بسم اهللا الرحمن الرحیمSudan Academy of Science

Engineering Researches & Industrial Technologies Council

Water Harvesting and Artificial Recharge in Al Biteira, South Kurdufan State –Sudan.

By

Dafalla Siddig Dafalla Wadi B. Sc. (Honours.) in geology

Al Neelain University (2007)

Supervisor: Dr. Ibrahim A. Malik

February, 2013

A thesis Submitted to the Sudan Academy of Sciences in Fulfillment of the Requirements for the Degree of Master of Science in Engineering

Geology

II

Water Harvesting and Artificial Recharge in Al Biteira, South Kurdufan State –Sudan.

By Dafalla Siddig Dafalla Wadi

Examination Committee

Examination Date: 14.02.2013

III

IV

DEDICATION

To my beloved Brother (KAMIL) memory, to his pure and chaste soul in

the highest heavens ……

Abstract

V

The investigated area extends over 2260 Km2, between latitudes 11º 30' N to 11º 50' N and

longitudes 31º 10' E to 31º 35' E. The study was aimed to provide rainwater harvesting solution

in both surface and subsurface storage using geological and geotechnical aspects.

From Geological point of view, Northeastern Nuba Mountains region represents one of the most

important basement complexes in Sudan. The area is underlain by high-grade gneisses and low-

grade meta-volcano-sedimentary sequence of the Nubian Arabian shield (both are intruded by

alkaline and post to anorogenic intrusions) and paleozoic sediments. Kabus Ophiolitic mélange

separates the two terrains as a suture zone demarking an old subduction zone.

Landsat images ETM+ color composite; Band 7, Band 4 and Band 2 in R G B respectively with

scale 1:200,000 which processed by ENVI 4.8 software, were used as base maps. Digital

Elevation Model (DEM) was used in Arc Hydro tool software, to delineate watershed; a

geometric network is constructed.

Structural analysis has been carried out to analyze number of structural data which were

collected during the study period. These data were in form of measurements taken from different

structural elements (foliation, lineation, fold axes, lineaments... etc). Through these data a

structural model was constructed to explain different phases of deformation, in this phase

STEREO NET® was used.

Soil texture tests on four proposed sites which selected based on watershed delineation results

was done. The mechanical (sieve) analysis was performed to determine the distribution of the

coarser, larger-sized particles. Hydrometer method was used to determine the distribution of the

finer particles. Materials are classified according to the ‘Unified Soil Classification’ system.

For the seepage tests; there was a simple test has been carried out to evaluate the sites. During

the site exploration, several soil-sampling test holes has been dug in the borrow pit areas, these

holes are done by hand.

Cross section of proposed dams, along their axis has been investigated by Global Mapper

software using Shuttle Radar Topographic Map (SRTM) data; to point out the possible dam

height to be constructed. The embankments Distances of each dam were calculated. Suitable

dam sites were selected.

VI

VII

الموجز إلى طول وخطي 11º 50'Nو 11º 30'N عرض خطي بین ،كلم مربع 2260 دراسة حواليال منطقةتغطي

31º 35' E 31وº 10' E . اجریت الدراسة بغرض ایجاد حلول لمشكلة المیاه متمثال في حصاد میاه

. والجیوتقنیة الجیولوجیة الجوانباالمطار و تخزینة في سدود سطحیة و تحت سطحیة باالعتماد على

في معقدات االساستمثل واحدة من أھم الشمالیة الشرقیة من وجھة نظر الجیولوجیا، منطقة جبال النوبة

و درجة التحول العالیة في االتجاه الغربي، و الصخور الرسوبیة ذ، ممثال في صخور النایس السودان

االثنین ( الدرع العربي النوبيو درجة تحول منخفضة في االتجاه الشرقي و ھي جزء من سلسة ذالبركانیة

فیوالیتي وھي یفصل بین النوعین خلیط كابوس اال). معا تعرضا لتدخالت ناریة قلویة بعد عملیة التجبل

. عبارة عن منطقة اندساس قدیمة

زرق في االلوان االحمر، االخضر و اال 2و 4، 7صور االقمار االصطناعیة ملونھ باحزمة استخدمت

كخرائط ENVI 4.8، و تمت معالجتھا بالبرنامج الحاسوبي 1:200000علي التوالي و بمقیاس رسم

لتحدید انظمة Arc Hydro toolرقمیة بالبرنامج الحاسوبي كما عولجت صور نموزج االرتفاعات ال. اساس

.تصریف المیاه في المنطقة

للمنطقة من المعلومات التي تم جمعھا خالل الدراسة الحقلیة، وھي عبارة عن تم تنفیذ التحلیل البنیوي

من خالل ). الخ ... ومحاور الطیات طالتورق والتخط(ھا من الظواھر التركیبیة المختلفة ذقراءات تمت اخ

تم استخدام البرنامج المرحلة ه، في ھذالمختلفة لشرح مراحل التشوه التركیبيھذه البیانات تم بناء النموذج

. Stereonet الحاسوبي

ت من اربعة مناطق مقترحة ذلتربة اخالمعرفة التوزیع الحجمي الحبیبي لعینات من إجراء اختبارات تم

تم ماالكبیرة الحجم، وك- لتحدید توزیع الجسیمات الخشنة )يمنخلال(؛ تم إجراء التحلیل المیكانیكي للسدود

.تصنیف التربة الموحد"المواد وفقا لنظام توصنف. لتحدید توزیع الجسیمات الدقیقة التحلیل المائي

عن طریق ختبار التربة ال حفروقد تم حفر عدة ،لالختبارات التسرب، تم استخدام اختبار بسیط لتقییم الموقع

. بالماء و قراءة زمن التسرب مأل الحفر المحفورة یدویا

الطولیة للردمیات باستخدام صور اتدراسة القطاعات التضاریسیة للمواقع المقترحة للسدود واالمتدادتم

.Global Mapper 13رادار اللتضاریسیة و التي تمت دراستھا بالبرنامج الحاسوبي

VIII

Acknowledgements

There are many people who have supported and provided information, ideas and procedures in

the collation of this thesis. Perhaps a major dilemma for me is the incorporation of sources of

information, which are better explained in the anonymous quote:

How about the many ideas and procedures that one picks up from discussion with colleagues?

After the passage of time, one can no longer remember who originated what idea. After the

passage of even more time, it seems to me that all of the really good ideas originated with me, a

proposition that I know is indefensible.

It becomes clearer with time that nothing is new, but people forget the original sources and

whether those sources were really original or were the result of slight modifications of other

people’s ideas. It is like the wheel. Nobody knows who conceived the idea, yet it is used

universally. So, credit must be given to those who have gone before me in this area.

My supervisor Dr. Ibrahim A. Malik of Al Neelain University has been supportive, invaluable

advices and guidance throughout and fruitful discussion during the study period.

My family has been supportive in assisting in many ways. My wife has typed a number of drafts.

My father and mother have supported me, whilst my brothers and sisters have done their bit in

other ways.

In the practical, I would like to thank all of those who have been instrumental in the completion

of this thesis. Some of these people (in no particular order) are: Police officer, Community

leader, School teachers and Public committee of Al Biteira Village.

IX

Contents DEDICATION ..................................................................................................................................... IV

Abstract ............................................................................................................................................... IV

VII.................................................................................................................................................... الموجز

Acknowledgements ........................................................................................................................... VIII

Contents ............................................................................................................................................... IX

List of figures ......................................................................................................................................XII

List of Tables .................................................................................................................................... XIII

List of plates...................................................................................................................................... XIV

List of abbreviation ........................................................................................................................... XV

CHAPTER ONE .................................................................................................................................... 2

INTRODUCTION ................................................................................................................................. 2

1.1 Location and Accessibility: ...................................................................................................... 2

1.2 Physiographical features ........................................................................................................... 2

1.2.1 Topography ...................................................................................................................... 2

1.2.2 Drainage system ............................................................................................................... 2

1.2.3 Climates and the Vegetation Cover ................................................................................... 2

1.3 Socio-Economic features .......................................................................................................... 5

1.4 present studies .......................................................................................................................... 7

1.4.1 Statement of the Problem .................................................................................................. 7

1.4.2 Objective of the study ....................................................................................................... 7

1.5 Methods of investigation .......................................................................................................... 8

1.5.1 Field work:........................................................................................................................ 8

1.5.2 Office work: ...................................................................................................................... 8

1.6 previous works ......................................................................................................................... 8

CHAPTER TWO................................................................................................................................. 11

GEOLOGICAL AND TECTONIC SETTING OF STUDY AREA ................................................... 11

2.1 Introduction ........................................................................................................................... 11

2.2 Stratigraphical succession....................................................................................................... 12

2.2.1 High-Grade Gneisses: ..................................................................................................... 12

2.2.2 Kabus Ophiolite Zone: .................................................................................................... 14

2.2.3 Low-Grade Volcanosedimentary Sequence: .................................................................... 15

2.2.4 Syn-tectonic Igneous Intrusions: ..................................................................................... 18

X

2.2.5 Superficial deposits ........................................................................................................ 19

2.3 Structures ............................................................................................................................... 19

2.3.1 Introduction: .................................................................................................................. 19

2.3.2 Primary structures: ......................................................................................................... 19

2.3.3 Major structures: ............................................................................................................ 20

2.4 Structural analysis: ................................................................................................................. 21

CHAPTER THREE............................................................................................................................. 25

APPLICATION OF GEOGRAPHICAL INFORMATION SYSTEM (GIS) IN WATERSHED DELINEATION .................................................................................................................................. 25

3.1 Overview of GIS Application ................................................................................................. 25

3.1.1 Mapping ......................................................................................................................... 25

3.1.2 Weighted overlay analysis .............................................................................................. 25

3.1.3 Watershed delineation .................................................................................................... 26

3.2 Objective ............................................................................................................................... 26

3.3 Terrain Preprocessing ............................................................................................................. 26

3.3.1 Digital Elevation Model (DEM)...................................................................................... 27

3.3.2 Fill Sinks ........................................................................................................................ 27

3.3.3 Flow Direction ............................................................................................................... 28

3.3.4 Flow Accumulation ........................................................................................................ 28

3.3.5 Stream Definition ........................................................................................................... 28

3.3.6 Stream Segmentation ...................................................................................................... 29

3.3.7 Catchment Grid Delineation ........................................................................................... 29

3.3.8 Catchment Polygon Processing ....................................................................................... 30

3.3.9 Drainage Line Processing ............................................................................................... 31

3.3.10 Adjoint Catchment Processing ........................................................................................ 31

3.3.11 Drainage Point Processing .............................................................................................. 31

3.3.12 Watershed processing ..................................................................................................... 31

CHAPTER FOUR ............................................................................................................................... 35

WATER HARVESTING TECHNIQUES .......................................................................................... 35

4.1 Introduction ........................................................................................................................... 35

4.2 Current situation of water availability ..................................................................................... 36

4.2.1 surface water .................................................................................................................. 36

XI

4.2.2 Groundwater .................................................................................................................. 36

4.3 Planning ................................................................................................................................. 36

4.3.1 Assessing water needs .................................................................................................... 36

4.3.2 Planning of water supplies .............................................................................................. 37

4.3.3 Assessment of catchment yield ....................................................................................... 37

4.3.4 Dam site selection .......................................................................................................... 41

4.3.5 Dam storage size ............................................................................................................ 42

4.4 Investigation .......................................................................................................................... 44

4.4.1 Soil testing ..................................................................................................................... 45

4.4.2 Site selection criteria ...................................................................................................... 47

4.5 Design ................................................................................................................................... 61

4.5.1 Items that need to be considered ..................................................................................... 62

4.5.2 Outlet structures ............................................................................................................. 72

4.6 Water management ................................................................................................................ 75

4.7 Environmental significance of the dam project ....................................................................... 76

4.7.1 Positive Impacts ............................................................................................................. 76

4.7.2 Adverse Impacts ............................................................................................................. 77

4.8 Sedimentation ........................................................................................................................ 78

4.8.1 Introduction .................................................................................................................... 78

4.8.2 Main impacts of reservoirs sedimentation ....................................................................... 79

4.8.3 Reservoir sedimentation management ............................................................................. 81

4.8.4 Siltation may be a key problem of many reservoirs ......................................................... 83

CHAPTER FIVE ................................................................................................................................. 85

CONCLUSION AND RECOMMENDATION ................................................................................... 85

5.1 Conclusion ............................................................................................................................. 85

5.2 Recommendation ................................................................................................................... 86

REFERENCES...................................................................................................................................... 87

Appendix A: ......................................................................................................................................... 93

Appendix B: ......................................................................................................................................... 96

Appendix C ........................................................................................................................................ 105

Appendix D ........................................................................................................................................ 116

XII

List of figures Fig. 1.1 Location map of study area................................................................................................3

Fig. 1.2 Digital elevation model and topographic cross section......................................................4

Fig. 1.3 Drainage pattern of Nuba Mountains.................................................................................5

Fig. 1.4 Rashad monthly rainfalls....................................................................................................6

Fig. 1.5 South Kurdufan vegetation and rainfall prospective..........................................................6

Fig. 2.1 Regional geological map of North-eastern Nuba Mountains...........................................13

Fig. 2.2 Stereographic projection of study area.............................................................................22

Fig. 2.3 Stress and Strain ellipsoids...............................................................................................23

Fig. 2.4 Lineaments of study area…………………………………………………………..……23

Fig. 3.1 Digital elevation model....................................................................................................27

Fig. 3.2 filled sink image...............................................................................................................28

Fig. 3.3 Flow direction...................................................................................................................28

Fig. 3.4 Flow accumulation...........................................................................................................29

Fig. 3.5 Stream definition..............................................................................................................29

Fig. 3.6 Stream segmentation.........................................................................................................30

Fig. 3.7 Catchment grid delineation...............................................................................................30

Fig. 3.8 Catchment polygon processing.........................................................................................30

Fig. 3.9 Catchment polygon with drainage line processing...........................................................32

Fig. 3.10 Adjoint catchment processing with drainage..................................................................32

Fig. 3.11 drainage point processing...............................................................................................32

Fig. 3.12 Stream order...................................................................................................................32

Fig. 3.13 Watershed and drainage lines.........................................................................................33

Fig. 4.1 Water losses and needs.....................................................................................................43

Fig. 4.2 Depth of test holes a long centre –line.............................................................................46

XIII

Fig. 4.3 watersheds and proposed dam sites..................................................................................49

Fig. 4.4 Textural classification chart..............................................................................................51

Fig. 4.5 grains size analysis curve.................................................................................................57

Fig. 4.6 Rose diagram of foliations dip..........................................................................................61

Fig. 4.7 Cross section and elevation view......................................................................................62

Fig. 4.8 Zoned dam with treatment of seepage..............................................................................65

Fig. 4.9 Cross section of Kabus proposed dam site.......................................................................67

Fig. 4.10 Cross section of Al Ufaynah proposed dam site.............................................................67

Fig. 4.11 Cross section of Rugut proposed dam site......................................................................67

Fig.4.12 Cross section of Kurunn proposed dam site....................................................................68

Fig. 4.13 Wave action....................................................................................................................69

Fig. 4.14 wave actions based on fetch distance across storage......................................................69

Fig. 4.15 Typical rock –beaching..................................................................................................72

Fig. 4.16 Sketch of spillway..........................................................................................................73

Fig. 4.17 Spillway crosses section.................................................................................................73

Fig. 4.18 Pipeline through embankment........................................................................................75

Fig. 4.19 Schematic flow diagram for raw water……………………………………………….76

Fig. 4.20 Plan view and vertical cross section for dammed watershed………………………....81

List of Tables Table 4.1 Storage period................................................................................................................39

Table 4.2 Yield from natural catchments.......................................................................................40

Table 4.3 Location of proposed dam sites.....................................................................................48

Table 4.4 Soil texture classes.........................................................................................................50

Table 4.5 Values of effective depth...............................................................................................55

Table 4.6 Values of K for use in equation for computing diameter..............................................56

XIV

Table 4.7 Temperature correction factors......................................................................................56

Table 4.8 Correction factors a for unit weight of solids................................................................56

Table 4.9 Sieve analysis.................................................................................................................57

Table 4.10 Hydrometer analysis....................................................................................................57

Table 4.11 Soil texture test............................................................................................................58

Table 4.12 Unified soil classification............................................................................................59

Table 4.13 Guide to site selection based on seepage loss..............................................................60

Table 4.14 Seepage test..................................................................................................................60

Table 4.15 Height to crest width....................................................................................................66

Table 4.16 proposed dam’s height, crest width, embankment length, fetch distance and freeboard........................................................................................................................................66

Table 4.17 freeboard values for various fetches............................................................................70

Table 4.18 Sediments yield data from reservoir surveys ………………………………………79

List of plates Plate 2.1 Photomicrograph of Metagabbro....................................................................................14

Plate 2.2 Photomicrograph of Quartzite.........................................................................................11

Plate 2.3 Photomicrograph of pyritefirous Chlorite Schist............................................................16

Plate 2.4 Photomicrograph of Quartz vein lets in Graphitic Schist...............................................17

Plate 2.5 Photomicrograph of Marble............................................................................................18

Plate 4.1 Soil Test hole.................................................................................................................47

Plate 4.2 Embankment material.....................................................................................................47

Plate 4.3 Soil texture test equipment..............................................................................................52

XV

List of abbreviation

Cc: Calcite

CDWR: California Department of Water Resources.

DEM: Digital Elevation Model.

ENVI: Environmental Visualizing Imagery.

ETM: Thematic Enhanced Mapper.

GIS: Geographical Information System.

Gr: Graphite.

Pyt: Pyrite.

Pyx: Pyroxene.

Qtz: Quartz.

RGB: Red, Green and Blue.

SCA: Soil Conservation Authority.

Srp: Serpentine.

SRW: Southern Rural Water, Victoria –Australia.

SWAT: Soil and Water Analysis Tool.

USA: United States of America.

USDA: United States Department of Agriculture.

WAWA: Water Authority of Western Australia.

CHAPTER ONE

INTRODUCTION

2

CHAPTER ONE INTRODUCTION

1.1 Location and Accessibility: The study area lies in the northeastern part of the Nuba Mountains which extends in parts of

southern Kurdufan state (fig. 1-1). The study area extends between latitudes (11º 30' N to 11º 50'

N) and longitudes (31º 10' E to 31º 35' E) and covers an area of about 2260Km2 (fig. 1.1). The

study area is accessible from Khartoum via two ways either by the asphalt road from Khartoum

to Kosti, and then through the spur roads to the different parts of the area, or by the rail way

Khartoum –Sinnar –Kosti, and then through the spur roads to the area. The study area is quite

inaccessible in the rainy season with the exception of few roads that are possible with great

difficulty.

1.2 Physiographical features 1.2.1 Topography The studied area lies in the north- eastern edge of a gentle topographical swell in the central plain

of the Sudan and it represented in different topographic terranes varying from hilly to peniplains

(fig. 1.2) and it rises to a height of 500m above mean sea level.

1.2.2 Drainage system The Nuba Mountains are traversed by a strong system of regional radial drainage system (fig.

1.3) and surrounded by large graben like structures filled with thick sediments up to 4,500m

which constitutes water aquifers and/or oil bearing reservoirs. The water courses are dry for most

of the year but carry considerable run-off during the rainy season when up to 800mm is

precipitated. In spite of this some natural depressions hold considerable amount of water for the

whole year and being used as permanent source of drinking water.

1.2.3 Climates and the Vegetation Cover The Nuba Mountains are characterized by Savannah climate ranging from poor Savannah in the

northern part with long dry season to rich Savannah in the southern part of the region with long

rainy season (April - November) and considerable amount of rainfall reach 800mm (fig. 1.4).

Rainfall is usually evenly distributed all over the area. The last prolonged drought continued

until 1987. Then heavy rains were received in 1988, 2001, 2007, 2008 and 2012.

Sometimes two-week dry spells in July and August take place. However, this usually does not

affect the crop production.

3

Fig. 1.1: Location map of study area

4

Fig. 1.2: Drainage, Digital Elevation model (DEM) and Topographic Cross section (A –B) of the study

area

5

Rainfall is highly variable from one rainy month to another. The variability of monthly rainfall

during a single rainy season ranges from 37% to 70%. According to these deviations, the range

of annual rainfall is hence 465-991mm in Kadugli, 456-1004mm in Rashad .The summer is

generally hot with an average temperature of about 30Cº (Abdalla and Fota, 2001).

Fig. 1.3: Drainage pattern map of Nuba Mountains

The vegetations include moderate to tall grass cover interspersed by variable Thorny Acacia

trees that mainly cluster on the topographic surfaces of the outcrops, and concentrate along the

drainage channels and around the natural pools. The vegetation covers get denser and taller

southwards where forests of rich Savannah climate are encountered (fig. 1.5).

1.3 Socio-Economic features The region is mainly inhabited by the Nuba tribes mixed with some Arabs especially in the

Northeastern territories. The inhabitants are mainly engaged with the seasonal rain-fed

cultivation and rearing of the domestic animals such as cattle, Sheep and goats. Donkeys and

6

Camels are kept and routinely used for transporting water from wells or Hafirs and other

transportations purposes.

Fig. 1.4: Rashad monthly mean rainfall (after Abdalla and fota, 2001).

Fig.1.5: South Kurdufan Vegetation and rainfall prospective (after Sudan metrological Authority, 2011)

7

1.4 present studies 1.4.1 Statement of the Problem

Nuba Mountains area receives annually about 800 mm of rainfall from April to November,

making flooding in many areas, with wide streams as Khor el awai close to Abu Gibeiha, but

unfortunately, in spite of that, at the end of the rainy season (April to November) it become so

difficult to get water just for drinking rather than other purpose like irrigation.

The area of Nuba Mountains is suffering from lack of water for both domestic and irrigation

demands, due to:

Shallow basement complex (limited groundwater aquifers).

High inclination of mountains slope towards the White Nile (causes the whole rainfall

received flow to White Nile).

The area under investigation is located very far from the Nile system.

In this regard rain water harvesting should be done to provide enough water for drinking and

irrigation to people over there, to get a bright life, because water displays the base of everything.

1.4.2 Objective of the study

The aim of present investigation is directed to provide rainwater harvesting solution in both

surface and subsurface storage in Northeast Nuba mountains area using geotechnical aspects as

follows:

To identify and analyze rainwater harvesting methods.

Analyze the significance for rainwater harvesting in populated areas in Northeast Nuba

Mountains.

Develop a solution for rainwater harvesting solution for a typical surface storage and

artificial recharge.

Utilize programming and visualization to assess the efficiency of the solution and its

details.

Sites investigation for constructing dams for surface storage.

Structural analysis for artificial recharge to alluvial aquifer (subsurface storage).

8

1.5 Methods of investigation 1.5.1 Field work:

This work was conducted in the period from 26th November 2010 to 26th December 2011.

Three field trips were carried out in this period with total 34 days.

Throughout the regional investigations Landsat images ETM+ color composite; Band 7, Band 4

and Band 2 in R G B respectively with scale 1:200,000 were used as base maps. The collected

field data included: rock and soil samples, structural measurements, and photographical

documentation. Seepage tests were carried out during the field work. Field data collecting is

needful for any successful geological work.

1.5.2 Office work:

For petrographical study, about 25 thin sections have been prepared and studied under the

polarized microscope to identify the mineral compositions and microstructures of the rocks.

Several computer software packages were used for processing, representing, and interpreting the

collected field data: ENVI® 4.8 was used to process and enhance the appearance of the digital

satellite images for more interpretability, and better emphasizing of the geological and structural

features. The Arc Hydro tools were used to derive several data sets that collectively describe the

drainage patterns of a catchment. Global Mapper 13 was used in study of Digital Elevation

Model (DEM); ground levels and proposed dam’s cross section were prepared. STEREO NET®

was used for the graphical representation of the collected structural data in order to ease and

facilitate the interpretation of the structural pattern. CorelDraw® 14 was used in production &

layout of the geological map and in figures and diagrams drawing.

Soil texture test has been carried out including, both sieve and hydrometer analysis.

1.6 previous works The early previous work in Nuba Mountains dealt with mineral resources prospecting and

groundwater exploration with some regional geological surveys (e.g. Edmons, 1942; Andrew &

Karkanis, 1945; Mansour & Samuel, 1957; Gebert et al., 1960; Rodis & Iskandar, 1963).

Vail (1973) gave a valuable accounts contain both a geological sketch map of the Nuba

Mountains and a description of the major stratigraphic units.

9

El Ageed (1974) was the first to carry out accurate geological investigations in the Nuba

Mountains and paid particular attention to the iron ore mineralization.

El Ageed & El Rabaa (1981) published an account of the geology and structural evolution of NE

Nuba Mountains.

Vail (1983) independently, reported the presence of Ophiolite in the Nuba Mountains.

Harris et al. (1984) published the first absolute age determination on rocks from the area.

Brinkmann (1986) Brinkmann, K., 1986 Geology and mineralization in the northeastern Nuba

Mountains, Southern Kurdufan, BGR Report (Unpubl.).

Abdelsalam (1987); Abdelsalam & Dawoud (1991) introduced important new aspects into the

discussions of the Nuba Mountains geology.

Abdalla (1999) has studied the Groundwater Hydrology of the west-central Sudan:

Hydrochemical and isotopic Investigations, Flow Simulation and Resources Management.

Khalil (2003) published an account about the natural hazard of the uranium mineralization in the

Nuba Mountains.

Dahab (2006) gave an Assessment and evaluation of groundwater resources in Abu Habil

watershed.

Ibn Ouf (2007) discussed The Geotectonic Setting of Jebel El Dumbier Area and Vicinity.

Abdelgalil, (2008) Studied the Geology and Mineralization Related To An orogenic Igneous

Complexes of Northern Nuba Mountains and Northern Kurdufan.

Mohammed and Yaramanci (2008): published a paper on integrated geophysical groundwater

prospecting techniques on complex aquifer structures in western Sudan.

Ahmed (2010) has assessed water resources in South Kurdufan State with special emphasis on

the socio –economic impact of water projects on rural communities.

10

CHAPTER TWO

GEOLOGICAL AND TECTONIC SETTING OF STUDY AREA

11

CHAPTER TWO

GEOLOGICAL AND TECTONIC SETTING OF STUDY AREA

2.1 Introduction

The Nuba Mountains represent one of the main units of the basement blocks in Sudan. The

basement rocks include both metamorphic and plutonic igneous rocks which are entirely

surrounded by Mesozoic and Cenozoic sedimentary formations filling the rift basins.

Considerable accounts about the geology of the Nuba Mountains were given by several

geologists (Vail, 1973; El Ageed, 1973; El Ageed and El Rabaa, 1980; Shaddad et al., 1973,

Brinkmann, 1986; Abdelsalam, 1987; Abdelsalam and Dawoud, 1991). Vail (1973) firstly

divided the basement rocks of the northeastern Nuba Mountains into four subdivisions: (1)

Metamorphosed schists and gneisses (2) Gabbros which appear to be slightly foliated (3)

Granitic and granodioritic intrusions masses (4) Dykes. Shaddad et al. (1973) classified the

basement complex into two groups: (1) the older gneissose series which make the core of the

Nubian uplift area. (2) The younger series as broad bands in parts of the eastern sector of the

area, most of these rocks are low-grade metamorphosed sediments. Both the two groups are

intruded by igneous intrusions of various ages. Brinkmann (1984) published the first printed

geological map of northeastern Nuba Mountains wherein the basement complex rocks were

subdivided as follows: (1) the oldest rocks are volcano-sedimentary sequence starts with basic to

intermediate metavolcanic rocks with intercalated intermediate to acidic volcanoclasts and

ferruginous chert as well as marble. The metavolcanics are overlain by various metasedimentary

rocks. The high-grade gneisses which are intruded by granitic intrusions of various ages in his

opinion also belong to this sequence. (2) The upper group is structurally overlain by a series of

Ophiolite rocks. (3) The latest group is non ophiolitic igneous intrusions. Abdelsalam (1987) and

Abdelsalam and Dawoud (1991) published considerable accounts about the geological and

structural evolution of northeastern Nuba Mountains. They concluded that, the Precambrian

high-grade gneisses of the continental terrain and the late Proterozoic (Pan-African) low-grade

volcanogenic oceanic assemblage of the northeastern Nuba Mountains are separated by the

Kabus ophiolitic mélange. Based on that work the basement complex was divided into three

groups: the high-grade gneisses, the Ophiolite assemblage, and the low-grade metavolcano-

sedimentary sequence. Vail (1983) reported many bands of late- to post-orogenic gabbros and

granites spanning an interval from 680 to 450 Ma Parallel to the suture zone.

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2.2 Stratigraphical succession

According to the previous studies the following litho-Stratigraphic succession of the study area

(NE Nuba Mountains) will be discussed:

5- Superficial deposits

4- Igneous intrusions.

3- Low-grade volcano-sedimentary sequence.

2- Kabus Ophiolitic mélange.

1- High-grade gneisses.

2.2.1 High-Grade Gneisses:

The terrane of the high-grade gneiss dominated by granitic and granodioritic gneisses associated

with small concordant lenses of amphibolites. It is thought to be constituted most of the

basement complex in northeast Nuba Mountains. Cataclastic deformation and shearing with

mylonite development has been noticed in many of the gneisses outcrops especially at the

contact with the younger series. Generally the gneisses are well foliated in N-S and NNE-SSW

directions.

The gneisses are comprised of quartz, orthoclase and minor albite-oligoclase or microcline,

perthite with variable amount of muscovite, hornblende, green biotite and accessory sphene,

apatite or opaque minerals.

Porphyroblastic augen gneiss is present and in many rocks flaser texture has been developed and

mineral grains are strained, cracked and re cemented with quartz, epidote, sericite and even

calcite. Hornblende is not common in the rocks and is usually altered to biotite and chlorite when

present (Vail, 1973).

Abdelsalam (1987) suggests that, the gneisses of the Nuba Mountains are derived from

sediments, which are intruded by granitic to granodioritic bodies. The assemblage was then

subjected to an upper amphibolite facies grade of metamorphism. This metamorphic event pre

dates a major green schist grade of metamorphism.

The gneissesic terrane is intruded by syn-tectonic anatectic granites which show gradational

contacts and relict foliation that is largely concordant with NE-trending regional gneissic

layering also post-tectonic intrusions are intruded within the gneisses.

13

14

2.2.2 Kabus Ophiolite Zone:

The Ophiolites in the northeastern Nuba Mountains are exposed within 10 km NE-trending belt

extending from Balula area in the north to 20 km south of Kabus separating the high grade gneiss

to the west from the low grade metavolcanosedimentary sequence to the east and identified as

Kabus ophiolitic mélange (Abdelsalam, 1987).

Isolated basic-ultra basic bodies were recognized east of this belt at j. Fazari (2 km southeast of

Uro) and j. Nugara. At j. Nugara one pebble of glaucophane schist was recognized; this

suggested that the ultra-basic and basic rocks may be subduction related (Hirdes & Brinkmann,

1985).

According to Abdelsalam (1987), the Ophiolites rocks within the mélange occur as isolated

boulders of variable shape and different size ranging from mapable unit to microscopic ones. The

blocks at Kabus composed of antigorite serpentinite, talc schist, (interpreted as dunite and

harzburgite), (Hirdes & Brinkmann, 1985) pyroxenites, metagabbro and amphibolites. The

Ophiolite rocks at j. Fazari consist of metagabbro and serpentinite dunite; the metagabbro

composed of tremolite, calcic plagioclase, clinopyroxene and minor amount of epidote, zoisite

and sphene (plate 2.1); the serpentinite dunite composed mainly of serpentinized olivine and

pyroxene in fewer amounts. The zone is characterized by imbricate thrusts with gentle dip

(Abdelsalam & Dawoud, 1991).

Plate 2.1: Photomicrograph of Metagabbro (Pyx =Pyroxene, Srp =Serpentine –XPL)

15

The intensive deformation and metamorphism obscured most of the structural and Petrographic

features of the Ophiolite sequence.

The emplacement of the Ophiolite was followed by deformation phase characterized by tight

folds and associated faulting, the subsequent folding accompanied by green schist facies of

metamorphism. This applied a retrogressive metamorphism to the pre-dated amphibolites facies

affected the dismembered Ophiolite sequence.

2.2.3 Low-Grade Volcanosedimentary Sequence:

Brinkmann (1984) suggested that, the stratigraphic succession started with basic to intermediate

metavolcanic rocks intercalated with intermediate to acid volcanic and ferruginous cherts as well

as marbles.

The existence of intercalated ferruginous metacherts and carbonate rock indicates a submarine

origin to the lava although the pillow lava has never been observed.

The rock is composed of chlorite, epidote, zoisite, actinolite and quartz. Pyrite was frequently

noticed (plate 2.2). The geochemical data obtained by Hirdes (1983), Hirdes & Brinkmann

(1985) and Steiner (1985) as well as petrographic and field evidence suggested two types of

chlorite schist; one is elated to the ophiolitic complex and interpreted by Steiner (1985) as the

basaltic pillow-lava member of the Ophiolite; i.e. to be younger than the serpentenite and gabbro

and the second is not related to the Ophiolite sequence but was formed in an island-arc

environments. Bands of quartz-mica schist’s interpreted to be originated either from acid to

intermediate volcanogenic sediments or from immature sediments (Brinkmann, 1982) were

recognized in j. Er Rugutt and in the area of northeastern extension of j. Tirmi near Al Biteira.

Ridges and low hilly outcrops of quartzite are encountered within the volcano-sedimentary

sequence and they represent always the highest topography because they are resistant to the

weathering. The rock is generally composed of quartz and minor amount of muscovite are

evident (Plate 2.3). The existence of the quartzite is considered as the main reason for demarking

of the folds of Al Biteira and Er Rugutt. It also occurs in j. Uro and in j. Termi syn-form. The

quartzite is widely being folded despite of its brittleness and this may suggest that the folding has

taken place in deep level. Hills, low outcrops and exposures of the graphite schist are widely

encountered in the areas east of Abbasiya, west of Rashad, Uro and Al Biteira. The rocks are

16

foliated in various degrees. Open folds with NE axial plane and plunging 40º in the same

directions have been recognized. Faulting and shearing affected the graphite schist as the rest of

the basement.

Plate2.2: Photomicrograph of strain shadow in pyritefireous chlorite schist (pyt =Pyrite –XPL)

Pate 2.3: Photomicrograph of quartzite –Qtz1 = deformed quartz, Qtz2 second generation quartz (XPL)

17

The graphite schist is composed mainly of quartz, sericite and tourmaline as frequent accessories

(Plate 2.4).

The position of the graphitic schist is still controversial; Brinkmann (1984) suggested that it can

act as substitute for the quartz-mica schist; Hirdes (1983) assumed that it is probably overlain by

quartz-mica schist and Steiner (1985) regards the graphite schist to be the youngest member of

the pre-Cambrian sequence.

Both Steiner (1985) and Hirdes (1983) reported the existence of ferruginous metacherts as thin

band varying in thickness between centimeters and decameters.

The largest band of the marble crops out over a distance of 32 km southwards of Abu Gebeiha

and extends northwards to Abbasiya where isolated outcrops of marbles are suggested to be of

the same band (Vail, 1973). The rocks are fine to medium in texture composed mainly of calcite

and dolomite but silicified varieties are encountered in the fault zones (pate 2.5).

Plate 2.4: Photomicrograph of veinlets of quartz in graphitic schist, Qtz =Quartz, Gr = Graphite (A: under

polarized light, B: under cross Nicole)

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Plate 2.5: photomicrograph of elongated calcite crystals in marble, Cc =Calcite (XPL)

2.2.4 Syn-tectonic Igneous Intrusions:

The syn orogenic igneous rocks are intruded into the high-grade gneisses as well as the

Ophiolites rocks and the low-grade metavolcano-sedimentary sequence (Vail, 1983). The

emplacement of the syn orogenic batholiths was suggested to be around 1000 ma Brinkmann

(1986).

Harris et al (1984) obtained (Sm/Nd) age of 1000 ma and 950 ma for foliated granite and

granodiorite from Rashad and Abbasiya respectively. The Sm/Nd of muscovite granite from El

Obied was estimated to be around 2000ma (Harris, 1984). This estimated age is based on the

assumption that melting occurred during the pan- African from a single source with Sm/Nd ratio

similar to that of average crust. Harris et al. (1984) interpreted the isotopic characteristic of these

granites to indicate either a source of this age or mixed source including presumably, both

Archean and pan African material.

The rocks are mainly composed of K-feldspar (orthoclase and Microcline), plagioclase (Mainly

albite), biotite, hornblende and iron oxide, and epidote and sphene as accessories.

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2.2.5 Superficial deposits

2.2.5.1 Alluvial Deposit:

The Nuba Mountains have been affected by the desert and eolean deposits only on the north part

of the region due to the arid climate and in the southern part where considerable rainfall and the

dense vegetation cover prevent the encroachment of the desert sand (Vail 1972b). The Wadi

Alluvial includes: clays, silt, fine- to medium-grained sands of the lower parts of the Wadis, and

coarse-grained sands to fine gravels of the upper parts of the Wadis. Alluvium deposits are

confined to the Wadis and Khors where they provide an agricultural land and shallow ground

water aquifers.

2.2.5.2 Soil cover

The large clay plains of residual black cotton soils cover wide area at the Nuba Mountains which

will be discussed in detail in separate chapter of investigation.

2.3 Structures

2.3.1 Introduction:

Several structural works have been carried out to explain the complicated structural evolution

and the tectonic setting of NE Nuba Mountains (El Ageed & El Rabaa, 1981; Brinkmann, 1982;

Abdelsalam, 1987; Abdelsalam & Dawoud, 1991). All those authors concluded that the

structures evolved through a poly phased ductile deformational regime, which has been

terminated by a brittle phase.

Detailed mapping for the major structures with scale 1:50,000. Documentation of the style and

situation of minor structures, and measurements on the many structural elements, all these

techniques were applied in order to understand the structural and tectonic setting of the region

and to determine the different phases of deformation.

2.3.2 Primary structures:

The intensive and poly phased of deformation and metamorphism obliterated most of the

primary structures hence, there are no any primary structural features could be observed in the

mapped area.

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2.3.3 Major structures:

2.3.3.1 Al Biteira Antiform:

Al Biteira fold represents the most obvious feature in the Landsat image of the area. It occupies

an area of approximately 100 Km2, and its axis extends for more than 15 Km in a NNE trend. It

is an overturned antiform due to the main deformational phase D2.

The major easterly overturned antiform of Al Biteira is outlined by the quartzite ridges which

define its major physiographic feature in the Landsat image. The graphitic schist represents the

outermost rock type in the fold where as the quartz-muscovite schist has been suggested to

occupy the core of this structure.

The quartzite of Jebel Abu Sunoon defines the closure of this fold. On the western limb the strike

values are about 30° and the dip values range between 70°–75° and these values change in the

strike and 80° to 90° for the dip. The regional plunge value of this fold is about 60°.

Al Biteira Antiform of D2 deformational phase has been affected by the third deformational

phase which is represented by E-W trending faults and shear zones.

2.3.3.2 Er Rugut interference pattern:

The quartzofeldspathic schist, the quartz-muscovite schist, and chlorite schist defines an

interference structure at Jebel Er Rugutt. This structure formed as result of the interference of

two folds of two different deformational phases. The fold of the first phase of deformation D1 is

isoclinal overturned fold with a rounded closure in the SW part of Jebel Er Rugutt. The axial

trace of this fold extends for more than 10 Km in the NNE direction.

The second phase of deformation D2 fold is an overturned concentric antiform produced by the

refolding of the D1 isoclinal fold. The two limbs of this fold dipping to the west, and the eastern

limb being steeper. Observable, that this fold follows the geometry of Al Biteira Antiform,

whereas both of them can be due to the same deformational phase (D2).

2.3.3.3 Faults and shear zones:

In the study area all the major faults more or less belong to D3 Brittle deformational phase.

These faults are strike slip faults with vertical or steeply dipping fault planes, having an E-W

trend direction. These entire faults are related to Al Biteira Antiform. They are perpendicular to

21

the fold axis. Brecciation, mineralization, ferruginization, and mylonitization are common fault

criteria in the area.

Shear zones are also widely scattered in the area having the same trend of faults. D2 fold of Er

Rugutt interference pattern is associated with a radial system of normal faults. These faults

belong to the main ductile phase of deformation D2, where as they reflect a partial brittle

behavior of the lithological units of the structure.

2.3.3.4 Lineaments

The intersection of two foliations S1 and S2 at right angle produces a lineation of D2. This

lineation can be observed in the closure of D2 fold. Most of lineaments trending more or less

north to west direction (fig. 2.4) and related to σ2 of strain ellipsoid (fig 2.3). These types of

fractures are close fractures, therefore can not act as water bearing.

2.4 Structural analysis:

The aim of structural analysis is to analyze number of structural data which were collected

during the detailed study period. These data were in form of measurements taken from different

structural elements (foliation, lineation, fold axes... etc). Through these data a structural model

was constructed to explain different phases of deformation.

STEREO NET® software package was used in the graphical representation of structural data

obtained from Al Biteira and Er Rugutt area. The output was:

Contour diagram of dip & strike of foliation (Fig. 2.2 -A).

Rose diagram for strike of foliation (Fig. 2.2 -B).

Rose diagram for dip direction of foliation (Fig. 2.2 -C).

Resulted diagrams showed that the general trend of foliation is in NNE direction (30°

approximately) and the general dip direction on both two limbs is about 300° (WNW).

Al Biteira Antiform which is outlined by quartzite ridges has an axis extends in NNE direction (a

bout 30°). This fold axis plunges 70° in the same direction. The dip values of the limbs range

between 70° and 75° westward.

By using the strain ellipsoid; the fold axis parallels the greatest strains axis (σ1) has a 30°;

therefore the smallest strain axis (σ2) has a 300° direction (D2 forces direction). When the

22

folding forces increased, the middle stress axis will act in a direction of 75° - 90° (σ3) producing

a refolding, so any fold with an axis in a 75° – 90° direction can be attributed to D2 forces.

Extensional fractures parallel to D2 forces direction (300° or 120°) may be formed. In the last

stage of deformation, release fractures perpendicular to the folding forces direction could be

resulted (Fig. 2.3).

Fig. 2.2: Stereographic projection of Study area; (A): Contour diagram of dip & strike of foliation, (B):

Rose diagram for strike of foliation, (C): Rose diagram for dip direction of foliation.

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Fig. 2.3: stress and strain ellipsoids of Study area. A: Stress, B: strain

Fig. 2.4: Lineaments of study area

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CHAPTER THREE

APPLICATION OF GEOGRAPHICAL INFORMATION SYSTEM (GIS) IN WATERSHED DELINEATION

25

CHAPTER THREE APPLICATION OF GEOGRAPHICAL INFORMATION SYSTEM (GIS) IN

WATERSHED DELINEATION 3.1 Overview of GIS Application

A Geographic Information System (GIS) is computer software used for capturing, storing,

querying, analyzing, and displaying geographically referenced data (Goodchild, 2000).

Geographically referenced data are data that describe both the locations and characteristics of

spatial features such as roads, land parcels, and vegetation stands on the Earth's surface. The

ability of a GIS to handle and process geographically referenced data distinguishes GIS from

other information systems which are the other information system. It also establishes GIS as a

technology important to a wide variety of applications. Clearly, the increased availability of

large, geographically referenced data sets and improved capabilities for visualization, rapid

retrieval, and manipulation inside and outside of GIS will demand new methods of exploratory

spatial data analysis that are specifically tailored to this data-rich environment (Wilkinson, 1996;

Gahegan, 1999). Using GIS databases, more up- to-date information can be obtained or

information that was unavailable before can be estimated and complex analyses can be

performed. This information can result in a better understanding of a place, can help to make the

best choices, or prepare for future events and conditions. The most common geographic analyses

that can be done with a GIS are narrated separately in the subsequent sub-sections.

3.1.1 Mapping The main application in GIS is mapping where things are and editing tasks as well as for

Mapbase query and analysis (Campbell, 1984). A map is the most common view for users to

work with geographic information. It's the primary application in any GIS to work with

geographic information. The map represents geographic information as a collection of layers and

other elements in a map view. Common map elements include the data frame containing map

layers for a given extent plus a scale bar, north arrow, title, descriptive text, and a symbol legend.

3.1.2 Weighted overlay analysis Weighted overlay is a technique for applying a common measurement scale of values to diverse

and dissimilar inputs to create an integrated analysis. Geographic problems often require the

analysis of many different factors using GIS. For instance, finding optimal site for irrigation

requires weighting of factors such as land cover, slope, soil and distance from water supply

26

(Yang Yi, 2003). To prioritize the influence of these factor values, weighted overlay analysis

uses evaluation scale from 1 to 9 by 1. For example, a value of 1 represents the least suitable

factor in evaluation while, a value of 9 represents the most suitable factor in evaluation.

Weighted overlay only accepts integer rasters as input, such as a raster of land cover/use, soil

types, slope, and Euclidean distance output to find suitable land for irrigation (Janssen and

Rietveld, 1990). Euclidean distance is the straight-line from the center of the source cell to the

center of each of the surrounding cells.

3.1.3 Watershed delineation A watershed can be defined as the catchment area or a drainage basin that drains into a common

outlet. Simply, watershed of a particular outlet is defined as an area, which collects the rainwater

and drains through gullies, to a single outlet. Delineation of a watershed means determining the

boundary of the watershed i.e. ridgeline. GIS uses DEMs data as input to delineate watersheds

with integration of Arc SWAT or by hydrology tool in Arc GIS spatial analysis (Winchell et al.,

2008).

3.2 Objective This study will perform drainage analysis on a terrain model. The Arc Hydro tools are used to

derive several data sets that collectively describe the drainage patterns of a catchment. Raster

analysis is performed to generate data on flow direction, flow accumulation, stream definition,

stream segmentation, and watershed delineation. These data are then used to develop a vector

representation of catchments and drainage lines. Using this information, a geometric network

was constructed. Utility of Arc Hydro tools is demonstrated by applying them to develop

attributes that can be useful in hydrologic modeling.

3.3 Terrain Preprocessing Terrain Preprocessing uses DEM to identify the surface drainage pattern. Once preprocessed,

the DEM and its derivatives can be used for efficient watershed delineation and stream network

generation. All the steps in the Terrain Preprocessing menu were performed in sequential order,

from top to bottom as followed. All of the preprocessing steps had been completed before

Watershed Processing functions could be used.

27

3.3.1 Digital Elevation Model (DEM)

Digital Elevation model (DEM) is a grid in which each cell is assigned the average elevation on

the area represented by the cell (Fig. 3.1). This function modifies a DEM by imposing linear

features onto it (burning/fencing).

Fig. 3.1: Digital Elevation Model (DEM) of study area

3.3.2 Fill Sinks

A sink (or depression) is a cell or a group of cells which is at lower elevation than all

neighboring cells (Singh, 2005). If a cell or a group of cells is surrounded by cells with higher

elevation, the water is trapped in that cell and cannot flow. The Fill Sinks function modifies the

28

elevation value to eliminate these problems. This function allows realizing the final DEM within

mistakes due to elevation (Fig. 3.2).

Fig. 3.2: Filled sink of study area Fig. 3.3: Flow direction of study area

3.3.3 Flow Direction

After all sinks are filled (Removed) flow direction are determined for DEM, resulting in a grid,

containing the Flow direction of each cell (Singh, 2005). This function computes the flow

direction for a given grid. The values in the cells of the flow direction grid indicate the direction

of the steepest descent from that cell (Fig. 3.3).

3.3.4 Flow Accumulation

This function computes the flow accumulation grid that contains the accumulated number of

cells upstream of a cell, for each cell in the input grid. To obtain this grid (Fig. 3.4) it is

necessary to use flow direction as input grid.

3.3.5 Stream Definition

This function computes a stream grid contains a value of "1" for all the cells in the input flow

accumulation grid that have a value greater than the given threshold (Brunet, 2010). The

29

resulting stream grid contains a value of "1" for all the cells in the input grid (Fig. 3.5) that have

a value greater than the given threshold. All other cells in the Stream Grid contain no data.

Fig. 3.4: Flow Accumulation of study area Fig. 3.5: Stream Definition of study area

3.3.6 Stream Segmentation

From the stream Definition grid, the stream function creates a grid of stream segments that have

a unique identification (Fig. 3.6). Either a segment may be a head segment, or it may be defined

as a segment between two segment junctions. All the cells in a particular segment have the same

grid code that is specific to that segment.

3.3.7 Catchment Grid Delineation

The catchment Grid delineation function creates a grid in which each cell carries a value (grid

code) indicating to which catchment the cell belongs. The value corresponds to the value carried

by the stream segment that drains the area, defined in the stream segment link grid (Fig. 3.7).

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3.3.8 Catchment Polygon Processing

The catchment polygon processing function takes as input a catchment grid Delineation and

converts it into a catchment polygon feature class (Fig. 3.8). The adjacent cells in the grid that

have the same grid code are combined into a single area (Brunet, 2010).

Fig. 3.6: stream Segmentation

Fig. 3.7: Catchment Grid Delineation Fig. 3.8: Catchment Polygon Processing

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3.3.9 Drainage Line Processing

The drainage line processing function converts the input Stream Link grid into a Drainage Line

feature class. Each line in the feature class carries the identifier of the catchment in which it

resides (Fig. 3.9).

3.3.10 Adjoint Catchment Processing

This function generates the aggregated upstream catchments from the "Catchment" feature class

(Fig. 3.10). For each catchment that is not a head catchment, a polygon representing the whole

upstream area draining to its inlet point is constructed and stored in a feature class that has an

"Adjoint Catchment" tag. This feature class is used to speed up the point delineation process

(Brunet, 2010).

3.3.11 Drainage Point Processing

The drainage point processing function allows generating the drainage points associated to the

catchments. From the drainage line processing output and with this tool, a point is created for all

tributaries (Fig. 3.11).

3.3.12 Watershed processing

A watershed is normally described as the total area of water flowing to a given point or more

often known as pour point (Fig. 3.13). The boundary between two adjacent watersheds is the

drainage line (Singh, 2005). Pour point at which the water flows out of the area. This is the

lowest point in elevation along the boundary or the drainage lines. Delineation of watersheds

depends on the catchment drainage pattern of the watersheds. This in turn depends on the relief

of the area considered.

32

Fig. 3.9: Catchment Polygon with Drainage Fig. 3.10: Adjoint Catchment Processing with drainage

Fig. 3.11: drainage point processing Fig. 3.12: Shows stream order

33

Fig. 3.13: Watershed and Drainage Lines

34

CHAPTER FOUR

WATER HARVESTING TECHNIQUES

35

CHAPTER FOUR WATER HARVESTING TECHNIQUES

4.1 Introduction

People have always gathered water during wet seasons so as to have enough for themselves, their

animals and their crops in dry spells. The earliest known dams were in China in the sixth century

BC. The ruins of ancient dams also exist in the Tigris and the Nile River Valleys. Some Roman

dams built in Italy, Spain and North Africa are still being used today (Lewis, 2002).

Today, dams are built to allow storage of water to give a controlled supply for domestic or

industrial consumption, for irrigation, to generate hydro-electric power, or to prevent flooding.

Large dams are built of earth, rock, concrete or a combination of these materials (for example,

earth and rock fill). They are built as: gravity dams, where the stability is due entirely to the great

weight of material; arch dams, where abutments at either side support the structure; or, arch

gravity dams, which are a combination of the two.

It is well known that Sudan is a dry country characterized by variable rainfall. It is less well

known that, in response to widespread harvesting of water on the small and large scale, Sudan

has not the high water storage per capita. Small dam development has occurred in response to

agricultural expansion, and to the need for a reliable source of water for stock, domestic and

irrigation use, particularly during periods of drought. However, there is a growing belief in the

community that small dams are impacting on water resources in many major catchments by

reducing stream flow and flow duration. Potential and actual impacts of such reductions on the

conflicting needs of the environment, agriculture and industry are cause for concern. These

concerns are set against a background of changes including increased areas of intensive land uses

such as viticulture and horticulture, and the development of farmland into rural residential

subdivisions in commuter belts surrounding major cities and rural centers. These changes are

associated with increased small dam development. In a significant proportion of cases,

particularly where intensive land use changes have occurred, small dams are constructed that

exceed the available water resource. Where this occurs, downstream impacts on stream flow will

be the cause of conflict between users (including the environment).

36

4.2 Current situation of water availability 4.2.1 surface water

Rainfall is usually evenly distributed all over the area, starting from May to November and it is

highly variable from one rainy month to another, Sometimes two-week dry spells in July and

August take place. The variability of monthly rainfall during a single rainy season ranges from

37% to 70%. According to these deviations, the range of annual rainfall is hence 465-991mm in

Kadugli, 456-1004mm in Rashad.

These amounts of rainfall during autumn (rainy season) generate water pools which accumulate

in depressions and were being used by people for their house stocks and animals. These pools no

longer being used and they dry out after the end of rainy season. Hafirs (Artificial depressions)

are used to store water during autumn and the water remaining till the end of February.

4.2.2 Groundwater

Study area is underlying by crystalline rocks and covered by clay soil. This fact caused limitation

of groundwater availability. In some major streams, shallow alluvial aquifer existed and being

recharged annually by flood water.

Many hand –dug wells and hand –pump wells were drilled in alluvial aquifer of the major

streams and fractures. The amount of water in these aquifers decreased gradually day by day

after the end of rainy season till to be very difficult to get water at the end of June.

4.3 Planning

Despite all its broad water resources and according to the concept of “Resources Governance”

which depends only on the actual distribution of available water resources, Sudan is universally

classified among the countries listed as under the water poverty line: less than 1000 m3/head/per

year.

4.3.1 Assessing water needs

Water is the most plentiful and vital liquid on earth. No life, as we know it, could exist without

water as it provides the essential medium in which all things grow and multiply. In recent years

the steady growth in the numbers of agricultural businesses, including viticulture, aquaculture,

irrigating crops and grazing animals, has increased the demand for water supplies.

37

Rainwater is the main source of high quality water for human Consumption, providing that

guttering and tanks are kept in good order. In some cases bore water is used, but it may require

treatment to remove or neutralize the minerals it contains. Where the terrain permits, rainfall and

run-off gravitating to various categories of dams (for example, off-stream and in stream dams)

provide the people water supplies.

4.3.2 Planning of water supplies

When decided the most appropriate source of water for Small dam, the following steps was

taken:

i. The purpose for which the water is to be used was determined as for a combination of

household and stock.

ii. The quantity of water required for the different purposes, time of year and seasonal

use and conditions were determined as for winter and summer.

iii. The source of water supply was determined as unregulated.

According to Lewis (1993), these factors are a guide to planning and they differ with almost

every property. The most likely base can be established by calculating the average daily or

average annual requirements for each proposed use of the dam. It is only after these facts are

established that harvesting, storing and distributing the water resource can be planned.

4.3.3 Assessment of catchment yield

The initial question to be asked when considering the development of any storage dam on a

property is how much water can be harvested in a catchment from overland run-off.

4.3.3.1 Factors controlling catchment yield

Catchment yield is the volume of water that flows from a catchment past a given point (such as a

stream gauging station) and is generally calculated on an annual basis (Beavis and Lewis, 1999).

It comprises surface run-off and base flow (discharge from shallow and deep groundwater).

Catchment yield will vary according to a number of hydrological and physical factors, which

control how much water is delivered to, retained by and transported from a catchment.

38

i. Hydrological factors

Run-off may be regarded as the residue of rainfall after losses due to interception by vegetation,

surface storage, infiltration, surface detention and waterway detention. There is always a time lag

between the beginning of rainfall and the generation of run-off. During this time lag, rainfall is

intercepted by vegetation, infiltrates the soil, and surface depressions start to be filled. Run-off

occurs when the infiltration capacity is exceeded, or the precipitation rate exceeds the rate of

infiltration. Thus the depth of water builds up on the surface until the head is sufficient to result

in run-off. As the flow moves into defined waterways, there is a similar build-up in the head with

volume of water, and this is termed waterway detention. The water in surface storage is

eventually diverted into infiltration or evaporation pathways (Beavis and Howden, 1996; Beavis

and Lewis, 1999).

Rainfall duration, intensity, and distribution influence both the rate and volume of run-off.

Infiltration capacity normally decreases with time, so that a short storm may not produce run-off,

in contrast to a storm of the same intensity but of long duration. However, an intense storm

exceeds the infiltration capacity by a greater margin than a gentle rain. Therefore, the total

volume of run-off is greater for an intense storm even though total precipitation is the same for

the two events. In addition, an intense storm may actually decrease the infiltration rate by its

destructive action on the structure of the soil surface. Generally, the maximum rate and volume

of run-off occur when the entire catchment contributes. However, an intense storm on one

portion of the catchment may result in a greater run-off than a moderate storm over the entire

catchment.

ii. Physical factors

Physical factors affecting run-off include topography, soil type and antecedent soil moisture

conditions, catchment size, shape and orientation, and management practice. Topographic

features such as slope and the extent and number of depressed areas influence the volume and

rate of run-off. Catchments having extensive flat or depressed areas without surface outlets have

lower run-off than areas with steep, well-defined drainage patterns. A catchment with a northerly

aspect will dry out faster than one with a southerly aspect. Soil texture, fabric, clay mineralogy

and antecedent moisture conditions have major impacts on the infiltration rate and capacity, and

thus influence run-off. Sandy soils with an open fabric have high infiltration rates and generate

39

fewer run-offs than clayey soils with a closed fabric (where intergranular spaces are smaller and

there is less connectivity between pores). Both run-off volumes and rates increase with

catchment area. However, run-off rate and volume per unit area decrease as the area increases.

Vegetation cover and management practices influence infiltration rate by intercepting

precipitation and modifying soil structure respectively.

Vegetation also retards overland flow and increases surface detention to reduce peak run-off

rates. Structural works such as dams, weirs, pipe culverts and levees all influence run-off rates by

either directing surface water into preferential flow lines or storing water.

4.3.3.2 Methods of estimating catchment yield

In study area, where there is no a reliable flow in streams or Khors, storage must be constructed

to meet all the water requirements for the storage period as well as evaporation and seepage

losses. The storage period is that interval during which there is no run-off into the dam. Table

(4.1) gives a ‘rule-of-thumb’ estimate of the storage period required in areas with different

average rainfall. However, the average annual rainfall in study area is 800 mm, according to this

table storage period must be 12 months to meet the water need.

Table (4.1) storage period (modified after soil conservation Authority, 1983)

Average annual rainfall (mm) Storage period (months)

> 650 12

450 –650 18

250 – 449 24

< 250 30 - 36

Two methods are currently used in many countries (Australia, USA, and India) for estimating the

yield of a catchment. One is the United States Department of Agriculture (USDA, 1969) method

of estimating daily run-off. This is based on daily rainfall records for the district. The longer the

period of record, the better the results. The other method is based on the assumption that

catchment yield is a percentage of the average annual rainfall.

40

Table 4.2 provides an estimate of yields from small natural catchments. The reliability column

relates to the number of years in a ten-year period in which the given percentage yields will be

equaled or exceeded. For irrigation and stock, a reliability of eight years out of ten is acceptable,

and for domestic schemes the aim is nine years out of ten.

The selection of percentage yield within the given range depends on local experience. For

example, the lower limits in the yield column usually include forests, areas of cultivation and

improved pastures.

Table 4.2: Yield from natural catchments (modified after Burton, 1965 and Nelson, 1983).

Yield as percentage of average rainfall (Y)

Average

Annual

Rainfall

(R) (mm)

Total

Annual

Evaporation

(mm)

Reliability

(years out

of ten)

Shallow

Sand or

loam soil

(%)

Sandy

Clay

(%)

Elastic

Clay

(%)

Clay Pans

or Inelastic

clays

(%)

>1100 < 1000 8 10 – 15 12 – 20 15 –25 15 – 30

900 –1100 < 1000 8 10 – 15 10 – 15 12.5 –20 15 – 25

500 – 899 1000 – 1300 8 8 – 5 7.5 – 12 7.5 – 15 10 – 15

500 – 899 1000 – 1800 8 8 – 5 15 – 12 5 – 12 10 – 15

400 – 499 1000 – 1800 8 3 – 4 3 – 7.5 4 – 6 7.5 – 12.5

250 – 399 < 1800 8 1.5 – 3 1.5 – 5 1 – 3 2 – 5

< 250 > 1800 8 1 – 2 1.5 – 3 1 – 2 2 – 5

Note:

i. For 9 out of 10 years reliability multiply percentage by ퟐퟑ.

ii. Number should be halved if catchment sown to improved perennial pasture.

The run-off, in megalitres, from the catchment is calculated from Table 4.2 and according to the

following formula:

푉 = 퐾 × 퐴 × 푅 × 푌

Where V = run-off yield volume (ML)

41

K = conversion to megalitres = 0.01

A = catchment area (hectares),

R = average annual rainfall (millimeters), and

Y = yield as percentage (using Table 4.2, and expressed as a decimal, for

example, 12.5% = 0.125; 7.5% = 0.075).

4.3.4 Dam site selection

Surveys have indicated that a large proportion of small dams fail because of poor planning,

unsatisfactory sitting, faulty construction or lack of maintenance. Such costly failures can usually

be avoided. The choice of a suitable dam site should begin with preliminary studies of possible

sites. Where more than one site is available, each should be studied separately with a view of

selecting the one that proves most practical and economical (DoA Vic, 1978; SRW, 1995).

From an economic viewpoint, the proposed dam sites were located where the largest storage

volume can be obtained with the least amount of earthworks. This condition will occur,

generally, at a site where the valley is narrow, side slopes are relatively steep, and the slope of

the valley floor will permit a large deep basin. When the sites were located attention paid where

sudden release of water due to failure of the dam would not result in loss of life, injury to persons

or livestock, damage to residences.

4.3.4.1 Choosing a dam site

When choosing a dam site (Lewis, 1995b), the following points need to be considered:

i. Storage yield from the catchment

Yield is the volume of water harvested from the dam catchment area. It depends on rainfall, plant

cover, slope, soil type, area and other factors. Three questions need to be asked when selecting a

dam site:

• What is the catchment area above the dam?

• How much water will the catchment yield?

• Would the catchment yield be substantially reduced if another dam were to be built in

the same catchment?

42

ii. Increased catchment harvest

Often dams cannot fill because the catchment area produces insufficient run-off. The catchment,

or source of water of a dam, should generate enough water each year to fill it. If the catchment is

large enough, graded drains can be constructed to divert run-off from adjacent areas. Hard

surface areas such as roads and roofs can also be used to increase the yield.

iii. Soil assessment and testing

Although clay soils are imperative to prevent leaking dams, it should be noted that all clays do

not hold water. Physical and chemical properties can make some clay soils prone to seepage or

tunnelling, both of which result in bank failure.

To test the suitability of the soil, samples were taken from the borrow pit and along the bank

centre-line. These tests showed whether or not the soil contains clay.

iv. Planning outlet structures

Many dams fail because of an inadequate or incorrectly located spillway or insufficient

freeboard. If a spillway is too small to cope with storm flood-flows, water will flow over the top

of the bank which may then breach. A badly designed or constructed spillway can cause erosion

of the spillway and lead to complete failure of the dam. Therefore, the spillway should be large

enough to handle and dispose of flood-waters safely, without damaging the dam bank or causing

erosion of the spillway.

4.3.5 Dam storage size

In order to determine the required capacity of a dam, it is necessary to allow for environmental

requirements, and losses such as evaporation and seepage. Accurate calculations of the losses

can be complex. However, as an approximation, it is advisable to allow for losses in the order of

40 per cent of total storage volume, depending on locality and weather conditions. This means

that only 60 per cent of water stored is available for consumption, and this is commonly referred

to as the useable volume (Fig. 4.1).

During low rainfall periods, replenishment rates can be too low to replace consumed water.

Therefore, storages need to be large enough to accommodate these periods. Dams should be able

to cope with drought periods at least equal to 18 months, including two summer seasons.

43

Fig. 4.1: Water losses and needs 4.3.5.1 Evaporation losses Evaporation can significantly reduce production. More than 40 per cent of water can be lost by

evaporation from stored water in a 12-month period in certain locations. This loss will reduce the

amount of water available for consumption, with possible significant production losses.

Since evaporation is often the biggest consumer of water from a dam, it must be taken into

account when choosing dam size. Evaporation will vary according to climatic zone, time of year,

dam size, dam shape and the specific location of the dam.

A first approximation of annual loss to evaporation can be calculated from the following

relationship:

LE = 0.67 E × AF

Where LE = evaporation loss (L)

E = local annual evaporation (mm)

AF = surface area of the dam at full supply level (m2)

In study area, Potential evaporation reaches its peak during summer, with monthly values of 220

mm. This is associated with a low relative humidity, during autumn potential evaporation falls to

170 mm per month.

4.3.5.2 Ways of controlling evaporation

Various means of controlling evaporation have been suggested, including chemical films,

floating or suspended material, windbreaks and emergent water plants.

44

However, more information is needed in order to measure the relative efficiency of these

methods.

A recent study by RMIT University, Victoria -Australia, into aspects of evaporation from off-

waterway storage, recommended the following ways of decreasing evaporation:

i. Floating rings with reflective caps significantly reduced evaporative losses, and

further development of this option is proceeding. The rings are formed from strips of

buoyant plastic, covered with a cap of bubble plastic and painted with white reflective

paint.

ii. Initial tests indicated that windbreaks have potential for reducing evaporation, but

further development of this idea is needed.

iii. Two simple methods for reducing losses are to have deeper storages, and to split

large storages into cells.

4.3.5.3 Seepage losses

Pervious sub-surface soils are not always detected in the initial investigation because landowners

cannot afford, or do not understand, the necessity for comprehensive soil testing of the base of a

storage.

The borrow pit is usually located beneath the proposed storage. Material from this source that is

used in the embankment is not necessarily impervious and may result in seepage.

When the borrow pit is within a storage there are underlying strata that may not be watertight.

Excavating these pervious seams will result in seepage and leakage through the base. One

problem that often occurs with high storage ratio dams, in wide flat bottomed valleys, is that they

may contain a considerable depth of sand, gravel or silt.

4.4 Investigation

The suitability of a dam site depends not only on the embankment but also on the ability of the

soils in the storage area to hold water. The soil profile should contain a layer of material that is

sufficiently impervious and thick enough to prevent seepage losses. Excellent materials for this

purpose are clays and silty clays, although sandy clays are usually satisfactory. Coarse textured

sands and sand-gravel mixtures are highly pervious and therefore generally unsuitable. In some

45

areas, such as flood plains, it is often possible to impound a limited depth of water in areas where

no impervious layer exists in the soil profile but where a high water table exists at, or near, the

ground surface. Some limestone areas are especially hazardous for use as dam sites. They may

form tunnels, cracks or channels in the limestone below the ground surface, which are not visible

from the surface. These lines of seepage may drain a dam in a very short period of time. In

addition, soils in these areas are often granular. The granules do not break down readily in water

and the soils remain highly permeable (Lewis, 2001).

4.4.1 Soil testing Without extensive investigations and laboratory tests, it is difficult to recognize all of the factors

that might make a site undesirable. The absence of a layer of relatively impervious material over

a storage area does not necessarily mean that the site must be abandoned. Regarding with this

aspect sites soil samples were taken and analyzed for foundation and embankment material for

some selected sites.

4.4.1.1 Foundation

The foundation includes the stream floor and its side slopes or abutments. The requirements of a

foundation for an earth-fill dam are that it provides support for the overlaying embankment under

all conditions of saturation and loading, and that it provides sufficient resistance to seepage to

minimize loss of water. Poor foundations can lead to failure of a dam due to cracking, tunneling,

sliding, settlement, or uplift.

The soil conditions under an embankment were investigated to ensure that the site is suitable and

that a safe structure can be designed. The complexity of the foundation survey was depended

upon the site conditions and on the height of the proposed dam wall. Test holes was taken at

intervals along the centre-line of each proposed dam site as subjected by WAWA, 1991(Fig. 4.2

and Plate 4.1), using a hand dug to dig holes to determine the nature of the soil profile. The depth

and spacing of the holes was sufficient to determine the suitability of the foundation. The

location of these holes depends on the occurrence of significant changes in the soil profile.

The holes were deep enough (0.5 to 2 m) to identify the underlying materials that may affect the

design or safety of the structure. A record, or log, of each hole or test pit was made with location,

depth and classes of materials encountered.

46

4.4.1.2 Borrow pit for embankment material

Suitable excavated material needs to be found in sufficient quantities for construction of the

embankment. The further the excavation is from the embankment site, the greater the placement

costs. This is a good reason for having the borrow pit inside the storage area. Test holes was

made in the chosen borrow pit areas to establish whether sufficient volumes of suitable material

are available (Plate 4.2).

Selected materials for construction of a dam wall includes gravelly sands which has the strength

for the embankment to remain stable, and clay soil has a sufficiently low permeability (when

compacted) to prevent excessive seepage of water through the dam wall.

Fig. 4.2: Depth of test holes along centre-line (a, b, c, d, and e are depths to stream bed, T H =Test Holes),

(Modified after WAWA, 1991).

4.4.1.3 Spillway site

During a storm event, it becomes necessary to bypass run-off around the embankment of a small

dam through an earth spillway. For safety reasons, the spillway should be located on a natural

surface and not on the fill material. Thus, holes were placed along the centre-line of the proposed

spillway to determine the type of material that will be encountered, its erodability, and its

suitability. The results of each proposed dam sites will be discussed separately in each site.

47

Plate 4.1: Test hole was made in Al Biteira Proposed dam site, showed three soil layers silty clay,

medium to coarse sand and very coarse sand, total depth is 1 m

Plate 4.2: Shows embankment materials Er Rugut proposed Dam site, (A) Gravelly sand, (B) Test bit in

clay soil with depth 80 cm.

4.4.2 Site selection criteria A problem sometimes associated with selected sites is that there may be substantial depths of

pervious materials (for example, 3 m). This could require a deep cut excavation for the core

trench placement beneath the dam. The presence of pervious materials could also result in more

expensive de-watering problems during excavations (Lewis, 2002).

48

In studied area, four dam sites were proposed: (1) Kabus, (2) Al Ufaynah, (3) Er Rugutt and (4)

Kurunn (Table 4.3 and Fig. 4.3) and investigated for topography, soil tests and seepage losses.

These categories will be discussed in detail under separated titles.

Table (4.3): Locations of Proposed Dam sites and Catchment covered area and its run-off Dam site Longitude Latitude Catchment area

(hectare) Run-off

(megalitres) Kabus 31.254 11.764 12000 14400 Al Ufaynah 31.362 11.759 7500 7200 Er Rugutt 31.348 11.647 4500 5400 Kurunn 31.441 11.569 13600 16320

4.4.2.1 Topography The study of four proposed dam sites showed that all of these sites area lies in the north- eastern

edge of a gentle topographical swell in the central plain of the Sudan and it represented in

different topographic terranes varying from hilly to peniplains (fig. 1.2) and it rises to a height of

600m above mean sea level. And the streams are flowing between the hills which make the

selected sites very suitable to be dam sites.

4.4.2.2 Soil test 4.4.2.2.1 Soil texture tests Soil texture tests are carried out to determine soil types. The relative proportions of sand, silt and

clay are used to determine the textural class of a soil. The internationally accepted and most used

tool for initially identifying soils for dam building is the United States Department of Agriculture

(USDA) texture diagram shown in Figure 4.4. Also included, in Table 4.4, is the texture classes

as defined by a percentage for sand and clay were adopted in this study.

35 samples were collected from the four proposed sites; along proposed dam’s axis and reservoir

body to indentify soil types and textures. Mechanical and hydrometer analysis was carried out on

all 35 samples (Table 4.11)

The mechanical or sieve analysis was performed to determine the distribution of the coarser,

larger-sized particles, and the hydrometer method was used to determine the distribution of the

finer particles.

49

Fig. 4.3: Watersheds and proposed Dam sites

I. Equipment:

Balance, Set of sieves, Cleaning brush, Sieve shaker, Mixer (blender), 152H Hydrometer,

Sedimentation cylinder, Control cylinder, Thermometer, Beaker, Timing device (plate 4.3).

II. Test Procedure:

a. Sieve Analysis:

The weight of each sieve as well as the bottom pan was recorded to be used in the analysis, the

weight of the given dry soil sample is recorded. After ensured that all sieves are clean, and

50

assembled then in the ascending order of sieve numbers; soil sample was poured into the top

sieve and the cap placed over it.

Sieve stack has been placed in the mechanical shaker and was shaken for 10 minutes.

The stack has been removed from shaker and carefully the weight of each sieve was recorded

with its retained soil. In addition, the weight of the bottom pan with its retained fine soil has been

recorded.

b. Hydrometer Analysis:

The fine soil from the bottom pan of the sieve set has been taken and placed it into a beaker. 125

mL of the dispersing agent (sodium hexametaphosphate (40 g/L)) solution was added. The

mixture was stirred until the soil is thoroughly wet. The soil soak was let for at least ten minutes.

Table 4.4: Texture classes (After Fietz, 1969; Stephens, 1991).

While the soil is soaking, 125mL of dispersing agent was added into the control cylinder and

filled with distilled water to the mark. The reading at the top of the meniscus formed by the

hydrometer stem and the control solution was taken. A reading less than zero is recorded as a

negative (-) correction and a reading between zero and sixty is recorded as a positive (+)

correction. This reading is called the zero correction. The meniscus correction is the difference

between the top of the meniscus and the level of the solution in the control jar (Usually about

+1). The control cylinder in such a way that the contents are mixed thoroughly was Shake. The

hydrometer and thermometer were inserted into the control cylinder and the zero correction and

temperature noted respectively.

Textural class Sand % Clay %

Sand >85 % –

Loamy Sand 70 – 85 % –

Sandy Loam 50 –70 % < 20 %

Sandy Clay Loam 45 – 80 % 20 –35 %

Clay Loam < 45 % 40 %

Sandy Clay 45 – 65 % >35 %

Clay < 45 % >40 %

51

Fig. 4.4: Textural classification chart (after USDA, 1967).

The soil slurry was transferred into a mixer by adding more distilled water until mixing cup is at

least half full. Then the solution has been mixed for a period of two minutes. Immediately the

soil slurry transferred into the empty sedimentation cylinder. Distilled water was added up to the

mark.

The open end of the cylinder was covered with a stopper and secured it with the palm of hand.

Then the cylinder turned upside down and back upright for a period of one minute.

The cylinder was set down and the time recorded. The stopper was removed from the cylinder.

After an elapsed time of one minute and forty seconds, very slowly and carefully the hydrometer

was inserted for the first reading. (It should take about ten seconds to insert or remove the

hydrometer to minimize any disturbance, and the release of the hydrometer should be made as

close to the reading depth as possible to avoid excessive bobbing).

The reading was taken by observing the top of the meniscus formed by the suspension and the

hydrometer stem. The hydrometer was removed slowly and placed back into the control cylinder.

Very gently spin it in control cylinder to remove any particles that may have adhered.

52

Hydrometer readings were taken after elapsed time of 2 and 5, 8, 15, 30, 60 minutes and 24

hours.

Plate 4.3: soil texture test equipments; A = Set of sieves, B = Balance, C = Sieve shaker and D =

control cylinder, Hydrometer and soaking soil specimen

53

III. Data Analysis:

1. Sieve Analysis:

The mass of soil retained on each sieve was obtained by subtracting the weight of the empty

sieve from the mass of the sieve + retained soil, and this mass recorded as the weight retained on

the data sheet. The sum of these retained masses was approximately equals the initial mass of the

soil sample.

The percent retained on each sieve was calculated by dividing the weight retained on each sieve

by the original sample mass.

The percent passing (or percent finer) was calculated by starting with 100 percent and

subtracting the percent retained on each sieve as a cumulative procedure (table 4.9).

A semilogarithmic plot of grain size vs. percent finer has been made (figure 4.5).

2. Hydrometer Analysis:

Meniscus correction was applied to the actual hydrometer reading. The effective hydrometer

depth L in cm (for meniscus corrected reading) obtained from Table 1. For known Gs of the soil

(2.65), the value of K obtained from Table 2. The equivalent particle diameter was calculated by

using the following formula:

퐷 = 퐾퐿푡

Where t is in minutes, and D is given in mm.

The temperature correction CT was determined from Table 3. Correction factor “a” was

Determined from Table 4 using Gs. corrected hydrometer reading was Calculated as follows:

푅 = 푅 − 푧푒푟표 푐표푟푟푒푐푡푖표푛 + 퐶

Percent finer was calculated as follows:

푃 =푅푐 × 푎푊 × 100

Where WS is the weight of the soil sample in grams.

54

Percent fines were Adjusted as follows (table 4.10 for sample 1 –Beteira proposed dam site:

푃 =푃 × 퐹

100

F200 = % finer of #200 sieve as a percent

The grain size curve D versus the adjusted percent finer was plotted on the semilogarithmic

sheet (fig. 4.5).

4.4.2.2.2 Unified soil classification Materials are classified according to the ‘Unified Soil Classification’ system. This system of

classification uses grouped symbols to indicate the physical properties of the material (Lewis,

2002). The system is based on the size of the particles, the relative amounts and the

characteristics of the very fine particles. Table 4.12 provides the list of grouped symbols used

under the ‘Unified Soil Classification’, with their common names, organized in order from

largest to finest particles, which is gravels, sands, silts, clays and organic material.

To define the textural classification of soils, laboratory techniques had been carried out as

described in section 4.3.2.2.1 and the results are shown in table 4.11. However, with experience

and specific local knowledge, hand testing was used to determine texture can prove important in

the initial stages of identifying appropriate earth fill materials. Clay soil sites were defined in the

field. These soils are used for the core and upstream batter of the embankment. Silts are often

similar in both appearance and feel to wet clays when dry, but can usually be differentiated when

wet as the clay will exhibit sticky, plastic-like characteristics while silt has a silky, smooth

feeling with a tendency to disperse.

Hand-testing techniques involve taking a small sample of a soil, dampening it, and rolling it into

a ball to examine its cohesive constituents. Good clay can be manipulated into a thin strip

without breaking up, rolled into a ball and dropped onto a flat surface from waist height without

cracking unduly, and cut to exhibit a shiny, smooth surface.

55

Table 4.5: Values of Effective Depth Based on Hydrometer and Sedimentation Cylinder of Specific Size (after Ritter and Paquette, 1960).

Hydrometer 151H Hydrometer 152H Actual

Hydrometer

Reading

Effective

Depth, L

(cm)

Actual

Hydrometer

Reading

Effective

Depth, L

(cm)

Actual

Hydrometer

Reading

Effective

Depth, L

(cm)

1.000 16.3 0 16.3 31 11.2 1.001 16.0 1 16.1 32 11.1 1.002 15.8 2 16.0 33 10.9 1.003 15.5 3 15.8 34 10.7 1.004 15.2 4 15.6 35 10.6 1.005 15.0 5 15.5 36 10.4 1.006 14.7 6 15.3 37 10.2 1.007 14.4 7 15.2 38 10.1 1.008 14.2 8 15.0 39 9.9 1.009 13.9 9 14.8 40 9.7 1.010 13.7 10 14.7 41 9.6 1.011 13.4 11 14.5 42 9.4 1.012 13.1 12 14.3 43 9.2 1.013 12.9 13 14.2 44 9.1 1.014 12.6 14 14.0 45 8.9 1.015 12.3 15 13.8 46 8.8 1.016 12.1 16 13.7 47 8.6 1.017 11.8 17 13.5 48 8.4 1.018 11.5 18 13.3 49 8.3 1.019 11.3 19 13.2 50 8.1 1.020 11.0 20 13.0 51 7.9 1.021 10.7 21 12.9 52 7.8 1.022 10.5 22 12.7 53 7.6 1.023 10.2 23 12.5 54 7.4 1.024 10.0 24 12.4 55 7.3 1.025 9.7 25 12.2 56 7.1 1.026 9.4 26 12.0 57 7.0 1.027 9.2 27 11.9 58 6.8 1.028 8.9 28 11.7 59 6.6 1.029 8.6 29 11.5 60 6.5 1.030 8.4 30 11.4 1.031 8.1 1.032 7.8 1.033 7.6 1.034 7.3 1.035 7.0 1.036 6.8 1.037 6.5

56

Table 4.6: Values of k for Use in Equation for Computing Diameter of Particle in Hydrometer Analysis (after Ritter and Paquette, 1960).

Temperature

°C

Specific gravity of soil particles

2.45 2.50 2.55 2.60 2.65 2.70 2.75 2.80 2.85 16 0.01510 0.01505 0.01481 0.01457 0.01435 0.01414 0.01394 0.01374 0.01356 17 0.01511 0.01486 0.01462 0.01439 0.01417 0.01396 0.01376 0.01356 0.01338 18 0.01492 0.01467 0.01443 0.01421 0.01399 0.01378 0.01359 0.01339 0.01321 19 0.01474 0.0149 0.01425 0.01403 0.01382 0.01361 0.01342 0.01323 0.01305 20 0.01456 0.01431 0.01408 0.01386 0.01365 0.01344 0.01325 0.01307 0.01389

21 0.01438 0.01414 0.01391 0.01369 0.01348 0.01328 0.01309 0.01291 0.01273 22 0.01421 0.01397 0.01374 0.01353 0.01332 0.01312 0.01294 0.01276 0.01258 23 0.01404 0.01381 0.01358 0.01337 0.01317 0.01297 0.01279 0.01261 0.01243 24 0.01388 0.01365 0.01342 0.01321 0.01301 0.01282 0.01264 0.01246 0.01229 25 0.01372 0.01349 0.01327 0.01306 0.01286 0.01267 0.01249 0.01242 0.01215 26 0.01357 0.01334 0.01312 0.01291 0.01272 0.01253 0.01235 0.01218 0.01201 27 0.01342 0.01319 0.01297 0.01277 0.01258 0.01239 0.01221 0.01204 0.01188 28 0.01327 0.01304 0.01283 0.01264 0.01244 0.01255 0.01208 0.01191 0.01175 29 0.01312 0.01290 0.01269 0.01269 0.01230 0.01212 0.01195 0.01178 0.01165 30 0.01298 0.01276 0.01256 0.01236 0.01217 0.01199 0.01182 0.01165 0.01149

Table 4.7: Temperature Correction Factors CT Table 4.8: Correction Factors a for Unit Weight of

Unit Weight of Soil Solids,

(g/cm3)

Correction factor

(a)

2.85 0.96

2.80 0.97

2.75 0.98

2.70 0.99

2.65 1.00

2.60 1.01

2.55 1.02

2.50 1.04

Temperature (°C) Factor (CT)

15 1.10 16 – 0.90 17 – 0.70 18 – 0.50 19 – 0.30 20 0.00 21 + 2.00 22 + 4.00 23 + 7.00 24 + 1.00 25 + 1.30 26 + 1.65 27 + 2.00 28 + 2.50 29 + 3.05 30 + 3.80

57

Table 4.9: sieve analysis of sample (1) –Al Ufaynah site Sieve

Number Diameter

(mm) Soil Retained

(g) Percent retained

Cumulative Percent Retained

Percent Passing

4 4 49.9 9.5 9.5 90.5 10 2 36.5 7.0 16.5 83.5 20 1 42.1 8.0 24.5 75.5 40 0.5 40.0 7.6 32.1 67.9 60 0.25 23.0 4.4 36.5 63.5 140 0.125 91.0 17.4 53.9 46.1 200 0.063 10.2 1.9 55.8 44.2 Pan --- 231.0 44.1 100.0 0.00 Total 523.7

Table 4.10: Hydrometer analysis of sample (1) – Al Ufaynah site; hydrometer Number 152H, specific gravity of soil 2.56, zero correction +16, meniscus correction +1.

Date Time Elapsed Time (min)

Temp. (°C)

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm

CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

08/15 4:06pm 0 25 55 56 7.1 0.01326 0 +1.3 1.018 - - - 4:07 1 25 47 48 8.6 0.01326 0.03029 +1.3 1.018 42.3 86.1 37.8 4:08 2 25 42 43 9.2 0.01326 0.02844 +1.3 1.018 37.3 75.9 33.3 4:10 4 25 40 41 9.6 0.01326 0.02054 +1.3 1.018 35.3 71.9 31.6 4:14 8 25 37 38 10.1 0.01326 0.01490 +1.3 1.018 32.3 65.8 28.6 4:22 16 25 32 33 10.9 0.01326 0.01094 +1.3 1.018 27.3 55.6 24.1 4:40 34 25 28 29 11.5 0.01326 0.00771 +1.3 1.018 23.3 47.4 20.8 6:22 136 23 22 23 12.7 0.01356 0.00411 +0.7 1.018 16.7 34 14.9

08/16 5:24pm 1518 22 15 16 13.7 0.01366 0.00130 +0.4 1.018 9.4 19.1 8.4

Fig. 4.5: grain size analysis curve of sample (1) –Al Ufaynah Proposed site

58

Table 4.11: Soil Texture test

Site Name Sample No.

Sand %

Clay %

Textural class Soil Group Soil Name

Kabus

1 40.6 50.2 Clay CL Silty Sandy Clay 2 35.0 60.3 Clay CL Silty Sandy Clay 3 60.5 35.1 Sandy Clay SC Silty Clayey Sand 4 30.4 40.8 Clay Loam CL Silty Sandy Clay 5 10.2 80.6 Clay ML/CH Sandy Clay 6 35.7 40.2 Clay loam CL Silty Sandy Clay 7 42.8 55.4 Sand Clay ML/CH Sandy Clay 8 65.0 30.7 Sandy Clay Loam SC Silty Clayey Sand 9 75.1 17.5 Loamy Sand GM Gravelly Silty Sand

Al Ufaynah

1 46.4 44.1 Sandy Clay SP Gravelly Silty Sand 2 80.0 16.5 Sand Clay loam SM Silty Sand 3 75.3 – Loamy Sand GP Gravelly Sand 4 50.4 35.2 Sand Clay Loam CL Silty Clayey Sand 5 60.0 15.8 Sandy Loam SM Silty Sand 6 75.7 25.3 Sand Clay Loam CL Silty Clayey Sand 7 70.1 10.5 Sandy Loam SP Gravelly Silty Sand 8 65.6 15.8 Sandy Loam SC Clayey Sand

Er Rugutt

1 70.0 – Loamy Sand GP Gravelly Sand 2 39.6 40.8 Clay Loam CL Silty Sandy Clay 3 46.3 20.7 Sandy Clay Loam SC Silty Clayey Sand 4 37.8 52.4 Clay ML/CH Sandy Clay 5 39.5 58.6 Sandy Clay ML/CH Sandy Clay 6 30.2 60.3 Clay CL Silty Sandy Clay 7 45.0 30.8 Sandy Clay Loam SC Silty Clayey Sand

Kurunn

1 25.2 72.4 Clay ML/CH Sandy Clay 2 72.3 – Loamy Sand SP Gravelly Sand 3 43.1 37.2 Sandy Clay SC Silty Clayey Sand 4 64.8 16.2 Sandy Loam SP Gravelly Silty Sand 5 12.6 60.4 Clay CL Sandy Clay 6 31.9 43.3 Sandy Clay CL Silty Sandy Clay 7 40.7 50.0 Clay CL Silty Sandy Clay 8 32.4 41.3 Sandy Clay CL Silty Sandy Clay 9 10.3 80.5 Clay CL Silty Sandy Clay

10 22.7 73.6 Clay ML/CH Sandy Clay 11 18.9 75.4 Clay ML/CH Sandy clay

59

Table 4.12: Unified Soil Classification (after USDA, 1967).

Texture class Soil Group Soil characteristics

Gravel

GW Well-graded gravels; gravel-sand, little or no fines

GP Poorly graded gravels; gravel-sand mixture, little or no fines

GM Silty gravels; poorly graded gravel-sand-silt mixture

GC Clayey gravels; poorly graded gravel-sand-clay mixture

Sands

SW Well-graded sands; gravelly sands, little or no fines

SP Poorly graded sands; gravelly sands, little or no fines

SM Silty sands; poorly graded sand-silt mixture

SC Clayey sands; poorly graded sand-clay mixture

Silts

ML Inorganic silts and fine sands; rock flour, silt or clayey fine sands with slight plasticity

CL Inorganic clays low medium plasticity; gravelly and sandy clays; Silty clays; lean clays

MH Inorganic silt; micaceous or diatomaceous fine sandy or Silty soils; elastic silts

Clays

CH Inorganic clays of high plasticity; fat clay

OH Organic clays of medium to high plasticity

Pt Peat and other highly organic soils

4.4.2.3 Seepage losses Seepage losses are affected more by the prevailing groundwater conditions than by permeable

soils. For example, if an excavation is cut into sandy soil, which lies well above the water table,

water will tend to seep out of the excavation. On the other hand if the water table is higher than

the floor of the excavation, then obviously water will seep in. However, because most storage is

built well above the water table, sands and gravels are likely to be sources of seepage (Lewis,

2001).

There is a simple test was used to evaluate a site. During the site exploration, several soil-

sampling test holes has been dug in the borrow pit areas, these holes are done by hand (30 cm

diameter and at least 70 cm deep) for the seepage tests. 12 tests holes has been carried out; 3 for

each proposed site, the guide described by Nelson (1985) - table 4.13 - was adopted and the

60

results are shown in table 4.14. The following procedure was used in initially testing sub-surface

soils for suitability.

• After excavating holes, each hole was carefully filled to two-thirds its depth with water so

as to saturate the sides of the sub-surface soils.

• When water fills the hole to two-thirds its total depth, the depth to water level below the

ground surface was maintained in each hole. The quantity of water required, and the time

intervals when water is added to maintain this depth, was recorded.

Table 4.13: Guide to site selection based on seepage loss (after Nelson, 1985).

Seepage loss rate (added water –L/hr) Recommendation

< 3 L/hr (ml/min) Site should be satisfactory

3 -30 L/hr (50 -500 ml/min) Site should be regarded as doubtful. This indicates

the need for further tests.

> 30 L/hr (500 ml/min) The site is too permeable for a dam

Table 4.14: seepage test Site Name Test bit No. Seepage loss rate

(L/hr) Average seepage

loss rate Kabus

1 2.7 2.933 2 2.5

3 3.6 Al Ufaynah

1 28.5 34.567 2 36.8

3 38.4 Er Rugutt

1 3.5 2.900 2 2.0

3 3.2 Kurunn

1 3.4 2.767 2 2.1

3 2.8 4.4.2.4 Suitability of the proposed sites Topography, soil and seepage tests have been carried out on all four proposed dam sites (Kabus,

Al Ufaynah, Er Rugutt and Kurunn) to identify their fitness to construct dams. The results have

61

shown that three sites (Kabus, Er Rugutt and Kurunn) are quit fit for dam construction to store

surface water. The other site (Al Ufaynah) can’t be considered as surface storage dam.

4.4.2.5 Artificial recharge site Topographically, the Al Ufaynah site was very satisfying for surface storage, but soil texture

showed the existence of sandy soils which seep the water, and this has been ensured by seepage

test (> 30 L/hr). For this reason the site not proved as surface storage dam and has been proposed

to be artificial recharge site for alluvial aquifer. Detailed structural analysis has been done to

know the rock foliation, dip, fractures and lineaments; then subsurface water flow. Figure 4.6

shows the foliations of rocks at the site are dipping towards the west direction generally and

figure 2.4 shows lineaments of area are trending more or less to WWN direction, so the water

will flow to this direction and the borehole must be drilled west of the dam site.

Fig. 4.6: rose diagram of foliation dip

4.5 Design

Sudanese spend millions of pounds each year on the construction of small dams and Hafirs for

rural communities. This money is wasted because a large proportion of these constructions fail.

The solution to this problem rests in more thorough investigation and improved standards of

design and construction. Unfortunately such proposals are often regarded with apprehension

because many people consider that higher standards mean increased costs.

The combined cost of field investigation and design usually represents only 5 to 10 per cent of

the total capital cost of the dam. Furthermore, if the dam is constructed to a well-designed plan

many cost-saving features can be incorporated. So you may well ask ‘Can I afford the

extravagance of a cheap dam?’

62

4.5.1 Items that need to be considered

An earth-filled dam of any size must be designed so that it is structurally sound and stable during

its operational life. They are simple structures that rely mainly on their mass to resist sliding and

overturning. Modern construction techniques and developments in soil mechanics have greatly

increased the safety and durability of these structures.

According to Lewis (2002), the following design considerations must be met if safety is to be

maintained (Fig. 4.7):

• The batter slopes must be stable and resistant to movement under different operating

conditions, including rapid drawdown.

• The batter slope on the upstream side must be able to handle across-water wave action.

• The earth embankment must be safe from overtopping by both flood inflow and wave

action. This is the reason for providing a 1 m freeboard from full supply level to the top

of the crest.

• Seepage through the embankment and beneath the foundation needs to be controlled to

prevent piping or tunnelling along a line of weakness through, or under the dam.

Fig. 4.7: Cross-section and elevation view (after SRW, 1995).

63

4.5.1.1 Embankment types

4.5.1.1.1 Homogenous Embankment

The earliest small dam embankments were constructed on the principle of a homogenous wall of

earth, whether impervious or not, across waterways or streams, when built properly such

embankments can still be cheap and reliable. However, they are generally inferior to the zoned

embankments described in the next section. This method of construction is simple,

straightforward and suitable for those sites where there is sufficient suitable material. Protection

from seepage and slipping is provided by flattening the downstream batter, that is from a 2:1 to

3:1 gradient (horizontal to vertical), and providing a thick covering of topsoil to carry any

seepage to the toe of the bank. Seepage problems can occur when the dam is constructed on

impervious foundations and comprises:

• Upstream and relatively impervious sections, and the highly impermeable material of the

central core, (which effectively seal the dam against seepage); and

• A downstream segment of poor, coarse material which allows freer drainage of the

embankment and which, by its weight, not only holds the completed wall to its foundation

but also prevents slippage and movement.

4.5.1.1.2 Zoned Embankment

At those sites where there are varying soil materials with widely differing construction

properties, and where high dams are being considered, a zoned embankment should be

considered. Zoned embankments consist of an impervious core/blanket held in place and

protected by a more pervious ‘shell’. The core may be centrally placed, sloping or placed on the

upstream slope in the form of a blanket. A zoned embankment is a better alternative for larger

dams; this allows for the use of construction machinery. Compared with homogenous sections,

costs are likely to be higher, mainly because the earthworks materials are divided into three

categories, that is

• Pervious for the downstream section;

• Impervious for the inner core section; and

• Semi-impervious for the upstream section.

All of these materials need to be excavated from different borrow pits (preferably from within

the storage), thus increasing excavation and movement costs.

64

The use of pervious (sandy) soil materials in the shell can greatly reduce the volume of the

embankment as steeper batters can be used. Upstream blankets are commonly used in

conjunction with lining of the storage area of the dam. For high embankments (greater than 10

m) the use of toe drains and blanket drains allows the downstream slope to be maintained at a

reasonable slope of approximately 3:1 (horizontal : vertical). Without these provisions, much

flatter slopes would be required to maintain slope stability, particularly for clayey soils (fig. 4.8)

With regarding of these two types of embankment and compliance available materials at all

proposed site, in this study zoned embankment must be applied when decided to construct a dam.

4.5.1.2 Core trench

Under the middle of the dam a core trench must be provided to minimize seepage beneath the

dam wall. The core trench should have side slopes no steeper than 1:1 (horizontal to vertical) for

a depth up to 3 m and no steeper than 1.5:1 (horizontal to vertical) for greater depths. The bottom

width of the trench should be 1.5 times the height of the dam, or a minimum width equal to the

width of a bulldozer or scraper. The depth of the core would generally extend to bedrock, or to

an impervious stratum of soil sufficient to prevent excessive seepage beneath the dam. The core

trench material should be placed in layers with a maximum thickness of 100 mm. It is important

that every layer is well compacted.

4.5.1.3 Embankment batter slope

For zoned dams, the following batter slopes are recommended for embankments built of soils

classified according to the Unified Soil Classification system.

The batter slopes for most embankments on strong foundations can be 3:1 (horizontal to vertical)

upstream and 2:1 (horizontal to vertical) downstream. However, flatter batter slopes should be

considered for dams structured on inorganic clay or highly plastic and very fine inorganic silt.

Organic soils are not useable as an embankment material. They tend to be placed on the outside

batters to establish grassy vegetation. They act as a blanket by reducing internal dam moisture

losses. The batter slopes of a dam depend primarily on the stability of the material in the

embankment. The greater the stability of the fill material, the steeper the slopes may be. The

more unstable materials require flatter slopes.

65

Fig. 4.8: Zoned dams with treatment of seepage flow lines for internal drainage (after CDWR, 1986).

66

4.5.1.4 Crest width

The crest width should be (SCA, 1983) increased as the height of the dam increases. The

generally accepted empirical formula for crest width is:-

Crest width (m) = H . + 1

Where H is the height of the crest of the embankment above the bed of the gully in meters.

Lewis (2002) suggested that, the minimum crest width should be about 2.5 m irrespective of H,

so that machinery can work on the crest. Table 4.15 contains recommended top widths for

embankments of various heights based on above formula. Where the top of the embankment is to

be used as a road access track then the top width should provide for a shoulder on each side of

the roadway. The crest width in such cases should not be less than 4 m (figures 4.9, 4.10, 4.11,

and 4.12, Table 4.16).

Table 4.15: Height to crest width.

Dam height (m) Crest width (m)

3 2.75 4 3.00 5 3.25 6 3.50 7 3.65 8 3.85 9 4.00

Table 4.16: proposed dam’s height, crest width, embankment length, fetch distance and freeboard

Proposed

dam

Dam Height

(m)

Crest Width

(m)

Embankment

Length (m)

fetch distance

(m)

Freeboard

(m)

Kabus 10 4.25 713 5300 1.7

Al Afayanh 10 4.25 238 3000 1.5

Er Rugutt 10 4.25 640 5200 1.7

Kurunn 10 4.25 875 5400 1.8

67

Fig. 4.9: cross section of Kabus proposed site

Fig. 4.10: cross section of Al Ufaynah proposed site

Fig. 4.11: cross section of Er Rugutt proposed site

68

Fig. 4.12: cross section of Kurunn proposed site

4.5.1.5 Freeboard

Freeboard is the distance from the top of water to the top of the dam, as a safety factor, to

prevent waves or run-off from storms greater than the design allows from overtopping the

embankment. It comprises the vertical distance between the elevation of the water surface in the

dam, when it is full, and the elevation of the top of the dam after all settlement has taken place. A

large number of dams have failed due to overtopping and consequently greater attention must be

paid to this feature. Freeboard should not be less than 1.0 m (table 4.17) and should include

provision for:

I. depth of flood surcharge to pass water through the spillway;

II. wave action, which can be calculated from Hawksley’s formula:

H = 0.0138√F

Where H = wave height in meters,

F = fetch distance (the longest exposed water surface in meters).

Figure 4.13 and 4.14

III. An additional allowance of 0.3 m for unevenness in the crest level.

Using these provisions:

퐹푟푒푒푏표푎푟푑(푚) = 푑푒푝푡ℎ 표푓 푓푙표표푑 푠푢푟푐ℎ푎푟푔푒 + 푤푎푣푒 푎푐푡푖표푛 + 0.3

69

Fig.4.13: wave action (after Lewis, 2002)

Fig. 4.14: Wave actions based on fetch distance across the storage

70

Table: 4.17: Freeboard values for various fetches (after Stephens, 1991)

Fetch (m) Freeboard (m)

Up to 600 1.0

1000 1.2

2000 1.3

3000 1.5

4000 1.6

5000 1.7

4.5.1.6 Alternative ways of batter protection

A small dam should not be considered complete until proper protection from erosive wave

action, livestock and other sources of damage has been provided. Dams that lack such protection

may be short-lived, and the cost of maintenance is usually high. In most areas, the exposed

surfaces of the dam, spillway, borrow areas and other disturbed surfaces can be protected against

erosion by establishing a good cover of sod-forming grass. Occasionally, there is a need for

better protection against wave action than will be provided by grass cover. Methods used to

provide this protection include earth berms, log booms, and rock riprap.

4.5.1.6.1 Berms

A berm, 2.5 to 3 m in width and located at normal dam level, will often provide adequate

protection from wave action. The face of the dam above the berm should be protected by

vegetation.

4.5.1.6.2 Floating booms

A boom may consist of a single or double line of pine logs chained together and securely

anchored to each end of the dam. The boom should be tied end-to-end as close together as

practical. There should be enough slack in the line to allow the boom to adjust itself to

fluctuating levels in the dam. Double rows of logs should be framed together to act as a unit. The

boom should be placed in order to float about 1.5 m upstream from the face of the dam for best

results. In the case of a curved dam, anchor posts may be required at the ends in order to prevent

the boom from riding on the slope. Booms afford a high degree of protection and are relatively

inexpensive, especially in areas where timber is readily available.

71

4.5.1.6.3 Rock-beaching (Riprap)

Where the water level in the dam can be expected to fluctuate widely, or where a high degree of

protection is required, the use of rock-beaching is a most effective method of control (Figure

4.15). Rock-beaching should extend from the top of the dam, down the upstream face to a level

at least 1 meter below the lowest expected level of the water in the dam. Rock-beaching may be

placed by machine or by hand. Machine placing requires more stone but less labour. The layer of

stone should be durable and large enough not to be displaced by waves. Where rock beaching is

not continuous with the upstream toe, a berm should be provided on the upstream face to support

the layer of rock-beaching. In some circumstances graded gravel filters may be required under

the rock-beaching layer.

4.5.1.7 Topsoil cover

Prior to the placement of topsoil onto the compacted embankment, the surface should be

roughened to assist in combining the different soil types. Topsoil must be placed over the entire

embankment to a depth of at least 100 to 150 mm and grassed with a good holding grass. The

purpose of the topsoil cover is to:

• reduce surface erosion on either side of the batter slope;

• minimize surface cracking in the embankment;

• lessen the tendency of the surface material in contact with storage water being dispersed;

and

• Lessen wide fluctuations in embankment moisture content.

4.5.1.8 Fencing

The complete fencing of embankment type dams is recommended where livestock are grazed or

fed in adjacent areas. Fencing provides the protection needed to develop and maintain vegetation

cover. When combined with a water facility below the dam, fencing allows good quality drinking

water and eliminates the danger of pollution by livestock.

72

Fig. 4.15: Typical rock-beaching (after USDA, 1969)

4.5.2 Outlet structures

There are various types of components, storm run-off, compensation flows and environmental

flows that are incorporated into an embankment to allow for the passing of water flows under a

license condition. Some of the common ones are explained in the rest of this section. The tables

and information provided should only be used as a guide in the selection of sizes of pipes and

spillway dimensions. It should be remembered that these numbers are not necessarily applicable

to all cases. They are general values rather than site-specific.

4.5.2.1 Spillways

Spillway is an earth or concrete channel, designed to discharge the peak flow calculated for the

catchment. Where catchments are small and long duration flows are not a problem, it may be

feasible to handle the run-off safely with only a vegetated spillway.

Spillways, as discussed here, apply to concrete spillways (figure 4.16 and 4.17), the latter being

used where climatic or soil conditions make it impossible to grow or maintain a suitable grass

cover. Spillways are usually excavated, but may exist as a natural spillway on a well-vegetated

saddle or drainage line. In either case, the spillway must discharge the design peak flow at a non-

erosive velocity to a safe point of release. Spillway structures have certain limitations. They

should be used only where the soils and topography permit safe discharge of the peak flow at a

point well away from the dam at a velocity that will not cause appreciable erosion. Temporary

73

flood storage provided in the dam has been used to reduce the design flow or frequency of use in

the spillway, if a trickle pipe is incorporated in the design.

Fig. 4.16: Sketch of spillway

Fig. 4.17: Spillway cross section

4.5.2.2 Pipelines through embankments

Pipelines (figure 4.18 below) are often placed through or under embankments for any of the

following purposes:

• To provide a gravity supply from the storage;

• As a suction pipe for a pumped supply (this always maintains a positive prime to the

pump);

74

• To maintain flow downstream from the storage; and

• To bypass a significant flood-flow through a piped spillway.

Fig. 4.18: Pipeline through embankment

Pipelines may be constructed using reinforced concrete pipes (rubber-ring joints), cement-lined

cast iron pipes, galvanized or black steel pipes, high density polyethylene or PVC pipes. Special

care needs to be taken with joining of rubber-ring jointed pipes. An anchor block at the outlet

valve is essential to avoid movement of the pipes. If concrete pipes are used, the class of the pipe

suitable for the depth of fill above must be used. PVC is liable to brittle fracture if impacted by

construction equipment. All pipes should be pressure-tested to check welds, joints and seams on

placing. In addition, a further test may be required after covering the pipe is completed, taking

into account:

• The proposed full supply level;

• The superimposed load on the pipe;

• permit conditions if applicable; and

• Siltation of the entry.

75

4.6 Water management

A dam should be fenced and protected in order to keep entering by human or animal, Fencing

should include the silt retention area in order the community be able to manage the whole

available water source and to minimize pollution and hygiene hazards during storage and

abstraction. D The current experience of fencing is the use of angle irons posts and barbed wire

mesh. Some states are not comfortable with this type of fencing as the openings allow access to

small stocks. They prefer the prefabricated mesh wire instead. Water supply to the community

and their stocks should be through out irrigation system as described in figure 4.19 for raw water

sources from rain water harvesting.

Fig. 4.19: Schematic flow diagram for raw water source from rain water harvesting

76

4.7 Environmental significance of the dam project

Before the commencement of the project there was an Environmental Impact Assessment of the

project at the design stage to enhance its environmental sustainability and in fulfillment of the

statutory required. An environmental audit of the project revealed that, most of the probable

impacts identified are:

4.7.1 Positive Impacts 4.7.1.1 Flood Water Control The dam has significantly reduced flood water flow around the Study area environment. This is

because the collection of the hillside runoff in the impoundment greatly dissipates it of its

erosive energy thereby rendering it less erosive and less degrading to the soil resources in the

area. There has been a significant reduction in the devastation to household and structures due to

the flooding incidences especially during the rainy seasons. Also the ever increasing fear of

flooding and its devastations on the on set of the rainy seasons has seriously decreased as so is

the risk of flooding.

4.7.1.2 Water Supply to the Community Water Supply to the Community through the surface impoundment will provide more reliable

water availability all year round to the study area community. Even though the ground water

supply through the use of hand pumps is relatively available, the problems of servicing the hand

pumps rendered them inadequate when a break down occurs. The present water treatment system

ensures a more wholesome (healthy) and dependable water to the community in the present and

into the future. It will significantly reduce incidences of water borne diseases like dysentery with

and dysentery without blood.

4.7.1.3 Improvement in the Streams Biology The impoundment of the water in the reservoir will make water to be available all year round

despite the level of sediment load. As a result there is a gradual generation of all year round

aquatic ecosystem within the impoundment thereby encouraging the development of relevant

benthic fauna and flora, both in quality and quantity in the reservoir and upstream, which could

not have been possible without the reservoir due to the relative dryness of the stream for parts of

the year. Also perennial nature of the impoundment is encouraging the growth and development

of a viable riparian ecosystem which will include micro- and macro- organisms including fishes

and their supporting invertebrates. Ultimately fish development will increase to support regulated

77

fishing as long as it does not compromise the integrity of the reservoir water as a drinking water

source.

4.7.1.4 Improvement of Agricultural Production The development of irrigation activities on down stream of the reservoir is enabling the

cultivation of more crops and additional area of land to increase rain fed agricultural production.

The increased production will contribute to increased revenue to the average farming family,

enhance their purchasing power, their standard of living and in the long run ensure food security

for the nation. Also available will resulted in more water available for the livestock industry.

This is further enhancing agricultural productivity and an improvement in national food security.

4.7.1.5 Sustenance of Wild Life and Recharge of Groundwater The presence of the body of water on a perennial basis will attract wild life to the area for their

water need. With the wooded hills in close proximity, an appropriate sanctuary is being

developed around the lake reservoir and thus enhancing the propagation of valuable species of

wild life. It is also possible that different birds of different types and sizes will be attracted to the

area including migratory ones. With the lake reservoir in place, there will be a gradual recharge

of the ground water resources through intra-profile seepage. There will be gradual upward rise of

the water table for a greater part of the year.

4.7.2 Adverse Impacts 4.7.2.1 Downstream Ecology The operation of the dam has significantly reduced flow of water down stream especially after

the cessation of the spillway, such that subsequently the habitats and riparian forests downstream

may subsequently be affected. It is also possible that non riparian species may gradually be

encroaching into the riparian domain down stream of the dam embankment. Close examination

has shown that because of the numerous tributaries to the many streams to which they drains; the

likelihood of this occurrence in the immediate future is not foreseen. This is because as the

gradual starvation of the down stream sets in, tributary recharge will minimize the immediate

shock of the reduced flow until seepage beneath the dam becomes a major portion of the stream

flow. This will create an insignificant impact in the long run. Also, the planted riparian species of

trees upstream of the reservoir as protector of the lake shoreline will compensate against any loss

in biodiversity of the riparian species.

78

4.7.2.2 Close Proximity as Source of Danger and Risk of Drowning The close proximity of the proposed reservoirs to the many small villegs is a potential source of

risk to the community. This is because the inhabitants face the risk of drowning in the reservoirs

as living quarters are less than I kilometer from the reservoir periphery. The reservoirs shore

must properly fenced; the risk to life posed by the reservoirs will be minimal as some form of

restriction has been put in place to restrain the populace from unguarded contact with the

reservoir. Also, regular awareness and publicity should be regularly mounted to enlighten the

community of the inherent danger of drowning and hence guard against carelessness within this

restricting fence.

4.7.2.3 Increase in the Population of Mosquitoes and Black Flies The body of water is an attractive breeding ground to mosquitoes with the attendant increase I n

incidence of malaria and yellow fever in the community. The introduction of malophagous

species of fish species like Clarias gariepinus and Synodontis species and larvivorous species

like Gambusia affinis and Lebistes reticulates in the reservoirs will check snail and mosquito

populations in the reservoir removing the threat of mosquitoes and black flies that could make

the diseases of malaria and schistosomiasis endemic. Further more regular weed control at the

reservoir edge will prevent the breeding of the mollusks and mosquitoes.

4.8 Sedimentation 4.8.1 Introduction

Sediment yield refers to the amount of sediment exported by a basin over a period of time, which

is also the amount which will enter a reservoir or pond located at the downstream limit of the

basin (Morris and Fan, 1998). Estimate of long-term sediment yield have been used for many

decades to size the sediment storage pool and estimate reservoir life. However, these estimates

are often inaccurate especially for small catchments. Besides, it is known from literature that

long term period sampling programmes are required to capture the high variability of sediment

fluxes in these catchments (Horowitz, 2004). The correlation of sediment yields to erosion is

complicated by problem of determining the sediment delivery ratio, which makes it difficult to

estimate the sediment load entering a reservoir/pond on the basis of erosion rate within the

catchment (Morris and Fan, 1998). Sediment yield from the dam catchment is one of the

parameters controlling sedimentation of small dams. This has to be estimated if future

sedimentation rates in a dam are to be predicted.

79

Reservoirs re-survey data are available from a large number of authors for over 300

impoundments world-wide and serve as a useful guide to global sediment yield figures. The

majority of these data originated from the USA, with remainder from India, Equador, China,

Australia and Africa. These data have been broadly categorized on a continental basis in table

(4.18).

Table 4.18: Sediment yield data from reservoir surveys

Region Sediment yield (t/Km2/yr)

Americas 1104

Africa 259

Asia 293

Europe 126

The siltation is a rather minor problem for many dams but may reduce by decades the possible

long life of 50 % of them and may be a key problem within few years or few decades for over

10% of large or small dams.

The cost efficiency of various solutions for siltation mitigation has varied greatly and it is not

easy to optimize their choice because the local data are never the same and the likely siltation

rate itself may hardly be known precisely before some years of dam operation.

4.8.2 Main impacts of reservoirs sedimentation

4.8.2.1 Storage loss

It is usually the main impact for dams devoted to water storage as their benefit is quite

proportional to the storage. Their benefit may possibly be reduced by fewer than 20% when the

reservoir is 80% filled (including a large part in the designed dead storage).

4.8.2.2 Turbines abrasion:

Sediment coarser than 0.1 mm may greatly accelerate the erosion of turbines parts; even smaller

grain sizes may cause damages if containing quartz. Also sediment concentration and total head

are important factors.

80

4.8.2.3 Downstream impacts

Stream reaches downstream of dams suffer large environmental impacts due to flow changes,

reduction of sediment load, altered nutrient dynamics, temperature changes, and the presence of

the migration barrier imposed by the structure and the upstream impoundment (fig. 4.20).

Clear water released from the reservoir will cause down stream erosion and possibly bank

failures.

Fig. 4.20: Plan view and vertical cross section for a conceptualized dammed watershed. The t = notation

is used to represent different time (after Heppner and Loague 2008).

4.8.2.4 Concepts of Reservoir Life

With reasonable levels of maintenance, the structural life of dams is virtually unlimited, and

most reservoirs are designed and operated on the concept of a finite life which will ultimately be

terminated by sediment accumulation rather than structural obsolescence.

Design life is the planning period used for designing the reservoir project. Planning and

economic studies are typically based on a period not exceeding 50 years, whereas engineering

studies often incorporate a 100-year sediment storage pool in the design.

81

The target of a very long reservoir life should be a key point of a right design and management

of siltation problems.

4.8.3 Reservoir sedimentation management

4.8.3.1 Sediment trapping upstream of the dam

There are only two strategies to reduce the sediment yield entering a reservoir: either prevent

erosion or trap eroded sediment before it reaches the reservoir.

The rehabilitation of some watersheds can dramatically reduce the rate at which sediment,

nutrients, and other contaminants are delivered to a reservoir.

An efficient proposed option was the construction of upstream reservoirs that will act only as

sediment retention structures.

4.8.3.2 Sediment Routing

Sediment routing includes any method to manipulate reservoir hydraulics, geometry, or both, to

pass sediment through or around reservoir or intake areas while minimizing objectionable

deposition. Routing is the most environmentally benign sediment management strategy.

Sediment routing techniques include sediment passing through and sediment by pass.

4.8.3.3 Sediment passes through

It may be by seasonal drawdown, by drawdown adapted to floods or by turbidity currents. This

requires initial implementation of the necessary bottom gates to be designed with great care. A

reservoir operated under seasonal drawdown is either partially or completely emptied during the

beginning of flood season. Seasonal drawdown is conducted during a predetermined period each

year, as opposed to flood routing, which requires that the reservoir level be drawn down for

individual flood events when they occur. At some sites routing can be implemented at very low

cost.

A major disadvantage of sediment routing is that a significant amount of water must be released

during floods to transport sediments. Sediment routing is most applicable at hydrologically small

reservoirs where the water discharged by large sediment-transporting floods exceeds the

reservoir capacity, making water available for sediment release without infringing on beneficial

uses.

82

4.8.3.4 Sediment Bypass for Reservoirs

When topographic conditions are favourable (for this reason also the site selection is important),

a large-capacity channel or tunnel can be constructed to bypass sediment-laden flow around the

reservoir or part of it. It may be built initially and possibly used for flood control during

construction. Most may also be built according to precise needs after years or decades of

operation. Such tunnel may be associated with a low dam in the upstream part of the reservoir. It

may bypass some hundred m3/s or even thousand m3/s of water. This solution may have much

future for large schemes.

4.8.3.5 Sediment flushing

Hydraulic flushing involves reservoir drawdown by opening a low-level outlet to temporarily

establish riverine flow along the impounded reach, eroding a channel through the deposits and

flushing the eroded sediment through the outlet.

Unlike sediment routing, which attempts to prevent deposition during flood events, flushing uses

drawdown and emptying to scour and release sediment after it has been deposited. Usually

flushing is less efficient if the sediment is coarse or is consolidated clay materials.

The width of a flushing channel within sediments is often in the range of 100 m and may reach

few hundred m; flushing is thus much more efficient in narrow valleys.

4.8.3.6 Managing the silt storage

It is usually difficult to drawdown completely the large hydropower reservoirs but it is usually

possible to drawdown the reservoir by 20 % or 30 % at the flood time in order to store the

sediment in the dead storage and to pass through most sediment when the dead storage is full.

Corresponding gates may be 20 to 50 m under the dam crest.

Turbines abrasion may be a key problem for high head hydropower and many desilting

underground chambers along head race tunnels designed for avoiding it proofed costly and

poorly efficient. It may be possible to design the reservoir itself as a desilting structure upstream

of the entrance of the head race to the power house. This solution which is presented in the

ICOLD Bulletin 144 appears very promising. The stored sediment may be flushed from time to

time or dredged permanently.

83

4.8.3.7 Removing stored sediment:

Sediment deposits may be mechanically removed from reservoirs by dry excavation or hydraulic

dredging and hydro-suction. The annual worldwide stored sediment is close to 40 Billion m3;

possibly half is in the designed dead storage.

All methods of mechanical excavation are costly because of the large volumes of material

involved and, frequently, the difficulty of obtaining suitable sites for placement of the excavated

material within an economic distance of the impoundment. However, once sediments are

deposited in a reservoir, excavation may be the best management option available.

4.8.4 Siltation may be a key problem of many reservoirs

The design of such dams including the site choice and layout should be linked with it. It is

necessary to investigate following items for sediment treatment in reservoir:

To measure efficiently the sediment load.

To evaluate the cost of sediment in long term at the time of planning dam structure.

To select most suitable sediment treatment method with consideration of topography and

flows of river, effectiveness, economical, environmental and various conditions with

overall judgment.

To apply, not only one, but several measures in rivers with great volume of sediment, such

as sediment routing, bypassing, dredging, or measures to origin of occurrence upstream of

dam.

To apply measures for sediment with coordination of several reservoirs of one area or

basin.

In the near future, strategic dam asset management including preventive countermeasures

for reservoir sedimentation will be an important challenge.

The sediment in dams is critical. Leaving sediment management as it is may lead to not only

reduction but full loss of reservoir functions. With proper treatment of sediment, it is possible to

maintain its function economically along centuries.

Since the progress of sedimentation is slow in general, part of solutions may possibly be delayed

but the long term possible solutions should be analyzed initially and partly implemented from the

beginning: they may thus impact the full design.

84

CHAPTER FIVE

CONCLUSION AND RECOMMENDATION

85

CHAPTER FIVE CONCLUSION AND RECOMMENDATION

5.1 Conclusion

The results of Digital Elevation model study (DEM) had shown that, the survey area represented

by different topographic terranes varying from hilly to peniplains and its rises varying from a

500 m above mean sea level to 1050 m. this figure is very useful in rain water harvesting projects

which need topographical variation.

A Geographic Information System (GIS) applications which used to delineate watersheds;

performed drainage analysis on a terrain model and revealed several watersheds. A geometric

network is constructed and in compliance with DEM results; four watersheds were selected to be

investigated in more detailed.

Geology study showed wide distribution of clay soil as soil cover, underlying by crystalline

rocks. This soil, represent one of surface storage aspects. Structural analysis including foliation

strike, dip and fractures has been carried out and the modeling showed general dip and strike

directions. This result is very fruitful in subsurface storage.

Soil texture tests on four proposed sites, emphasized clayey soil, silty clay soil and sandy silty

clay soil in Kabus, Er Rugutt and Kurunn sites, these soil may hold water in case of surface

storage. Clayey sand and gravelly silty sand soil had been detected in Al Ufaynah sites, these

soils may not be water holding soils.

Seepage tests throughout the proposed sites showed the average seepage loss in Kabus Site 2.933

L/hr, Al Ufaynah site 34.567 L/hr, Er Rugutt site 2.900 L/hr and Kurunn site 2.767 L/hr. these

results indicates that Al Ufaynah Site is suitable for subsurface storage and the other three sites

for surface storage.

Cross section of proposed dams along its axis showed; possibility of constructing dam up to 10

meter height in all four sites with variations in embankment Distance from site to another, as 713

meter for Kabus, 238 meter for Al Ufaynah, 670 meter for Er Rugutt and 875 meter for Kurunn.

Freeboard is 1.7 m for Kabus, 1.5 m for Al Ufaynah, 1.7 m for Er Rugutt and 1.8 m for Kurunn.

86

Fetch distance is 5300 m Kabus, 3000 m for Al Ufaynah, 5200 m for Er Rugutt and 5400 m for

Kurunn.

5.2 Recommendation

More detailed survey of population and their house stocks uses, farms and animals is needed, in

order to perform water demands.

More hydrological data including rainfall, evaporation and runoff from different stations is

required to calculate the expected water availability.

Geophysical works are needed to determine the alluvial aquifer geometry, to find out how much

water we can store for subsurface dam.

Long term water quality analysis of stored flood water is must be carried on.

There are very small villages scattered in the area, so selection of favorable areas for collection

of these small villages must study.

87

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93

Appendix A:

Dip and strike of foliation:

Strike Dip Strike Dip

Amount Direction Amount Direction

11 70 NW 95 20 NE

13 64 NW 23 50 NW

95 20 NE 16 75 NW

20 73 NW 30 65 NW

18 67 NW 28 60 NW

15 58 NW 25 57 NW

19 65 NW 29 50 NW

98 23 SW 32 54 NW

22 45 NW 20 66 NW

21 48 NW 23 56 NW

05 55 NW 90 20 N

08 57 NW 85 15 NW

06 60 NW 30 38 NW

07 57 NW 25 30 NW

14 40 NW 20 48 NW

13 37 NW 12 50 NW

17 40 NW 10 44 NW

23 80 NW 08 75 NW

25 75 NW 17 45 NW

94

Dip and strike of foliation:

Strike Dip Strike Dip

Amount Direction Amount Direction

10 75 NW 90 20 N

14 60 NW 20 60 NW

85 20 NW 18 70 NW

10 73 NW 20 65 NW

23 67 NW 38 60 NW

25 58 NW 15 57 NW

09 65 NW 39 50 NW

93 23 SW 37 54 NW

20 45 NW 18 66 NW

19 48 NW 22 56 NW

15 55 NW 100 20 NE

18 57 NW 85 15 NW

16 60 NW 40 38 NW

07 57 NW 25 30 NW

14 40 NW 20 48 NW

13 37 NW 12 50 NW

17 40 NW 10 44 NW

13 70 NW 18 65 NW

15 65 NW 27 51 NW

95

Dip and strike of foliation:

Strike Dip Strike Dip

Amount Direction Amount Direction

22 60 NW 85 20 NW

18 65 NW 33 50 NW

75 20 NW 26 75 NW

25 75 NW 30 35 NW

28 65 NW 20 60 NW

05 68 NW 20 57 NW

29 55 NW 25 40 NW

100 20 SW 30 54 NW

10 45 NW 20 66 NW

11 58 NW 33 56 NW

15 45 NW 80 20 NW

18 47 NW 75 15 NW

16 60 NW 40 38 NW

07 57 NW 25 30 NW

14 40 NW 20 48 NW

13 37 NW 12 50 NW

27 40 NW 10 54 NW

13 80 NW 18 75 NW

30 70 NW 10 45 NW

96

Appendix B:

Soil Mechanical Analysis

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 15 2.693 2.6929982 97.3070018

0.5 34.3 6.15799 8.8509874 91.14901257 0.25 46.7 8.3842 17.235189 82.76481149

0.125 50.3 9.03052 26.265709 73.73429084 0.063 95.7 17.1813 43.447038 56.5529623 pan 315 56.553 100 0

Total 557 Kabus 1

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 10 1.87617 1.8761726 98.12382739

0.5 30.3 5.6848 7.5609756 92.43902439 0.25 36.7 6.88555 14.446529 85.55347092

0.125 40.3 7.56098 22.007505 77.99249531 0.063 95.7 17.955 39.962477 60.03752345 pan 320 60.0375 100 0

Total 533 Kabus 2

diameter soil retained percent retained percent cumulative percent passing 2 40.7 8.56301 8.5630128 91.43698717 1 43.6 9.17315 17.736167 82.26383337

0.5 30.3 6.37492 24.111088 75.88891227 0.25 36.7 7.72144 31.832527 68.16747317

0.125 40.3 8.47886 40.311382 59.68861772 0.063 63.7 13.4021 53.713444 46.28655586 pan 220 46.2866 100 0

Kabus 3

97

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 0 0 0 100

0.5 45.3 8.0035336 8.003533569 91.996 0.25 66.7 11.784452 19.78798587 80.212

0.125 50.3 8.8869258 28.67491166 71.325 0.063 83.7 14.787986 43.46289753 56.537 pan 320 56.537102 100 0

Total 566 Kabus 4

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 0 0 0 100

0.5 45.3 8.66654 8.6665391 91.33346088 0.25 66.7 12.7607 21.427205 78.5727951

0.125 50.3 9.62311 31.050316 68.94968433 0.063 3.7 0.70786 31.758179 68.24182131 pan 356.7 68.2418 100 0

Total 522.7 Kabus 5

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 0 0 0 100

0.5 35.3 6.88512 6.885118 93.114882 0.25 46.7 9.10864 15.993759 84.00624147 0.125 40.3 7.86035 23.854106 76.14589429 0.063 33.7 6.57304 30.42715 69.57284962 pan 356.7 69.5728 100 0

Total 512.7 Kabus 6

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 0 0 0 100

0.5 45.3 8.58442 8.584423 91.41557703 0.25 52.7 9.98673 18.571158 81.42884215

0.125 70.3 13.322 31.893121 68.10687891 0.063 2.7 0.51165 32.404775 67.59522456 pan 356.7 67.5952 100 0

Total 527.7 Kabus 7

98

diameter

soil retained percent retained percent cumulative

percent passing 2 35.9 7.4745 7.4744951 92.52550489 1 40.7 8.47387 15.948366 84.0516344

0.5 45.3 9.43161 25.379971 74.62002915 0.25 52.7 10.9723 36.35228 63.64772017

0.125 70.3 14.6367 50.988965 49.01103477 0.063 18.7 3.8934 54.882365 45.11763481 pan 216.7 45.1176 100 0

Total 480.3 Kabus 8

diameter soil retained percent retained percent cumulative percent passing 4 15.7 4.28962 4.2896175 95.71038251 2 35.9 9.80874 14.098361 85.90163934 1 40.7 11.1202 25.218579 74.78142077

0.5 45.3 12.377 37.595628 62.40437158 0.25 52.7 14.3989 51.994536 48.00546448

0.125 70.3 19.2077 71.202186 28.79781421 0.063 18.7 5.10929 76.311475 23.68852459 pan 86.7 23.6885 100 0

Total 366 Kabus 9

diameter soil retained percent retained percent cumulative percent passing 4 11 1.9 1.9 98.1 2 47 22.7 24.6 75.4 1 43 20.8 45.4 54.6

0.5 20 9.7 55.1 44.9 0.25 12 5.8 60.9 39.1

0.125 23 11.1 72 28 0.063 58 28 100 0 pan 214 100

Al Ufaynah 2

diameter soil retained percent retained percent cumulative percent passing 4 47 8.561020036 8.561020036 91.43897996 2 58 10.56466302 19.12568306 80.87431694 1 32 5.828779599 24.95446266 75.04553734

0.5 62 11.29326047 36.24772313 63.75227687 0.25 48 8.743169399 44.99089253 55.00910747

0.125 39 7.103825137 52.09471767 47.90528233 0.063 77 14.02550091 66.12021858 33.87978142 pan 186 33.87978142 100 0

99

Al Ufaynah 3

diameter soil retained percent retained percent cumulative percent passing 2 42 8.64198 8.6419753 91.35802469 1 32 6.58436 15.226337 84.77366255

0.5 30 6.17284 21.399177 78.60082305 0.25 17 3.49794 24.897119 75.10288066

0.125 53 10.9053 35.802469 64.19753086 0.063 89 18.3128 54.115226 45.88477366 pan 223 45.8848 100 0

Total 486 Al Ufaynah 4

diameter soil retained percent retained percent cumulative percent passing 2 42 7.5539568 7.553956835 92.446 1 80 14.388489 21.94244604 78.058

0.5 44 7.9136691 29.85611511 70.144 0.25 22 3.9568345 33.81294964 66.187

0.125 53 9.5323741 43.34532374 56.655 0.063 92 16.546763 59.89208633 40.108 pan 223 40.107914 100 0

556 Al Ufaynah 5

diameter soil retained percent retained percent cumulative percent passing 2 10 1.88857 1.8885741 98.11142587 1 15 2.83286 4.7214353 95.27856468

0.5 45.8 8.64967 13.371105 86.62889518 0.25 66.7 12.5968 25.967894 74.03210576 0.125 53 10.0094 35.977337 64.02266289 0.063 89 16.8083 52.785647 47.21435316 pan 250 47.2144 100 0

Al Ufaynah 6

diameter soil retained percent retained percent cumulative percent passing 2 5 1.04058 1.0405827 98.95941727 1 15 3.12175 4.1623309 95.83766909

0.5 45.8 9.53174 13.694069 86.30593132 0.25 56.7 11.8002 25.494277 74.5057232 0.125 53 11.0302 36.524454 63.47554631 0.063 15 3.12175 39.646202 60.35379813 pan 290 60.3538 100 0

Total 480.5 Al Ufaynah 7

100

diameter soil retained percent retained percent cumulative percent passing 2 15 2.87081 2.8708134 97.1291866 1 30 5.74163 8.6124402 91.38755981

0.5 45.8 8.76555 17.37799 82.62200957 0.25 56.7 10.8517 28.229665 71.77033493

0.125 70 13.3971 41.626794 58.37320574 0.063 15 2.87081 44.497608 55.50239234 pan 290 55.5024 100 0

Total 522.5 Al Ufaynah 8

diameter soil retained percent retained percent cumulative percent passing 4 63.8 17.4317 17.431694 82.56830601 2 36.9 10.0847 27.516417 72.48358341 1 54.8 14.9768 42.493186 57.5068138

0.5 58.9 16.0973 58.590481 41.40951946 0.25 53.8 14.7035 73.293951 26.70604856 0.125 97.7 26.7013 99.995236 0.00476406 0.063 0 0 100 0 pan 0 0 0 100

Total 365.9 Rugut 1

diameter soil retained percent retained percent cumulative percent passing 2 35.9 6.08165 6.0816534 93.9183466 1 40.7 6.8948 12.976453 87.02354735

0.5 45.3 7.67406 20.650517 79.34948331 0.25 52.7 8.92766 29.578181 70.42181941

0.125 70.3 11.9092 41.487379 58.5126207 0.063 28.7 4.86193 46.349314 53.65068609 pan 316.7 53.6507 100 0

Total 590.3 Rugut 2

diameter soil retained percent retained percent cumulative percent passing 2 25.9 4.58164 4.5816381 95.41836193 1 76.7 13.568 18.149655 81.85034495

0.5 63.3 11.1976 29.347249 70.65275075 0.25 72.7 12.8604 42.207677 57.79232266 0.125 81.3 14.3817 56.589422 43.41057845 0.063 28.7 5.07695 61.666372 38.33362816 pan 216.7 38.3336 100 0

Total 565.3

101

diameter soil retained percent retained percent cumulative percent passing 2 2.9 0.51574 0.5157389 99.48426107 1 16.7 2.96994 3.4856838 96.5143162

0.5 23.3 4.1437 7.6293793 92.37062067 0.25 92.7 16.4859 24.115241 75.88475903 0.125 81.3 14.4585 38.573715 61.4262849 0.063 8.7 1.54722 40.120932 59.87906811 pan 336.7 59.8791 100 0

Total 562.3 Rugut 4

diameter soil retained percent retained percent cumulative percent passing 2 2.6 0.4683 0.4682997 99.53170029 1 15.2 2.73775 3.2060519 96.79394813

0.5 21.3 3.83646 7.0425072 92.9574928 0.25 91.7 16.5166 23.559078 76.44092219

0.125 81.3 14.6434 38.20245 61.79755043 0.063 7.7 1.38689 39.589337 60.41066282 pan 335.4 60.4107 100 0

Total 555.2 Rugut 5

diameter soil retained percent retained percent cumulative percent passing 2 3.8 0.67209 0.6720906 99.32790944 1 14.2 2.5115 3.1835868 96.81641316

0.5 22.3 3.94411 7.1276972 92.87230279 0.25 81.7 14.4499 21.577644 78.42235585

0.125 73.3 12.9643 34.541917 65.45808277 0.063 24.7 4.36859 38.910506 61.08949416 pan 345.4 61.0895 100 0

Total 565.4 Rugut 6

diameter soil retained percent retained percent cumulative percent passing 2 11.8 2.37712 2.3771152 97.62288477 1 27.2 5.47945 7.8565673 92.14343272

0.5 42.3 8.52135 16.377921 83.62207897 0.25 71.7 14.444 30.821918 69.17808219

0.125 73.3 14.7663 45.588235 54.41176471 0.063 24.7 4.97583 50.564061 49.43593876 pan 245.4 49.4359 100 0

Total 496.4 Rugut 7

102

diameter soil retained percent retained percent cumulative percent passing 2 5.8 1.09351 1.0935143 98.90648567 1 27.2 5.12821 6.2217195 93.77828054

0.5 32.3 6.08974 12.311463 87.68853695 0.25 41.7 7.86199 20.173454 79.826546

0.125 53.3 10.049 30.222474 69.7775264 0.063 24.7 4.65686 34.879336 65.12066365 pan 345.4 65.1207 100 0

Total 530.4 Kurunn 1

diameter soil retained percent retained percent cumulative percent passing 4 53.8 14.6995 14.699454 85.30054645 2 46.9 12.8177 27.517163 72.48283669 1 54.8 14.9768 42.493933 57.50606708

0.5 58.9 16.0973 58.591227 41.40877274 0.25 53.8 14.7035 73.294698 26.70530185

0.125 97.7 26.7013 99.995983 0.004017342 0.063 0 0 100 0 pan 0 0 0 100

Total 365.9 Kurunn 2

diameter soil retained percent retained percent cumulative percent passing 2 6.8 1.2091 1.2091038 98.79089616 1 28.2 5.01422 6.2233286 93.77667141

0.5 33.3 5.92105 12.144381 87.85561878 0.25 45.7 8.12589 20.27027 79.72972973

0.125 58.3 10.3663 30.636558 69.36344239 0.063 24.7 4.39189 35.02845 64.9715505 pan 365.4 64.9716 100 0

Total 562.4 Kurunn 3

103

diameter soil retained percent retained percent cumulative percent passing 4 43.8 11.9672 11.967213 88.03278689 2 46.7 11.127 23.094209 76.90579141 1 54.3 12.9378 36.032021 63.96797869

0.5 58.5 13.9385 49.970549 50.02945117 0.25 53.8 12.8187 62.789229 37.21077116

0.125 97.2 23.1594 85.948628 14.05137159 0.063 65.4 15.5826 100 0 pan 0 0 0 0

Total 419.7 Kurunn 4

diameter soil retained percent retained percent cumulative percent passing 2 6.8 1.42737 1.427372 98.57262804 1 12.2 2.56087 3.9882452 96.01175483

0.5 13.3 2.79177 6.7800168 93.21998321 0.25 15.7 3.29555 10.075567 89.92443325

0.125 28.3 5.94039 16.015953 83.98404702 0.063 24.7 5.18472 21.200672 78.7993283

pan 375.4 78.7993 100 0 Total 476.4

Kurunn 5

diameter soil retained percent retained percent cumulative percent passing 2 16.7 3.44259 3.4425892 96.55741084 1 142 29.2723 32.714904 67.28509586

0.5 22.3 4.59699 37.311894 62.68810555 0.25 35.7 7.35931 44.671202 55.32879819 0.125 28.3 5.83385 50.505051 49.49494949 0.063 24.7 5.09173 55.596784 44.40321583 pan 215.4 44.4032 100 0

485.1 Kurunn 6

diameter soil retained percent retained percent cumulative percent passing 2 10.7 1.97672 1.9767227 98.0232773 1 14.2 2.62331 4.6000369 95.39996305

0.5 42.3 7.81452 12.414558 87.58544245 0.25 55.7 10.29 22.7046 77.29539996

0.125 58.3 10.7704 33.474968 66.52503233 0.063 44.7 8.2579 41.732865 58.26713468 pan 315.4 58.2671 100 0

Total 541.3

104

diameter soil retained percent retained percent cumulative percent passing 2 11.6 2.08558 2.0855807 97.91441927 1 13.2 2.37325 4.4588278 95.54117224

0.5 42.3 7.60518 12.064006 87.93599425 0.25 56.7 10.1942 22.258181 77.74181949

0.125 59.3 10.6616 32.919813 67.08018698 0.063 47.7 8.57605 41.495865 58.5041352

pan 325.4 58.5041 100 0 Total 556.2

Kurunn 8

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 5.2 0.88646 0.8864644 99.11353563

0.5 22.3 3.80157 4.6880327 95.31196727 0.25 36.7 6.25639 10.944426 89.0555745

0.125 49.3 8.40436 19.34879 80.65121036 0.063 47.7 8.13161 27.480395 72.5196045 pan 425.4 72.5196 100 0

Total 586.6 Kurunn 9

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 15.2 2.83265 2.83265 97.16734998

0.5 32.3 6.01938 8.8520313 91.14796869 0.25 46.7 8.70294 17.554976 82.44502423 0.125 59.3 11.0511 28.606038 71.39396198 0.063 57.7 10.7529 39.358927 60.64107343 pan 325.4 60.6411 100 0

Total 536.6 Kurunn 10

diameter soil retained percent retained percent cumulative percent passing 2 0 0 0 100 1 16.2 3.01901 3.0190086 96.98099143

0.5 35.3 6.57846 9.5974655 90.40253448 0.25 48.7 9.07566 18.673127 81.3268729

0.125 61.3 11.4238 30.096906 69.90309355 0.063 59.7 11.1256 41.222512 58.77748789 pan 315.4 58.7775 100 0

Total 536.6 Kurunn 11

105

Appendix C

Hydrometer analysis of soil:

Kabus 1

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table

2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer P

% Adjusted

Finer PA

23-Aug

4:06pm 0 25 54 55 7 0.0133 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.0133 0.0303 1.3 1.018 41.3 85.1 30.8 4:08 2 25 41 42 9.1 0.0133 0.0284 1.3 1.018 36.3 74.9 38.3 4:10 4 25 39 40 9.5 0.0133 0.0205 1.3 1.018 34.3 70.9 34.6 4:14 8 25 36 37 10 0.0133 0.0149 1.3 1.018 31.3 64.8 25.6 4:22 16 25 31 32 10.8 0.0133 0.0109 1.3 1.018 26.3 53.6 40.1 4:40 34 25 27 28 11.4 0.0133 0.0077 1.3 1.018 22.3 45.4 55.8 6:22 136 23 21 22 12.6 0.0136 0.0041 0.7 1.018 17.7 32 85.9

24-Aug

5:24pm 1518 22 15 17 13.6 0.0137 0.0013 0.4 1.018 8.4 18.1 125.4

Kabus 2

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

23-Aug 4:06pm

0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 30.1 32.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 28.9 38.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 27.9 34.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 22.8 25.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 40.6 40.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 45.4 55.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 87.1 95.9

24-Aug 5:24pm

1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 91.3 110.4

106

Kabus 3

Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table

2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer P

% Adjusted

Finer PA

23-Aug 4:06pm 0 25 54 55 7 0.0133 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.0133 0.0303 1.3 1.018 41.3 85.1 22.8 4:08 2 25 41 42 9.1 0.0133 0.0284 1.3 1.018 36.3 74.9 28.3 4:10 4 25 39 40 9.5 0.0133 0.0205 1.3 1.018 34.3 70.9 34.6 4:14 8 25 36 37 10 0.0133 0.0149 1.3 1.018 31.3 64.8 35.6 4:22 16 25 31 32 10.8 0.0133 0.0109 1.3 1.018 26.3 53.6 40.1 4:40 34 25 27 28 11.4 0.0133 0.0077 1.3 1.018 22.3 45.4 55.8 6:22 136 23 21 22 12.6 0.0136 0.0041 0.7 1.018 17.7 32 98.9

24-Aug 5:24pm 1518 22 15 17 13.6 0.0137 0.0013 0.4 1.018 8.4 18.1 110.4

Kabus 5

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

25-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 14.1 12.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 19.4 18.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 21.9 24.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 40.8 45.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 43.6 50.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 60.5 65.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 80.4 98.9

26-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 85.7 108.4

Kabus 4

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

25-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 24.1 22.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 26.9 28.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 45.9 34.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 50.8 45.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 53.6 50.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 65.4 65.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 89.8 98.9

26-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 98 111.4

107

Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted Finer PA

25-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 13.1 11.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 17.4 15.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 25.9 27.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 27.8 35.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 22.1 20.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 71.4 65.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 87.2 98.9

26-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 88.7 102.3

Kabus 8

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

27-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 5.9 11.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 4.4 8.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 11.9 17.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 6.8 12.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 5.3 10.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 2.6 5.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 64.7 78.9

28-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 73.5 98.3

Kabus 7

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

25-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 1.3 2.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 6.8 8.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 10.9 17.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 8.2 12.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 7.1 10.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 65.4 75.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 71.2 98.9

26-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 72.8 102.3

108

Kabus 9

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted Finer PA

27-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 73.1 25.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 84.4 34.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 70.9 20.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 30.8 12.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 25.6 10.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 12.4 5.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 26 12.9

28-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 17.1 8.3

Al Ufaynah 2

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg.

Ra

Hyd. Corr. For meniscus

L from Table

1

K from table

2

D mm

CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

17-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.03029 1.3 1.018 41.3 85.1 36.8 4:08 2 25 41 42 9.1 0.01326 0.02844 1.3 1.018 36.3 74.9 31.3 4:10 4 25 39 40 9.5 0.01326 0.02054 1.3 1.018 34.3 70.9 30.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 64.8 27.6 4:22 16 25 31 32 10.8 0.01326 0.01094 1.3 1.018 26.3 53.6 23.1 4:40 34 25 27 28 11.4 0.01326 0.00771 1.3 1.018 22.3 45.4 19.8 6:22 136 23 21 22 12.6 0.01356 0.00411 0.7 1.018 17.7 32 13.9

18-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 18.1 7.4

Al Ufaynah 3

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For meniscus

L from Table

1

K from

table 2

D mm

CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted Finer PA

17-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 23.2 13.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 85.1 43.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 42.6 20.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 44.8 24.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 53.6 18.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 40.4 18.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 21 10.9

18-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 78.1 37.4

109

Al Ufaynah 4

Date Time Elapsed Time (min)

Temp. °C Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

17-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 85.1 15.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 74.9 34.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 34.1 18.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 74.0 33.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 35.6 20.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 55.4 25.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 18.7 11.9

18-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 85.1 57.4

Al Ufaynah 5

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg.

Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table

2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted Finer PA

19-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 33.7 33.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 35.2 34.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 70.9 67.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 55.8 44.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 26.6 20.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 26.7 20.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 13.8 11.9

20-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 13.4 11.4

Al Ufaynah 6

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

19-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 10.7 10.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 12.4 13.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 11.3 12.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 10.2 10.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 38.4 30.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 40.1 35.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 47.3 45.9

20-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 90.4 80.4

110

Al Ufaynah 7 Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

21-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 6.4 5.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 8.9 7.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 10.9 10.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 9.8 8.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 28.5 30.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 42.4 45.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 46.8 55.9

22-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 80.1 95.4

Al Ufaynah 8

Date Time Elapsed Time (min)

Temp. °C Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table

2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

21-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 9.8 10.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 20.9 25.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 38.7 30.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 29.8 20.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 38.6 30.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 46.4 45.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 49.3 55.9

22-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 80.8 95.4

Rugut 2

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

27-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 17.1 25.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 8.4 14.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 6.9 10.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 7.8 13.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 8.2 14.1 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 35.4 50.8 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 68.4 85.9

28-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 70.8 98.3

111

Rugut 3 Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from

table 3

29-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 4:14 8 25 36 37 10 0.01326 0.0149 1.3 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7

30-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4

Rugut 4 Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3 29-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3

4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 4:14 8 25 36 37 10 0.01326 0.0149 1.3 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7

30-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4

Rugut 5

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

29-Aug 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 18.1 19.7 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 11.0 12.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 9.9 11.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 10.8 13.6 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 20.6 24.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 40.4 52.3 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 77.3 95.7

30-Aug 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 80.7 105.3

112

Rugut 6 Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

2-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 20.1 22.7 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 24.4 27.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 13.9 16.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 10.8 13.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 22.6 24.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 45.4 52.3 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 87.8 95.6

3-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 90.5 107.2

Rugut 7

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

2-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 4.1 2.7 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 18.4 17.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 14.9 13.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 20.8 18.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 28.6 26.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 26.4 24.3 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 88.5 79.6

3-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 90.7 99.3

Kurunn 1

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

4-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 13.6 14.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 15.4 16.2 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 14.9 15.4 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 21.8 22.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 34.6 36.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 45.4 64.2 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 68.1 94.8

5-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 70.8 100.4

113

Kurunn 5

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

4-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - -

4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 15.1 14.8

4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 17.4 16.2

4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 16.9 15.4

4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 24.8 22.7

4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 32.6 36.4

4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 65.4 74.2

6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 75.4 97.8

5-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 80.7 110.4

Kurunn 6

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

4-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 5.6 8.8 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 7.4 11.2 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 17.4 20.4 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 7.8 12.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 11.6 17.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 18.9 24.2 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 39.4 41.8

5-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 64.1 78.4

Kurunn 3 Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from

table 3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

2-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 3.1 2.7 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 18.4 17.3 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 14.9 13.6 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 19.8 18.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 38.6 36.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 43.4 54.3 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 73.8 89.6

3-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 87.4 108.3

114

Kurunn 7

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

4-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 10.1 9.6 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 15.4 14.2 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 20.9 18.4 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 22.8 22.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 28.6 33.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 23.4 24.2 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 82.3 81.8

5-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 88.6 98.4

Kurunn 8

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

4-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 11.5 10.6 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 16.4 15.2 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 20.9 19.4 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 22.8 22.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 33.6 34.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 23.4 25.2 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 86.2 82.8

5-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 95.3 99.4

Kurunn 9

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

4-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 10.1 12.6 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 12.4 14.2 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 16.9 18.4 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 20.8 25.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 42.6 44.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 85.4 86.2 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 92 112.3

5-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 90.1 110.4

115

Kurunn 10 Date Time Elapsed

Time (min)

Temp. °C

Actual Hydro.

Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

8-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - - 4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 10.1 11.6 4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 13.4 15.2 4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 13.9 15.4 4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 24.8 25.7 4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 29.6 37.4 4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 48.4 56.2 6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 71.2 72.3

9-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 80.1 90.4

Kurunn 11

Date Time Elapsed Time (min)

Temp. °C

Actual Hydro. Rdg. Ra

Hyd. Corr. For

meniscus

L from Table

1

K from table 2

D mm CT from table

3

a from table

4

Corr. Hyd. Rdg. RC

% Finer

P

% Adjusted

Finer PA

8-Sep 4:06pm 0 25 54 55 7 0.01326 0 1.3 1.018 - - -

4:07 1 25 46 47 8.5 0.01326 0.0303 1.3 1.018 41.3 8.1 10.6

4:08 2 25 41 42 9.1 0.01326 0.0284 1.3 1.018 36.3 12.4 13.2

4:10 4 25 39 40 9.5 0.01326 0.0205 1.3 1.018 34.3 18.9 18.4

4:14 8 25 36 37 10 0.01326 0.0149 1.3 1.018 31.3 29.8 29.7

4:22 16 25 31 32 10.8 0.01326 0.0109 1.3 1.018 26.3 28.6 27.4

4:40 34 25 27 28 11.4 0.01326 0.0077 1.3 1.018 22.3 36.4 41.2

6:22 136 23 21 22 12.6 0.01356 0.0041 0.7 1.018 17.7 78.1 84

9-Sep 5:24pm 1518 22 15 17 13.6 0.01366 0.0013 0.4 1.018 8.4 82.4 94.8

116

Appendix D

Soil texture tests Curves

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kabus 1

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kabus 2

0

20

40

60

80

100

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kabus 3

117

0

20

40

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80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kabus 4

0

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40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kabus 5

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kabus 6

118

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kabus 7

0102030405060708090

100

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kabus 8

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kabus 9

119

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Al Ufaynah 2

0102030405060708090

100

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Al Ufaynah 3

0102030405060708090

100

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Al Ufaynah 4

120

0102030405060708090

100

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Al Ufaynah 5

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Al Ufaynah 6

0

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100

120

0.001 0.01 0.1 1 10

Perc

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assi

ng

Diameter in mm

Al Ufaynah 7

121

0

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120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Al Ufaynah 8

0102030405060708090

0.1 1 10

perc

ent p

assi

ng

Diameter in mm

Rugut 1

0

20

40

60

80

100

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Rugut 2

122

0

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80

100

120

0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Rugut 3

0

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120

0.001 0.01 0.1 1 10

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ent P

assi

ng

Diameter in mm

Rugut 4

0

20

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60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Rugut 5

123

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Rugut 6

0

20

40

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80

100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Rugut 7

0

20

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60

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100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn1

124

0102030405060708090

0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 2

0

20

40

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120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 3

0102030405060708090

100

0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 4

125

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 5

0

20

40

60

80

100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 6

0

20

40

60

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100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 7

126

0

20

40

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100

120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 8

0

20

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60

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120

0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurunn 9

0

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0.001 0.01 0.1 1 10

Perc

ent P

assi

ng

Diameter in mm

Kurrun 10

127

0

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0.001 0.01 0.1 1 10

Perc

ent p

assi

ng

Diameter in mm

Kurunn 11