e ca

lcul

ated

Q is

5 c

umec

s, t

he d

esig

n no

tch

cann

ot

acco

mm

odat

e th

e ru

noff

. The

refo

re, n

otch

siz

e ne

ed t

o be

incr

ease

d.

Case

2.

Q =

1.8

4 *

4*11.

5 Ç7.

36 c

umec

s >5

cum

ecs,

OK

q =

Q/

Bsp =

5/

4 =

1.25

cum

ecs

/ m

eter


Stru

ctur

al•

Stru

ctur

al d

esig

n in

volv

es t

he d

eter

min

atio

n of

the

dim

ensi

ons

of t

he v

ario

us c

ompo

nent

s of

the

che

ck d

am a

nd it

s st

reng

th a

nd s

tabi

lity.

• Sc

ourin

g en

dang

ers

the

safe

ty o

f th

e ch

eck

dam

s m

ost.

The

refo

re, t

he f

ound

atio

n de

pth

and

spill

way

siz

e an

d sh

ape

have

, the

refo

re, t

o be

sel

ecte

d ta

king

sc

ourin

g de

pth

into

con

side

ratio

n.

• Fo

r co

mpl

icat

ed d

esig

n, c

onsu

lt e

xper

ts.

CHEC

K D

AM

Gen

eral

spe

cific

atio

n (A

fter

Gey

ik, 1

986)

Type

of

chec

k da

mM

axim

um e

ffec

tive

Hei

ght

Min

imum

fou

ndat

ion

dept

h

Thic

knes

s of

dam

at

spill

way

leve

l

Slop

e of

dow

nstr

eam

face

of

the

dam

Slop

e of

ups

trea

m f

ace

of

the

dam

Thic

knes

s of

the

bas

e of

the

dam

Bru

shw

ood

Max

imum

hei

ght

is 1

m

from

gro

und

leve

l.

Woo

den

pole

s ar

e dr

iven

to

a de

pth

of a

bout

0.7

5-1

m.

Loos

e st

one

1.0

m0.

5 m

0.5

– 0.

7 m

20%

(1:

1/5

Ratio

)Ve

rtic

alCa

lcul

ated

acc

ordi

ngly

Bou

lder

2.0

mH

alf

of E

ffec

tive

Hei

ght

Pref

erab

ly 1

.0 m

30 %

(1

: 0.3

Rat

io)

Vert

ical

Calc

ulat

ed a

ccor

ding

ly

Gab

ion

May

var

y (R

ecom

men

ded

not

mor

e th

an 5

.0 m

)

Hal

f of

Eff

ectiv

e H

eigh

t>

1.0

m20

% S

lopp

ed, S

tepp

ed o

r

vert

ical

Step

ped

or v

ertic

alCa

lcul

ated

acc

ordi

ngly

Rem

arks

Use

of

the

dim

ensi

ons

abov

e do

es n

ot r

equi

re t

he s

tabi

lity

test

aga

inst

ove

rtur

ning

, col

laps

ing,

and

slid

ing.

How

ever

, the

siz

e of

the

spi

llway

nee

ds t

o be

com

pute

d

acco

rdin

g to

the

max

imum

dis

char

ge o

f th

e gu

lly c

atch

men

t ar

ea.

Cons

truc

tion

spe

cific

atio

n

Bru

shw

ood

Loos

e st

one

/ B

ould

erG

abio

n

• Cl

ear

the

site

and

mar

k th

e lin

e of

co

nstr

uctio

n us

ing

strin

g.

• D

ig a

tre

nch

of a

bout

15

cm d

eep

acro

ss t

he

gu

lly, d

rive

the

woo

den

pole

s in

to

a de

pth

of

ab

out

1/3

to ½

of

the

pole

leng

th, s

paci

ng

th

e po

les

30-5

0 cm

apa

rt.

• M

ake

the

tops

of

the

pole

s in

the

mid

dle

lo

wer

tha

n th

e si

des

to f

orm

a n

otch

of

the

re

quire

d si

ze t

o ac

com

mod

ate

the

max

imum

ru

noff

.

• W

eave

the

flex

ible

bra

nche

s of

tre

e (s

alix

,

po

plar

, vite

x, e

tc.)

and

shr

ub b

etw

een

w

oode

n po

les

driv

en in

to t

he g

roun

d un

til

th

e da

m is

the

req

uire

d he

ight

.

• Th

e en

ds o

f in

ter-

linke

d m

ater

ials

sho

uld

en

ter

at le

ast

30 c

m in

to t

he s

ides

of

the

gu

lly.

• Fi

ll th

e ba

ck o

f th

e br

ushw

ood

chec

k da

m

w

ith s

oil.

• Cl

ear

the

site

and

mar

k th

e lin

e of

con

stru

ctio

n us

ing

st

ring.

• Cu

t th

e si

des

of t

he g

ully

to

a sl

ope

of 1

:1. T

he

fo

unda

tion

of t

he w

ings

sho

uld

be m

ore

than

0.5

m

eter

s. E

nsur

e th

at t

he h

eigh

t of

the

win

g w

all i

s

le

vel w

ith t

he t

op o

f th

e ch

eck

dam

.

• Th

e fo

unda

tion

wid

th o

f th

e da

m h

as t

o be

mor

e

th

an t

he le

ngth

of

the

spill

way

.

• Fo

r la

rge

dam

s, c

onst

ruct

tw

o w

ing

wal

ls w

ith

ap

prop

riate

fou

ndat

ions

at

the

uppe

r si

de t

o di

rect

th

e flo

w in

to t

he s

pillw

ay o

r no

tch

and

prev

ent

it

fr

om d

amag

ing

the

bank

s.

• U

se la

rge

flat

ston

es o

n th

e no

tch

and

dow

nstr

eam

si

de o

f th

e sp

illw

ay. K

eep

the

cent

ral p

ortio

n lo

w f

or

th

e sp

illw

ay.

• W

hen

larg

e qu

antit

ies

of r

un-o

ff a

re e

xpec

ted,

it is

ad

visa

ble

to u

se s

ome

conc

rete

in t

he n

otch

and

the

cr

own

of t

he d

am, o

r to

cov

er e

very

thin

g w

ith a

w

ire n

ettin

g.

• Th

e st

ruct

ure

shou

ld e

nter

at

leas

t 0.

5 m

into

the

sid

e of

the

gul

ly a

nd b

e

pr

otec

ted

agai

nst

flash

wat

er b

y w

ing

wal

ls.

• Co

nstr

uct

the

win

g w

alls

with

app

ropr

iate

fou

ndat

ions

at

the

uppe

r si

de t

o gu

ide

th

e flo

w in

to t

he s

pillw

ay o

r no

tch

and

prev

ent

it fr

om d

amag

ing

the

bank

s. F

ill

th

e sp

ace

betw

een

the

dam

and

win

g th

e w

alls

with

soi

l.

• Th

e w

ing

wal

ls s

houl

d en

ter

at le

ast

0.5

m in

to t

he s

ide

of t

he g

ully

. The

hei

ght

of

th

e w

ing

wal

ls m

ust

leve

l with

the

top

of

the

chec

k da

m.

• Th

e fo

unda

tion

wid

th o

f th

e ch

eck

dam

has

to

be m

ore

than

the

leng

th o

f th

e

sp

illw

ay.

• Pu

t la

rge

flat

ston

es a

long

the

sid

es o

f th

e ga

bion

box

es, fi

ll sm

alle

r on

es in

the

m

iddl

e. T

he s

ize

of s

tone

s us

ed f

or t

he c

onst

ruct

ion

shou

ld b

e la

rger

tha

n th

e si

ze

of

the

wir

e m

esh.

• W

hen

debr

is is

exp

ecte

d, it

is a

dvis

able

to

prot

ect

the

spill

way

and

ste

ps in

the

fr

ont

part

of

the

dam

s by

a la

yer

of c

oncr

ete

to p

rote

ct t

he g

abio

n w

ire

from

cu

ttin

g by

the

fal

ling

debr

is.

• Co

mpu

te t

he s

pillw

ay d

imen

sion

s ac

cord

ing

to t

he m

axim

um d

isch

arge

est

imat

ed

fr

om t

he g

ully

cat

chm

ent.

• Be

low

the

dam

, an

apro

n ha

s to

be

cons

truc

ted.

• Fi

ll th

e ba

ck o

f th

e ch

eck

dam

s w

ith s

oil f

or g

reat

er s

tren

gth.


• M

ake

a br

ushw

ood

apro

n of

abo

ut 1

.5 -

2

tim

es t

he h

eigh

t of

che

ck d

am t

o pr

otec

t th

e

ch

anne

l fro

m s

cour

ing.

It n

eeds

to

be

an

chor

ed w

ith g

alva

nize

d w

ire.

• Pr

ovid

e si

dew

alls

to

dire

ct t

he fl

ow t

o th

e

w

eir

(cen

ter)

.

• Co

rrec

t th

e sl

ope

of a

ste

ep g

ully

hea

d.

• Be

low

the

dam

an

apro

n ha

s to

be

cons

truc

ted

with

st

ones

.

• Pl

ace

the

larg

e st

ones

in t

he b

otto

m o

f th

e da

m a

nd

us

e st

ones

of

abou

t 50

cm

x 3

0 cm

thr

ough

out

the

bo

dy o

f th

e ch

eck

dam

.

• O

n th

e up

-str

eam

sid

e, t

he d

am h

as t

o ge

t an

ear

th

fil

l for

gre

ater

str

engt

h.

• Fi

nally

, sup

plem

ent

the

stru

ctur

e by

pla

ntin

g

se

edlin

gs a

nd c

uttin

gs o

f su

itabl

e sp

ecie

s w

ith a

de

nse

and

wid

e sp

read

roo

t sy

stem

.

• Fi

nally

, sup

plem

ent

the

stru

ctur

e by

pla

ntin

g se

edlin

gs a

nd c

uttin

gs o

f su

itabl

e

sp

ecie

s w

ith a

den

se a

nd w

ide

spre

ad r

oot

syst

em o

n th

e gu

lly s

ides

.

• Th

e ga

bion

box

es n

eed

to b

e la

ced

toge

ther

ver

y st

rong

ly w

ith t

he 8

gau

ge w

ires

.

Mai

nten

ance

Bru

shw

ood

Loos

e st

one

/ B

ould

erG

abio

n

• In

spec

t th

e gu

lly a

fter

eac

h st

orm

. Rep

air

any

sc

ourin

g of

pol

es b

efor

e it

gets

wor

se.

• Cl

ose

the

open

ing

in t

he ja

fri (

brus

h).

Chec

k da

m c

an c

olla

pse

if:

a) E

ven

one

ston

e of

the

spi

llway

sec

tion

is w

ashe

d ou

t.

b) T

he f

ound

atio

n of

the

che

ck d

am is

sco

ured

.

c) T

he w

ater

flow

s fr

om t

he s

ide

foun

datio

n of

the

ch

eck

dam

.

Ther

efor

e, c

ontin

uous

mon

itori

ng o

f th

ese

inci

denc

es

is e

ssen

tial a

nd if

any

dam

age

is s

een,

car

ry

out

mai

nten

ance

and

fur

ther

con

trol

mea

sure

s

imm

edia

tely

. Als

o, t

o re

duce

the

dam

age

to t

he c

heck

dam

s, r

emov

e bo

ulde

rs, t

rees

, bus

hes,

and

oth

er fl

ow

rest

rictio

ns t

hat

wou

ld r

esul

t in

the

ban

k cu

ttin

g or

over

topp

ing

of t

he c

hann

el.

Sam

e as

loos

e st

one

/ b

ould

er c

heck

dam

. Als

o ch

eck

the

gabi

on w

ires

are

inta

ct.

Repa

ir a

ny lo

ose

or b

roke

n w

ire

in t

ime.

Prec

auti

ons

• A

void

spl

ittin

g of

the

sta

kes

by p

laci

ng a

pie

ce

of

str

ong

woo

d on

the

top

of

the

stak

e w

hen

it

is b

eing

driv

en in

.

• A

fter

the

str

uctu

re is

bui

lt, t

ram

p ea

rth

solid

ly

be

hind

and

aro

und

it to

pre

vent

cra

ckin

g.

• Th

e w

ater

mus

t go

ove

r th

e st

ruct

ures

and

no

t go

aro

und

them

.

• Th

e w

ater

way

s sh

ould

not

be

used

as

path

s.

• St

reng

th o

f th

e ch

eck

dam

dep

ends

on

the

qual

ity

of

the

con

stru

ctio

n i.e

. lay

ing

of t

he s

tone

in t

he

st

ruct

ure.

Ens

ure

bond

ing

betw

een

the

ston

es w

ithin

th

e st

ruct

ure.

• Bi

g st

one

need

s to

be

plac

ed a

t th

e sp

ill w

ay a

nd a

t

th

e fo

unda

tion.

• A

ny f

all o

f th

e st

one

from

the

spi

llway

to

the

stru

ctur

e ea

sily

cut

the

gab

ion

wir

e.

Th

eref

ore,

pro

tect

the

gab

ion

wir

e of

the

fou

ndat

ion

from

the

fal

ling

debr

is b

y

co

veri

ng it

with

sto

ne.

• Se

al t

he g

abio

n bo

x pr

oper

ly. A

ny o

peni

ng in

the

gab

ion

box

easi

ly w

ashe

s ou

t

th

e st

ones

.


Cons

truc

tion

per

iod

Bru

shw

ood

Loos

e st

one

/ B

ould

erG

abio

n

• D

urin

g D

orm

ant

seas

on if

the

site

is m

oist

.

• Ju

st b

efor

e ra

iny

seas

on if

the

site

is d

ry

• A

ny t

ime

if no

n-sp

rout

ing

spec

ies

are

used

.

• A

ny t

ime

of t

he y

ear

whe

n it

is c

onve

nien

t, h

owev

er

dr

y pe

riod

is p

refe

rabl

e.

• A

ny t

ime

of t

he y

ear

whe

n it

is c

onve

nien

t, h

owev

er t

he d

ry p

erio

d is

pre

fera

ble.

Refe

renc

es: G

eyik

, M. P

., 19

86.,

Hill

er, B

. 197

9, G

upta

et.

al.,

197

3.. 1

979.

Sth

apit,

K. M

. and

L. C

. Ten

nyso

n, 1

991.

, Tau

tsch

er, O

tto.

, 197

8/79

, DSC

WM

200

4.


Titl

e: W

ATE

R H

ARV

ESTI

NG

PON

D

Pond

(ne

w o

r ol

d) u

sed

for

stor

age

of r

un-o

ff w

ater

dur

ing

exce

ss r

ain

to r

educ

e er

osio

n an

d fo

r la

ter

use.

Func

tion:

Lim

itatio

n

• St

ore

surf

ace

runo

ff /

was

tew

ater

to

redu

ce s

oil e

rosi

on a

nd t

orre

nt•

If th

e so

urce

is n

ot p

eren

nial

suc

h as

rai

n, t

he p

ond

may

not

ha

ve w

ater

thr

ough

out

the

year

.•

Gra

dual

ly s

oaks

wat

er in

to g

roun

d im

prov

ing

soil

moi

stur

e.

• U

se o

f st

ored

wat

er f

or e

cono

mic

pro

duct

ion

(aah

ale,

irr

igat

ion,

fish

erie

s, e

nter

tain

men

t).

Type

by

linin

g

Eart

h lin

ing

Ston

e lin

ing

Cem

ent

linin

gPl

asti

c lin

ing

Rem

arks

Clay

lini

ng is

che

ap, m

aint

enan

ce is

easy

and

in lo

ng r

un m

ore

dura

ble.

Ston

e lin

ing

is c

ostl

y an

d du

rabl

e an

d

has

aest

hetic

val

ue.

Cem

ent

linin

g is

cos

tly

and

if cr

ack

deve

lops

, it

is d

ifficu

lt t

o m

aint

ain.

Plas

tic li

ning

look

s ex

otic

but

req

uire

s

regu

lar

repl

acem

ent.

Type

by

cons

truc

tion

Dug

out

pon

dRa

ised

pon

dCo

mbi

ned

pond

Rem

arks

This

is h

ow t

he p

onds

wer

e m

ade

in p

ast.

Alt

houg

h in

the

beg

inni

ng s

eepa

ge lo

ss

is m

ore,

with

tim

e se

epag

e lo

ss is

gre

atly

redu

ced.

With

ext

erna

l sup

port

man

y pr

ojec

ts m

ade

mas

onry

rai

sed

pond

s. H

owev

er, a

fter

cra

cks

deve

lope

d m

any

pond

s re

mai

n un

used

.

In h

ill t

opog

raph

y, d

ue t

o lo

w s

oil d

epth

mos

t

site

s ar

e su

itabl

e fo

r m

akin

g pa

rtly

dug

out

and

part

ly r

aise

d po

nd.

Adv

anta

geD

isad

vant

age

• Pr

ovid

es m

ultip

le b

enefi

ts if

des

igne

d m

ulti-

purp

ose.

• Ev

apor

atio

n lo

ss is

sig

nific

ant

in p

ond

with

big

sur

face

are

a.


Cons

truc

tion

ste

ps

Surv

ey s

teps

Map

ping

Mea

sure

men

tA

sses

smen

tEs

tim

atio

n

• Co

nstr

uctio

n si

te f

or p

ond

• Ca

tchm

ent

boun

dary

• D

iffer

ent

land

use

typ

es a

nd

dr

aina

ge li

nes

and

eros

ion

fe

atur

es (

mic

ro-g

ully

, rill

s, s

lope

fa

ilure

) re

quiri

ng d

iffer

ent

m

easu

res

in t

he c

atch

men

t

• A

lignm

ent

for

Inle

t an

d O

utle

t

• M

easu

re t

he c

ross

-sec

tions

at

X a

nd Y

dir

ectio

ns a

t ev

ery

3

m

eter

s in

terv

al c

over

ing

at le

ast

10

met

ers

mor

e on

eith

er s

ide

of

th

e co

nstr

uctio

n si

tes.

• Le

ngth

of

conv

eyan

ce s

yste

m

• A

vera

ge a

nd m

inim

um s

oil d

epth

at

the

con

stru

ctio

n si

te f

or

de

sign

ing

the

pond

and

es

timat

ing

quan

tity

of w

orks

• A

sses

s th

e so

il ty

pe o

f th

e

co

nstr

uctio

n si

te

• A

sses

s av

aila

bilit

y of

cla

y so

il an

d

co

nstr

uctio

n m

ater

ials

.

• D

iffer

ent

land

use

typ

es a

nd c

onse

rvat

ion

m

easu

res.

• Co

nser

vatio

n m

easu

res

requ

ired

on

eith

er s

ide

of

the

inle

t an

d ou

tlet

cha

nnel

s.

• Co

mm

and

area

if t

he p

ond

is f

or ir

riga

tion.

• Se

dim

ent

deliv

ery

from

the

cat

chm

ent:

-

o

5 -

10 c

u.m

./ha

./ye

ar f

rom

goo

d ca

tchm

ent,

o

10 -

15

cu.m

./ha

./ye

ar f

rom

mod

erat

e

catc

hmen

t

o

40 c

u.m

./ha

./ye

ar f

rom

poo

r ca

tchm

ent

Site

sel

ecti

on

For

harv

estin

g su

rfac

e ru

noff

,

loca

te a

t lo

wes

t la

nd a

rea,

so t

hat

the

larg

est

volu

me

of

wat

er c

an b

e st

ored

.

For

harv

estin

g st

ream

runo

ff, l

ocat

e th

e si

te s

o th

at

runo

ff f

rom

the

sou

rce

can

conv

enie

ntly

fed

to

the

pond

.

For

emba

nkm

ent

dam

, loc

ate

whe

re m

axim

um s

tora

ge

volu

me

is o

btai

ned

from

min

imum

siz

e of

dam

.

For

tapp

ing

wat

er f

rom

spri

ng a

nd w

ater

tap

, loc

ate

imm

edia

tely

bel

ow a

nd c

lose

to s

uch

sour

ce.

For

easy

wat

er u

se f

or

lives

tock

, loc

ate

clos

e to

the

trai

l and

abo

ve c

omm

and

area

for

irri

gatio

n.

For

dug

out

pond

, a s

ite

havi

ng fl

at t

erra

in w

ith h

eavy

soil

is s

uita

ble.

Des

ign

cons

ider

atio

n: W

ater

har

vest

ing

pond

has

thr

ee c

ompo

nent

s na

mel

y: S

ourc

e, S

tora

ge a

nd s

ervi

ce a

rea

Sour

ce: i

t m

ay b

e a

catc

hmen

t ar

ea g

ener

atin

g ru

noff

or

sprin

g, s

trea

m, o

r pi

pe w

ater

Stor

age

area

: mai

nly

depr

essi

on a

rea

eith

er n

atur

al o

r

man

mad

e to

hol

d th

e w

ater

i.e.

pon

d,

Serv

ice

area

: whe

re h

arve

sted

wat

er is

use

d

Month

Average No of rainy days

Remarks 1 rainy day in days

Monthly Rainfall

Rainfall per Event Period in mm

Runoff coefficient

Runoff in cu. m per hectare per event period

Pond size cu.m. (H)

Catch area in ha to harvest runoff to fill given conservation pond size in

cu. m.

AB

C =

30/

BD

E=D

/BF

G=

E*F*

10H

I=H

/G

May

113

339

310.

1855

.530

05.

4

Month

Rainfall per Event Period in mm

Runoff coefficient

Runoff in cu. m per hectare per event period

Catch Area in ha (J)

Pond size in cu. m. required for given catch area in

hectare

AE

FG

= E*

F*10

JK

= J *

G

May

310.

1855

.52

111.

1

Month

Appropriate cumulative days for water harvest

Crop water requirement l/sec/ha

Crop water requirement in cu. m. / ha / day

Given Pond Size in cu. m.

Command area in ha (Q)

AL

= C

MK

Q=

May

32

172.

811

1.1

0.24


Inle

t st

ruct

ure

for

wat

er c

olle

ctio

n

Cons

truc

t w

ater

way

s to

lead

wat

er f

rom

the

sou

rce

into

the

pon

d. F

or s

afe

wat

er r

egul

atio

n, a

flow

con

trol

mec

hani

sm m

ust

be s

et a

t

the

inle

t an

d ou

tlet

of

the

pond

.

Gra

ss w

ater

way

s ar

e re

com

men

ded

for

chan

nel s

lope

s up

to

8%. C

hann

el s

lope

s of

mor

e th

an 8

% s

houl

d be

sto

ne p

aved

or

lined

. The

shap

e of

the

gra

ss w

ater

way

s sh

ould

be

para

bolic

whe

re a

s a

trap

ezoi

dal s

hape

is p

refe

rabl

e fo

r st

one

pave

d w

ater

way

s.

Ove

rflow

spi

llway

/ C

hann

el

Prov

ide

an o

verfl

ow s

pillw

ay a

nd c

hann

el t

o di

spos

e sa

fely

of

exce

ss w

ater

. Ove

rflow

cha

nnel

hav

ing

the

sam

e w

idth

as

inflo

w c

hann

el

mus

t be

10

% h

ighe

r th

an in

flow

cha

nnel

.

In t

he p

onds

con

stru

cted

for

irri

gatio

n, p

rovi

de a

con

trol

labl

e ou

tlet

(m

ainl

y pi

ped

with

gat

e va

lve)

at

the

bott

om o

f th

e po

nd. T

here

shou

ld n

ot b

e an

y le

akag

e. T

here

fore

, ass

ure

a go

od c

onta

ct b

etw

een

such

a m

echa

nism

and

the

wal

l of

the

pond

, mos

t pr

efer

ably

by

cem

ent-

conc

rete

.

Maj

or p

robl

ems

Seep

age

loss

esEv

apor

atio

n lo

sses

Sedi

men

tati

on

• H

igh

seep

age

loss

–

Mor

e po

rous

the

soi

l

–

Mor

e cr

acks

in t

he r

ock

–

Fres

hly

cons

truc

ted

pond

s

•

Up

to 1

0 cm

/day

•

See

page

loss

var

ies

(0.2

6-16

cm/d

ay)

with

wat

er d

epth

• 5

cm /

day

are

cons

ider

ed t

o be

per

mis

sibl

e fo

r

th

e du

gout

pon

ds

• D

epen

ds o

n cl

imat

ic c

ondi

tions

– T

empe

ratu

re, h

umid

ity, w

ind

spee

d an

d ra

diat

ion

•

Lar

ger

the

surf

ace

area

hig

her

the

evap

orat

ion

•

Evap

orat

ion

loss

es m

ay b

e

– U

p to

50

% o

f to

tal s

tora

ge lo

sses

in o

pen

s

hallo

w r

eser

voir

and

Up

to 2

0 %

in d

eep

rese

rvoi

r

– 0

.4 –

0.6

cm

/ d

ay is

con

side

red

to b

e pe

rmis

sibl

e

• Re

duce

s ca

paci

ty

• M

ajor

pro

blem

in r

unof

f ha

rves

ting

pond

Reco

mm

ende

d m

easu

res

Seep

age

loss

esEv

apor

atio

n lo

sses

Sedi

men

tati

on

• Im

prov

e po

nd li

ning

-

Use

of

Clay

: Ste

p fo

r Cl

ay li

ning

-

Vert

ical

see

page

loss

m

Add

a f

oot

thic

k he

avy

clay

. Add

ition

of

cow

-dun

g an

d pu

ddlin

g by

the

live

stoc

k w

ill h

elp

the

seal

ing

of fl

oor.

Hig

her

the

dept

h of

pud

dlin

g le

ss t

he s

eepa

ge lo

ss

-

Hor

izon

tal s

eepa

ge lo

ss

m

30

cm w

ide

heav

y cl

ay c

ompa

cted

bet

wee

n th

e po

nd w

all a

nd t

he g

roun

d

m

If

ther

e is

hea

vy c

lay

arou

nd t

he c

onst

ruct

ion

site

, bef

ore

digg

ing,

suc

h cl

ay s

houl

d be

put

asi

de

-

Use

of

Low

Den

sity

Pol

ythe

ne: S

tep

for

plas

tic li

ning

m

Sha

pe t

he s

ide

slop

e of

the

pon

d to

less

tha

n 1:

1 (V

:H)

m

Rem

ove

all p

rotr

udin

g st

ones

, roo

ts e

tc. a

nd r

amm

ed t

o sm

ooth

en t

he s

urfa

ce.

m

Pla

ster

the

sid

es a

nd b

otto

m o

f th

e po

nd w

ith s

ieve

d cl

ay (

6) :

cow

-dun

g (1

)

m

Nea

tly

line

the

LDPE

with

out

any

fold

s ov

er t

he p

ond.

Kee

p ov

erla

p of

abo

ut 5

0 cm

at

the

join

t.

• N

o ef

fect

ive

solu

tion

to r

educ

e

ev

apor

atio

n lo

sses

, exc

ept

to

re

duce

the

exp

osed

are

a an

d

in

crea

se h

eigh

t to

ac

com

mod

ate

the

volu

me.

H

owev

er, t

here

is a

lim

it to

th

e he

ight

incr

ease

.

• U

nles

s it

is e

mba

nkm

ent

dam

,

pr

efer

able

hei

ght

is u

p to

2

m

eter

s.

• La

nd u

se t

reat

men

t in

the

ca

tchm

ent

• Pr

ovid

e a

sedi

men

t tr

ap b

efor

e

th

e po

nd.

• Pr

ovid

e a

sedi

men

t flu

shin

g

m

echa

nism

and

use

it

re

gula

rly


m F

old

the

over

lapp

ed s

ectio

n to

red

uce

the

leak

age.

m

To

prov

ide

good

anc

hora

ge, t

he s

tone

s an

d so

il sh

ould

em

bed

an a

dditi

onal

por

tion

of t

he p

last

ic a

t th

e to

p.

-

Use

of

Soil-

Cem

ent:

Ste

ps f

or s

oil-

cem

ent

plas

terin

g

m

Pre

pare

the

gro

und

as m

entio

ned

unde

r LD

PE li

ning

.

m

Lay

ers

of c

lay-

cem

ent

(7:1

pla

ster

) un

iform

ly li

ned

coat

aft

er c

oat

until

a t

hick

ness

of

3 cm

is a

ttai

ned

• LD

PE li

ning

and

Soi

l-Ce

men

t Pl

aste

r ar

e on

ly a

ppro

pria

te w

here

the

re is

no

tram

plin

g da

mag

e by

live

stoc

k an

d hu

man

Tool

sCo

nstr

ucti

on p

erio

d

• D

iggi

ng o

f th

e po

nd is

pr

efer

red

whe

n th

e so

il is

not

to

o dr

y an

d no

t to

o w

et f

or

ea

sy s

oil w

ork.

• St

one

wor

k an

y tim

e w

hen

la

bor

is a

vaila

ble.

Mai

nten

ance

Prec

auti

ons

Scop

e (S

ite

for

appl

icat

ion)

• Re

gula

rly

mai

ntai

n th

e lin

ing

in t

he c

hann

el a

nd

po

nd t

o re

duce

see

page

loss

.

• Re

gula

rly

rem

ove

sedi

men

t de

posi

ted

in t

he

ch

anne

ls a

nd p

ond.

Avo

id s

ites

:

• Le

ss t

han

50 m

ups

lope

fro

m a

hou

se

• W

here

the

re a

re s

lope

mov

emen

t, s

ubsi

denc

e, la

nd s

lidin

g or

gu

llyin

g (w

hich

may

aff

ect

if ex

tend

ed)

the

area

bel

ow;

• W

here

val

ley

side

is n

ot s

tabl

e to

hol

d st

andi

ng w

ater

;

• A

t th

e to

e of

the

slo

pe, w

here

inst

abili

ty o

f th

e sl

ope

may

in

crea

se;

• Cl

ose

to a

clif

f, w

here

slo

pe-f

ailu

re m

ay o

ccur

due

to

seep

age

or

w

ater

pre

ssur

e;

• Co

nstr

uctio

n of

new

pon

d or

impr

ovem

ent

of o

ld p

onds

• La

nd u

se im

prov

emen

t (c

onse

rvat

ion

plan

tatio

n, d

egra

ded

land

re

habi

litat

ion,

gra

ss p

lant

ing)

and

ero

sion

con

trol

mea

sure

s su

ch

as

mic

ro-g

ully

plu

ggin

g (f

asci

ne, p

alis

ades

, wat

tlin

g, b

rush

la

yeri

ng, b

rush

woo

d ch

eck

dam

) in

the

cat

ch a

rea.

• W

ater

har

vest

ing

• Co

nstr

uctio

n of

con

veya

nce

syst

em (

inle

ts a

nd o

utle

ts)

• Pr

otec

tion

of t

he p

ond

Refe

renc

es:-

DSC

, 199

2, F

AO

and

IIRR

, 199

5. S

thap

it, K

. M. a

nd S

hash

indr

a La

l, U

npub

lishe

d. S

CWM

C, 2

001,

DSC

WM

200

4.


Annex 5. List of Commonly Used Species

Local Name Botanical Name Botanical Name Local Name

Amala Emblica officinalis Acacia arabica Babul

Amliso Thysanolaena maxima Acacia catechu Khair

Arare Acacia pennata Acacia pennata Arare

Assuro Adhatoda vasica Adhatoda vasica Assuro

Babiyo Eulaliopsis binata Agave Americana Ketuki

Babul Acacia arabica Albizia lebbeck Kalo siris

Badaam (ground nut) Arachis glabarata Albizia procera Siris

Badahar Artocarpus lakoocha Alnus nepalensis Utis

Bains Salix tetrasperma Alnus nepalensis Utis

Bakaino Melia azedarach Arachis glabarata Badaam (ground nut)

Bayer Zizyphus mauritiana Artocarpus lakoocha Badahar

Bedulo Zizyphus jujube Arundinaria intermedia Nigalo

Bhatwasi Flemingia macrophylla Arundo clonax Narkat

Bhimal Grewia oppositifolia Arunduella nepalensis Phurke

Bhimal Grewia optiva Bambusa balcooa (Dhanu) Dhanu bans

Bhuletro Butea minor Bambusa nutans / cupalata Mal bans

Bihaya / Saruwa Ipomoea fistulosa Bassia butyracea Chyuri

Casuarina Casuarina Bauhinia purpurea Tanki

Centipede grass Centipede grass Bauhinia veriegata Koiralo

Champ Michelia champaca Brassaiopisi hainla Chuletro

Chilaune Schima wallichii Butea minor Bhuletro

Chuletro Brassaiopisi hainla Cajanus cajan Rahar

Chyuri Bassia butyracea Casuarina Casuarina

Dabdabe Garuga pinnata Centipede grass Centipede grass

Desmodium Desmodium rensonii Chamaecrista rotundifolia

Dhaincha Sesbania grandiflora Choerospondias axillaris Lapsi

Dhanu bans Bambusa balcooa (Dhanu) Colquhounia coccinea Namdi phul

Dhonde Neyraudia reynaudiana Cymbopogon microtheca Khar

Dubo Cynodon dactylon Cynodon dactylon Dubo

Dudhilo Ficus nemoralis D. Hookeri (kalo) Kalo

Faledo / Phaledo Erythrina arborescenes Dalbergia sissoo Sisso

Ghangharu Pyracantha crenulata Dendrocalamus hamltonii Tama bans

Gideri Premna spp. Desmanthus virgatus

Gliricidia Gliricidia sepium Desmodium rensonii Desmodium

Gogan Saurauia napaulensis Dismanthus

Golainchi Plumeria acuminata Drepanostachyum intermedium Tite nigalo bans

Ipil ipil Leucaena leucocephala Duranta repens Nilkada

Ipil-Ipil Leucaena leucocephala Emblica officinalis Amala

Kabro Ficus lacor Erythrina arborescenes Faledo / Phaledo

Kalo D. Hookeri (kalo) Eulaliopsis binata Babiyo

Kalo siris Albizia lebbeck Euphorbia royleana Siuli

Kanda phul Lantana camara Ficus glaberrima Pakhuri


Local Name Botanical Name Botanical Name Local Name

Kans Saccharum spontaneum Ficus lacor Kabro

Katara khar Themeda species Ficus nemoralis Dudhilo

Ketuki Agave Americana Ficus religiosa Pipal

Khair Acacia catechu Ficus roxburghii Nimaro

Khanyu Ficus semicordata Ficus semicordata Khanyu

Khar Cymbopogon microtheca Flemingia macrophylla Bhatwasi

Khirro Sepium insegne Fraxinus floribunda Lankuri

Khus Vetiveria lawsoni Garuga pinnata Dabdabe

Kimbu Morus alba Gliricidia sepium Gliricidia

Koiralo Bauhinia veriegata Grewia oppositifolia Bhimal

Kutmiro Litsea monopetala Grewia optiva Bhimal

Lahare papal Populus deltoids Himalayacalamus hookerianus Padang bans

Laliguras Rhododendron arboreum Ipomoea fistulosa Bihaya / Saruwa

Lankuri Fraxinus floribunda Ipomoea fistulosa Saruwa/Bihaya

Lapsi Choerospondias axillaris Jatropha curcas Sajiwan

Mal bans Bambusa nutans / cupalata Lantana camara Kanda phul

Namdi phul Colquhounia coccinea Leucaena leucocephala Ipil ipil

Napier Pennisatum purpureum Leucaena leucocephala Ipil-Ipil

Narkat Arundo clonax Litsea monopetala Kutmiro

Nigalo Arundinaria intermedia Melia azedarach Bakaino

Nilkada Duranta repens Michelia champaca Champ

Nimaro Ficus roxburghii Morus alba Kimbu

Padang bans Himalayacalamus hookerianus Neyraudia arundinacea Sito

Painyu Prunus cerasoides Neyraudia reynaudiana Dhonde

Pakhuri Ficus glaberrima Paspalum Paspalum

Paspalum Paspalum Pennisatum purpureum Napier

Phurke Arunduella nepalensis Pinus roxburghii Sallo

Pipal Ficus religiosa Plumeria acuminata Golainchi

Rahar Cajanus cajan Populus deltoids Lahare papal

Sajiwan Jatropha curcas Premna spp. Gideri

Sallo Pinus roxburghii Prunus cerasoides Painyu

Saruwa/Bihaya Ipomoea fistulosa Pyracantha crenulata Ghangharu

Sesbania Sesbania Rhododendron arboreum Laliguras

Simali Vitex negundo Saccharum spontaneum Kans

Siris Albizia procera Salix tetrasperma Bains

Sisso Dalbergia sissoo Saurauia napaulensis Gogan

Sito Neyraudia arundinacea Schima wallichii Chilaune

Siuli Euphorbia royleana Sepium insegne Khirro

Stylo-184 Stylo-184 Sesbania Sesbania

Tama bans Dendrocalamus hamltonii Sesbania grandiflora Dhaincha

Tanki Bauhinia purpurea Stylo-184 Stylo-184

Tite nigalo bans Drepanostachyum intermedium Tephrosia candida Tephrosia

Utis Alnus nepalensis Themeda species Katara khar

Utis Alnus nepalensis Thysanolaena maxima Amliso

Source: DSCWM 2004.


Annex 6. Proposed Training Module for Capacity Building in Landslide Treatment

Rationale Landslides are common in the mountainous landscape of Nepal, especially with heavy

monsoon rainfall. Landslides take lives and cause damage to livelihoods, settlements,

development infrastructure, agricultural fields, and forests. Landslide treatment is a major

task carried out every year to protect property and lives. Therefore, field professionals

need to understand the mechanisms of landslide and have skills in designing conservation

measures to treat landslides.

Objectives Enable participants to:

• Understand the concepts/mechanism/approaches of landslide treatment.

• Identify the problems and map the landslide based on the problems.

• Know about different techniques used to treat landslides

• Carry out surveying for landslide treatment

• Design different necessary conservation techniques to use to treat landslide.

By the end of the training

participants will be able to:

• Explain problems, causes, and mechanisms of the landslide.

• Carry out required mapping and surveying for landslide treatment.

• Explain different techniques applied for landslide treatment.

• Design necessary conservation measures for landslide treatment.

Target group All professionals designing and implementing landslide treatment

Prerequisites Trainees working or need to work in the field of soil conservation and watershed

management. Knowledge on mathematic and basic surveying would be beneficial.

Field/Lab work: 6 days of field and practical work in carrying out the survey, design, and presentation

Duration 2 weeks of working days

Venue/Responsibility The training is a residential training to focus on practical exercise after the mentioned

training period.

Remarks Training venue will be conveniently selected so that a real case can be surveyed and the

landslide treatment can be designed

Proposed training schedule is given below.


Day

08:3

0-09

:00

09:0

0-10

:30

10:3

0-10

:45

10:4

5-12

:15

12:1

5-13

:15

13:1

5-14

:45

14:4

5-15

:00

15:0

0-16

:30

1Re

gist

rati

onO

peni

ng, I

ntro

duct

ion

of

part

icip

ants

, exp

ecta

tion

colle

ctio

n, h

ighl

ight

the

tra

inin

g

mod

ule

and

logi

stic

brie

fing

Brea

k1.

Und

erst

andi

ng n

atur

e la

w in

Wat

er In

duce

d W

ater

Dis

aste

r

Man

agem

ent

Lunc

h2.

Intr

oduc

tion

to

Inte

grat

ed W

ater

shed

Man

agem

ent

and

Low

cost

soi

l con

serv

atio

n

tech

niqu

es

Brea

k3.

Intr

oduc

tion

to S

oil E

rosi

on

incl

udin

g la

ndsl

ide

and

its

mec

hani

sm

2Re

view

4. A

naly

sis

of u

rgen

cy a

nd

reco

mm

enda

tion

for

land

slid

e

trea

tmen

t

Brea

k4a

. Pra

ctic

al e

xerc

ise

on

Land

slid

e U

rgen

cy a

nd

Reco

mm

enda

tion

for

Trea

tmen

t A

naly

sis

Lunc

h5.

Und

erst

andi

ng

Geo

logy

with

res

pect

to

Land

slid

es

Brea

k5a

. Und

erst

andi

ng G

eolo

gy

with

res

pect

to

Land

slid

es

cont

inue

d.

3Re

view

6. C

onse

rvat

ion

tech

niqu

es: G

rass

and

Bam

boo

plan

ting

Brea

k7.

Con

serv

atio

n te

chni

ques

:

Cons

erva

tion

plan

tatio

n

Lunc

h8.

Con

serv

atio

n

tech

niqu

es: M

ulch

ing

and

Buff

er s

trip

Brea

k9.

Con

serv

atio

n te

chni

ques

:

Fasc

ine

and

Palis

ade

4Re

view

10. C

onse

rvat

ion

tech

niqu

es: B

rush

laye

ring

and

wat

tlin

g

Brea

k11

. Con

serv

atio

n te

chni

ques

:

Rip-

rap

and

wat

erw

ays

Lunc

h12

. Bas

ic S

urve

ying

and

Fam

iliar

izat

ion

with

Clin

o-co

mpa

ss

Brea

k12

a. F

ield

exe

rcis

e on

surv

eyin

g: P

rofil

e an

d cr

oss

sect

ion

5Re

view

13 C

onse

rvat

ion

tech

niqu

es:

Gab

ion

bols

ter

and

Reta

inin

g w

all

Brea

k13

Con

serv

atio

n te

chni

ques

:

Reta

inin

g w

all c

ontin

ued.

Lunc

h13

a. F

ield

sur

veyi

ng f

or r

etai

ning

wal

l

6Re

view

14 R

unof

f ca

lcul

atio

nBr

eak

14a

Prac

tical

exe

rcis

e on

run

off

calc

ulat

ion

Lunc

h13

b Pr

actic

al e

xerc

ise

on d

esig

ning

ret

aini

ng w

all

7D

ay O

ff

8Re

view

13c

Pres

enta

tion

of t

he r

etai

ning

wal

l des

ign

Brea

k15

Intr

oduc

tion

to C

heck

dam

Lunc

h15

a Fi

eld

surv

eyin

g fo

r ch

eck

dam

9Re

view

16 W

ater

Har

vest

ing

Pond

Brea

k15

b Pr

actic

al e

xerc

ise

on c

heck

dam

10Re

view

15c

Pres

enta

tion

of t

he c

heck

dam

desi

gn

Brea

k16

a Pr

actic

al e

xerc

ise

on t

he w

ater

har

vest

ing

pond

Brea

k16

b Pr

esen

tatio

n on

Cons

erva

tion

Pond

11Re

view

17 4

Ste

ps in

Des

igni

ng L

ands

lide

Trea

tmen

t an

d M

itiga

tion

Mea

sure

s

Brea

k17

a Fi

eld

surv

eyin

g fo

r La

ndsl

ide

trea

tmen

t (R

eal C

ase

Stud

y)

12Re

view

Fiel

d su

rvey

ing

for

Land

slid

e tr

eatm

ent

if re

quire

d or

Pra

ctic

al e

xerc

ise

on

desi

gnin

g la

ndsl

ide

trea

tmen

t (R

eal C

ase

Stud

y)

Lunc

hPr

actic

al e

xerc

ise

on d

esig

ning

land

slid

e tr

eatm

ent

(Rea

l Cas

e St

udy-

4

Step

s)

13Re

view

Pres

enta

tion

on la

ndsl

ide

desi

gnTr

aini

ng E

valu

atio

nCl

osin

g an

d Ce

rtifi

cate

Dis

trib

utio

n

Clas

s ro

om

Fi

eld

wor

k

Prac

tical

Pr

esen

tatio

n

Trai

ning

eva

luat

ion,

ope

ning

, and

clo

sing

Off

Prop

osed

Ten

tati

ve T

rain

ing

Sche

dule


Annex 7. Landslide Inventory

Landslide is a general term used to describe a mass of

material that has slipped downhill under the influence

of gravity, frequently occurring when the material is

saturated with water . Landslides do not occur randomly or

by chance. A landslide is a dynamic process. Its occurrence

and stability is the result of the interplay of physical

processes, and mechanical laws controlling the stability or

failure of a slope .

The Gorkha Earthquake 2015 either enlarged old landslides

or triggered new landslides, leading to massive destruction

in districts affected by the earthquake. Immediately

after the Gorkha Earthquake, the Department of Soil

Conservation and Watershed Management (DSCWM) began

initiatives to protect affected communities by developing

infrastructure to mitigate the earthquake induced or

enlarged landslide hazards, and to prevent further

destruction as much as possible.

In consultation with other related Government

organizations and with the support of Nepal’s

development partners, DSCWM organized a consultation

workshop on September 28th – 29th, 2015 on the

inventory, hazard assessment, and treatment and

mitigation of landslides. The DSCWM led the consultation

workshop with support from ICIMOD, UNEP, UNDP, IUCN,

FAO, and WWF.

Objectives

Landslide inventory sheet is designed to collect

information on landslides essential for policy formulation,

strategy guidance, precautionary measures and treatment

of landslides in order to minimize the adverse effects and

impacts of landslides on lives and property.

Key features of the inventory: -

• Simple to use by practitioners especially agencies

engaged in landslide treatment and mitigation,

such as the Department of Soil Conservation and

Watershed Management and Department of Water

Induced Disaster Prevention. The inventory should be

compatible with easily accessible digital tools such as

Google Earth.

• The information used to analyze the urgency and

degree of recommendation for landslide treatment

should be consistent.

Key information included in the inventory fact sheet includes: -

• Where did the landslide occurred? Give the location of

and major land use associated with landslide

• How big is the landslide? Give the area of the

landslide.

• What type of landslide occured?

• What are the main causes? Specify the major factors

triggering or enlarging landslide.

• How often will it occur in the future? What is the

probability of its occurrence again?

• What will it damage? Where? What are the

elements at risk (Settlements, national heritage,

roads, irrigation, drinking water supply schemes,

hydropower, land use).

• What is the scale of damage? Quantify the degree of

damage to the element at risk.

• How easily it can be treated? What is the

recommendation for the landslide’s treatment? What

is the type of landslide in term of its treatability.

• What is the potential of the landslide blocking the

river?

The proposed fact sheet for landslide inventory is given in

Annex 7 Table 1.

10 Soil Conservation Society of America-1982, Resource Conservation Glossary Third edition.

11 Guzzetti, F., Mondini, A. C., Cardinali, M., Fiorucci, F., Santangelo, M. and Chang K.-T. 2012. Landslide inventory maps: New tools for an

old problem. Earth-Science Reviews, 112: 42–66.


Annex 7. Table 1. Landslide Inventory Fact Sheet

Landslide Index No: District Code + VDC Code + Landslide Code (All are 2 digit code)

BASIC INFORMATIONLocation (District/VDC/Ward): ………………………………………….….

Coordinate at the bottom of the landslide:

Coordinate:

Bounding Max:

Bounding Min:

Major Land use associated with landslide:

Forest Agriculture

Grazing Settlement

Approximate Area (sq. m.): .........................

Aspect: ………………

Elevation: Max. …….m. Min. ………in m.

History: When it was initiated?

Type of Landslides classification by Cruden and Varnes (1996).(Tick in appropriate box)

Movement type

Slide Flow

Mat

eria

l inv

olve

d Ea

rth Earth

Translational Slide Earth Flow

Rotational Slide

Complex Slide

Earth

Translational Slide Channelized flow

Rotational Slide Open slope debris flow

Complex Slide

Rock

Translational Slide

Rotational Slide

Complex Slide

Shallow seated: Deep seated:

Major Factors Triggering / Enlarging Landslide (Tick in Appropriate type):

Toe cutting, Heavy rain, Steep slope

Lack of water management, Heavy rain, Steep slope

Cracked rocks, Heavy rain, Steep slope, Earthquake

Probability of Occurrence Quantification of damage to the element at risk

High Medium Low High Medium Low

Geology:

Type of Landslide in term of Treatability (Tick in Appropriate type):

Easily Treatable Moderately Treatable Difficultly Treatable

Element at Risk

Settlement / National Heritage / Lives

Village Name: ………………………………………. National Heritage Name: ……………………………………….

No of House affected No of People displaced No. of People killed

Road

Road Type (Tick in Appropriate type)

Dirt road Gravel road Asphalt road

Length of Road affected in meters

Irrigation

Irrigation Type (Tick in Appropriate type) Command area in ha.

Community Multi community Multi VDC Affected Length in meters

Drinking water supply scheme

Drinking water supply Type (Tick in Appropriate type) No. of User Households

Community Multi community Multi VDC Length in meters

Hydropower (Tick in Appropriate type)

Intake: Dam: Tunnel Station: Stilling basin:

Land use

Agriculture National Forests Community Forests Pasture lands / Shrub / Grass

Landslides Blocking Stream / River (Tick Appropriate type)

Name Designation Signature Date

None (no signs of blockage of rivers)

Partially (partially blocked the river)

Complete (completely blocked the river, and still blocking)

Complete and broken through (blocked the river but later broken through)


Brief description of type of movement

Type of Movement Description

Slides

Rotational

Translational

Slope movement caused by shear failure of distinct surface.

Movement is approximately on circular surface of failure. It may be single or multiple rotational

failure surface.

Movement is approximately on planar surface failure.

Flows Rapid movements of vicious fluid. Slip surfaces are almost absent.

Complex Combination of two or more principal types of movement.

Earth Flow Rapid movements earth materials as vicious fluid.

Channelized debris flow Rapid movement of debris as vicious fluid in channel.

Open slope debris flow Rapid movement of debris as vicious fluid in slope without confined channel.

Debris: Mixture of loose soil, rock, and organic matter. Debris

consists of <50% fine materials.

Earth: Mixture of loose soil, stones, and organic matter. Earth

consists of > 50% fine materials.

Type of landslide:

Not considered for treatment: Mass movement, such as

raiser failure in the agriculture land that farmers will likely

rehabilitate as a part of cultivation, will not be considered for

treatment. Landslide not affecting livelihoods or settlements

including educational centers and livelihood based property

such as agricultural fields, trail and roads, irrigation canals,

will not be considered for treatment. Such landslides are left

for nature to treat.

Landslide is divided into shallow seated and deep seated.

Shallow seated: Movement of earth mass disturbing up

to C horizons. This type of landslide is treatable with the

bioengineering techniques and with reasonable resources

and time frame and affecting livelihood based namely

agriculture, forest and grazing land and settlement. No

bedrock are disturbed or moved.

Deep seated: Movement has occurred resulting cracks in

bedrock and bedrock movement. Treatment of such landslide

requires big structures, especially reinforced concrete

structures and grouting, at the cost of huge resources

and time. Such landslides are treated if they are affecting

nationally important structures, such as highways, hydro-

power, and large settlements.

Shallow seated: A, B, and C Horizons Disturbed. Treatable

within reasonable timeframe and the scope of bio-

engineering techniques and resources.

Deep seated: Geological failure (Crack and slides bed

rocks) Required big structures (Concrete) and huge

resources, affecting nationally important structures.

Treatability Status Criteria

Easily Treatable with bio-engineering measures within 2 years

Moderately Treatable with some engineering structures and bio-engineering measures within 5 years

Difficultly Requiring many big engineering structures and requiring more than 5 years


Annex 8. Format for Documentation of the Lessons Learned

Documentation of lesson learned start with filling the landslide inventory fact sheet given in Annex 7, Table 1.

Analysis for urgency and recommendation for treatment will be carried out and documented in as per Annex 8, and Tables

1 and 2 of the main document.

List the techniques applied.

S.N. Name of the

techniques

Specify the

key problems

the technique

is applied for

Steps in

applying the

techniques

Change in steps

if the techniques

is to be applied

again

Does the techniques

help in addressing

key problem (Rank

the status: Very Good,

Good, Moderate, Low,

Very Low )

Specify

adverse effect

the techniques

if any

Document the pictures of each technique (With time series if possible until the landslide is no longer threatening)

Technique applied:

Before After

Overall picture of the landslide

Before After

Recommended Survey/Design/Practical Tips or Considerations: -

Department of Soil Conservation and Watershed ManagementKathmandu, June 2016

(Asar 2073)


Department of Soil Conservation and Watershed ManagementG.P.O. BOX 4719, Babar Mahal, Kathmandu, NepalT: 977-1-4220828/4220857 | F: 977-1-4221067

E: [email protected]/[email protected]: www.dscwm.gov.np

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