Bangladesh Climate Vulnerability: Floods and Cyclones

BANGLADESH CENTRE FOR ADVANCED STUDIES House 10, Road 16A, Gulshan 1, Dhaka 1212, BangladeshPhone: 8818214-7, 9851234, 9852904; Fax: 9851417Website: www.bcas.net

Dr. Atiq RahmanExecutive Director: Bangladesh Centre for Advanced Studies (BCAS)Founding Chairman: Climate Action Network – South Asia (CANSA)

Visiting Professor: Fletcher School of Law and Diplomacy , Tufts University and Harvard University, Boston, MA, USA

IFPRI 2020 Conference on Building Resilience for Food and Nutrition SecurityDate: 15-17 May, 2014

Addis Ababa, Ethiopia

Outline of the presentation

1. Bangladesh: Most vulnerable country

2. Extreme Events: Climate Impacts

3. Cyclones: A Case Study

4. Floods: A Case Study

5. Responses: By Communities

CLIMATE CHANGE CASE STUDY: BANGLADESH VULNERABILITY

1. Sea Level Rise

2. Cyclone (Intensity & Frequency)

3. Deeper Penetration of Saline Water

4. Erratic Rainfall

5. Flood (Intensity & Frequency)

6. Drought

7. River Bank Erosion

8. Health

9. Food Security

10. Water Security

11. Land slide in CHT

12. Migration

Relief Map of South Asiahttp://www.flickr.com/photos/ocean_of_stars/2785428699/sizes/o/in/photostream/

Nepal

India

Myanmar

Pakistan

Bangladesh occupies a unique geographic location spanning a stretch of land between the mighty Himalayan mountain chain on the north and the open ocean on the south. It

is virtually the only drainage outlet for a vast river basin complex made up of the Ganges, Brahmaputra and the Meghna and their network.

The Complex River Systems

1. Unique geographical location2. Dominance of flood plain3. Himalayan drainage eco-system

Water Tower

Water Sink

The variability of onset, breaks and duration of the summer monsoon have enormous affects on water resources, agriculture, economics, ecosystems, and human mortality throughout South Asia and Bangladesh as well.

Location of Bangladesh in relation to major river basins in South Asia

Extreme Events: Global

Earth quakeTsunami

Volcanic Eruption

Flood & River ErosionCycloneDrought

Land slideHeat/Cold waves

Sea Level Rise and Salinity Intrusion

Nat

ural

Haz

ards

Extr

eme

Clim

atic

Eve

nts

Climate Change Related

Tectonic

Types of hazards

How Climate Change Increases Risk

Changes in the magnitude,coverage and frequency of climaticextremes

Changes in average climaticconditions and climate variability,affecting underlying risk factors

Generates new threats, which aregion may have no or littleexperience in dealing with.

10

Climatic Extreme Events

Temperature rise and heatwaves in China, Russia, Mongolia, Korea, Japan, India and South East Asia

Increased and erratic rainfall induced frequent floods in Bangladesh, India, China and South East Asia

Cyclones and Typhoons in South Asia, Bangladesh, India, Philippines, Japan and China

11

Climatic Extreme Events

Number of recorded disasters doubled globally from approximately 200 to over 400 per year in the past two decadesNine out of 10 disasters are now climate related

Sea level rise and salinity in South Asia, Bangladesh, India, Maldives, Sri Lanka, Indonesia and SEA

Droughts in South Asia including India and Bangladesh, South East Asia, China and Mongolia

Source: Swiss Re sigma Catastrophe database: Include floods, storms, droughts, forest fires, cold wave & frost, hail and other

Change in Frequency of Hazard Event

13

14

Global cost of weather extreme events is increasing to a great extent

15

Number of houses damaged per million people per year (using 21 datasets)

Source: Global Assessment Report on Disaster Risk Reduction 2011, UNISDR

16

Global Cyclones Incidence and Intensity

17

Extreme Events: Bangladesh

Hazard Class Map Ranking of multi-hazard maps used for preparing the risk-index : Cyclone ( high risk-5, risk-3,wind risk- 1) Flood (Severely flooded due to major

river floods – 3, flash flood due to major river-2, other flood-1)

Riverbank erosion(severe erosion-2, erosion -1)

Drought (very severe drought prone areas – 2, severe drought-1)

Sea

Lev

el R

ise

Cyclone

Saline Zone of Bangladesh

Err

atic

Rai

nfal

l

Flood

Flood 2004

Flood Frequency

FloodedArea

Return period (Years)2 5 10 20 25 50 100

Areaaffected %

20 30 37 43 52 60 70

Last 30years

5 3 2 2

Last 10years

3 2 1 1

Inundated Area during Different Floods and Number of Occurrences in Last 30 Years

For Example: A flood event with return period of 20 years has already occurred twice during the last 10 years.

EXISTING DROUGHT SITUATION,AND DROUGHT SITUATION IN THE YEARS 2030 & 2075

EXISTING DROUGHT

DROUGHT CLASSES (KHARIF SEASON)

Very Severe DroughtSevere DroughtModerate DroughtLess Moderate DroughtSlight Drought

Very Slight to NilSevere & ModerateModerate & Less ModerateSunderbansForest

ADDITIONAL DROUGHTPRONE AREAS IN 2030

ADDITIONAL DROUGHTPRONE AREAS IN 2075

Rive

r Ban

k E

rosio

n

Health

Source: IPCC AR4, 2007

Migration

Source: IPCC AR4, 2007

Internal initially

External later

No one wants to leave their land

Global justice: Issues of migration

Human rights: Issues of migration

Migration already happening

Strategic dimension of migration

Key Climate Change Stresses and Impacts on CHT

• Hills support sub-ecosystems which are rich in species and biodiversity

• These give livelihood supports to the hilly people

• Key stresses in CHT– Temperature rise– Erratic rainfall– Extreme events -Flood

and Landslide

Maxim

um

Temperature

Cyclones

1970

19912007

Source: DMB Situation Report,2007

• According to ICZMP coastal area includes 19 districts. Among these 16 coastal districts are considered in present study

• Total area: 42,500 km2

• Total population: 31 million (BBS, 2001)

History of major cyclones

Cyclone

Cyclones in Bangladesh

37

• Wind speed will increase around 10%for one degree Celsius increase in temperature.

• Frequency and Intensity of cyclone will be more.

Climate Change Impact on Cyclone

Recent Cyclones in the Subcontinent

SIDR: Bangladesh: 2007

NARGIS: Myanmar: 2008

RASHMI: Bangladesh: 2008

AILA : Bangladesh: 2009

MOHASEN: Bangladesh: 2013

CYCLONE

40

Floods

Frequency of Flood

42

Flood

Flood 2004

FLOOD

44

Causes

a. Heavy rainfall

b. Heavy siltation of the river bed reduces the watercarrying capacity of the rivers/stream.

c. Blockage in the drains leads to flooding of the area.

d. Landslides blocking the flow of the stream.

e. Construction of dams and reservoirs

f. In areas prone to cyclone, strong winds accompaniedby heavy down pour along with storm surge leads toflooding.

Flood

Chronology of Big Floods

Economic Loss and Fatality of Floods

RADARSAT ScanSAR Wide image, 23 July 2004

Climate Change Impact on River Flow

Sources: A study conducted by CEGIS using the hydrological model SWAT

BrahmaputraAnnual: 710,000 Mm3

Increase: 5-10%

Annual: 150,000 Mm3

Increase: 7-10%

MeghnaGanges

Annual: 350,000 Mm3

Increase: 8-17%

Climate Change Impact on River FlowCont..

• Flooding event will increase both in terms of intensity and frequency

• The average flooding depth will increase about 0.3 m

• The 50 year return period of flood event will be a 20 year event

Climate Change Impact on Flooding

The Linkage

Climate Change

Global Warming (Anthropogenic)

Temperature Rise•LST•SST

Variation in Precipitation Ice Melting and Sea Level Rise

Flood Drought Cyclone and Storm Surge

Loss of Property + Injury + Death

DISASTER

Food Security IPCC estimates that, by 2050, rice production in

Bangladesh could decline by 8 percent and wheat by 32 percent

Decrease production of livestock, Increase of pest attack Decrease production of fisheries

Development over time in Climate Change Impacted scenario and Adaptation Achievements

Dividend in climate smart development

Deve

lopme

nt ($

)

Climate impacted development loss

Climate smart adaptation benefits

Time (t) years

54

Floods and Cyclones pictures

Climate Disasters in Bangladesh

Responses: Some Examples on Community Based

Adaptation

Source: Char Livelihood Program of DFID

Raised Plinth Height

Hom

este

ad G

arde

n on

Ra

ised

Plin

th

Raised Plinth of Toilet

Livestock During Flood

Raising Plinth

Preservation of Household Assets Over False Ceiling

Storage of Food during Flood

Storage of Safe DrinkingWater & Dry Food

Community based rain water harvesting

Household based rain water harvesting

Floating Garden During Flood

Locally Known as Baira Cultivation

Raised Tube Well

Store Extra Furnace

Protecting from Erosion

Protecting Income Generating Activity

Water Collection in Hilly Region

Community People Using the Water of Re-excavated Pond

Pond Sand Filter

Household Based Rain Water Harvesting in Drought Prone Area

Drip Irrigation

Household Based Irrigation Farming

Crab Farming in Saline Water

Saline Tolerant Rice

Chickpeas in Drought Area

Seed storage system/seed bank

Adjustment in Cropping pattern Hanging Nursery

Making Soil heap

Local Adaptation Practices in Nepal

A Greenhouse in Pakistan

Examples in Agriculture

Nigeria Morocco

Senegal India

Example in Agriculture

Australia

Examples in Agriculture

Farming in Brazil

Intensive Potato Farming in Canada

Examples in Agriculture

Farming in New Zealand

Examples in Agriculture

Farming in Philippines

Examples in Agriculture