Climate Change and Water Management in Bangladesh · International Conference on Global Climate...

International Conference on Global Climate Change and its Effects Dhaka, August 25, 2008

Climate Change and Water Management in Bangladesh

Ainun Nishat Ph.D.

Country Representative, Bangladesh, andCoordinator, Climate Change Program, Asia Region

IUCN, the International Union for Conservation of Nature


The world’s water resources

Oceans 97.5%

Glaciers, Snow & permafrost 1.725%

Ground water 0.075%

Lakes, swamps & rivers 0.025%

Ref: From the presentation of David Grey, Sr. Water AdvisorClaudia Sadoff, Lead Economist, The World Bank


Growing water scarcity(1995-2025)

SEI - Criticality index (Source: WaterGAP)


Is Climate Change real …..?• IPCC TAR 2001: The Earth’s Climate system has demonstrably changed

on both global and regional scales since the pre-industrial era. The IPCC-FAR(2007), confirms unequivocally that Climate change is due to increase in concentration of GHGs.

• Stern Review ( 2007) : ‘poorest countries and people will suffer earliest and most’. Lord Stern (May 2008) called for up to 90% reduction in GHGsbelow 1990 level by 2020.

• Carbon dioxide concentrations, globally averaged surface temperature, and sea level are projected to increase under all IPCC emissionsscenarios during the 21st Century. CO2 emission has increased from 280 ppm before industrial revolution to about 380 ppm now. It may reach 800+ ppm by end of this century.

• Climate change and climate variability are now real and a stable situation is not likely to be achieved soon.


Some Definitions……

Climate Change: any change in climate over time.Climate Variability: variations in the mean state and other statistics (such as occurrence of extremes,etc.) of the climate on all temporal and spatial scales. Adaptation is a process to cope with the changing environment.Mitigation is interventions to reduce the sources or enhance the sinks of greenhouse gases.


Projected rise in surface temperature

Source: IPCC 2001Source:IPCC2001


Global Warming

Sea Level Rise

Snow Cover

SPM (IPCC, 2007)


What is likely to happen

Frequency of extreme climatic events will increaseIntensity of extreme climatic events will increaseOccurrence of erratic and unusual behaviour of weather will be frequent Sea Level will rise; to what level is being debated.


The globally averaged surface temperature is projected to increase by 1.4 to 5.8 ºC over the period 1990 to 2100. Scientists worry as they can not predict as to what will happen if it goes above 2 ºC.

Global mean sea level is projected to rise by 0.09 to 0.88 m between the years 1990 and 2100.

Globally averaged annual precipitation is projected to increase during the 21st Century.

Glaciers and ice caps are projected to continue their widespread retreat during the 21st Century. Dry season flows of river will shrink in future.

Likely Impacts


Dry seasons will have less rainfall. There will be an increase in irrigation water demand unless offset by diversification with dry-foot crops.There will be erratic behavior of weather.Forests will be affected as climate changes and plants will need time to adjust.Flora and fauna and their inter-relationship will be in jeopardy. Many species will disappear, many will face problems in surviving.Drought tolerant, saline tolerant and submergence tolerant varieties of crops will be required to cope.

Likely Impacts…..


Likely Impacts ……

Vulnerability to both flood and drought will increase.River flooding may increase in duration. Flash flooding will be more frequent. Short duration rainfalls may create drainage congestions specially in urban areas.A sea level rise of 0.5m by 2050 will cause low lying coastal areas to go under water. Small island states may disappear. It will also exacerbate drainage congestion in the coastal plains.Frequency of tropical cyclones will increase. Storm surge depths will increase.


IPCC-III scenario for Bangladesh


Comparison of Yearly Mean Temperature

-1.0

-0 .8

-0 .6

-0 .4

-0 .2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Year

Dev

iatio

n (°

C)

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

Year

Dev

iatio

n (°

C)

-0.4

-0.3

-0.2-0.1

0.0

0.1

0.2

0.30.4

0.5

0.6

1951

1953

1955

1957

1959

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

Year

Dev

iatio

n (°

C)

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1951

1953

1955

1957

1959

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

Year

Dev

iatio

n (°

C)Global

Bangladesh

Northern Hemisphere

Dhaka

Source: BMD 2007


Temperature Trend in Maijdee Court

The regression equation shows that annual average temperature has an increasing tendency and has increased by 0.86ºC from 1952 to 2001

Trend of Annual Average TemperatureMaijdee Court

y = 0.0176x - 9.2354R2 = 0.2771

24.00

24.50

25.00

25.50

26.00

26.50

27.00

27.50

1940 1950 1960 1970 1980 1990 2000 2010

Years

Ann

ual A

vera

ge T

empe

ratu

re

AnnualTavgLinear (AnnualTavg)

Source: IUCN 2007


Temperature and Precipitation Trend

25

26

27

28

29

30

31

32

33

34

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Months

Max

imum

Tem

pera

ture

( o C

)

1990 1991-19951996-2000 2001-2005

Monthly maximum temperature Monthly average rainfall

050

100150200250300350400450500550600650700750800

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Months

Prec

ipita

tion

(mm

)

1990 1991-19951996-2000 2001-2005D

roug

ht

Wat

er lo

ggin

g

Source: IUCN 2007


Rainfall Trends, Noakhali

595422Standard deviationIncrease in variability

31712979Annual rain (mm)1979-031952 -79Period

9237Standard deviationIncrease in variability

194183Avg 1 day max rain (mm)1979-031952 -79Period

According to local people occurrences of Deep depressions and Cyclonic disturbances are more frequent with higher intensity

Source: IUCN 2007


Crop calendar and water regime of Bangladesh

J F M A M J J A S O N D

Surface Water

Ground Water

Aman(monsoonrice)Aus(premonsoonrice)Boro(dry seasonrice)Robi/Wheat

Monsoon Rain

SuplimentaryIrrigationIrrigation

Premonsoon Flood

Monsoon Flood

Postmonsoon Flood


Flood Inundation Depth Map Existing Condition

Land Level (m PWD)

Inundation Depth (m)

7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.150.15- 0.300.30- 0.600.60- 0.900.90- 1.801.80- 3.60Above 3.60

No Sea Level Rise Upstream flow: Average Year (Year 2000 flow)

Source: CEGIS 2006


Land Level (m PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.150.15- 0.300.30- 0.600.60- 0.900.90- 1.801.80- 3.60Above 3.60

Upstream flow: Average Year (Year 2000 flow)

Flood Inundation Depth Map: Projection Year 2015Sea Level Rise 10 cm


Land Level (m PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.150.15- 0.300.30- 0.600.60- 0.900.90- 1.801.80- 3.60Above 3.60





Land Level (m) PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.150.15- 0.300.30- 0.600.60- 0.900.90- 1.801.80- 3.60Above 3.60



Land Level (m PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.150.15- 0.300.30- 0.600.60- 0.900.90- 1.801.80- 3.60Above 3.60




Pathways of Climate Vulnerability & Impacts

River flowTemp'r rise Glac ial melt

Trade

Food productionand security

Economic andlivelihood impacts

Speciesmigration

Biodiversity

Wet paddy culture Fossil fuel use

Ec onomic andlivelihood changes

Climate c hange

Cyclones and s tormsurges

Salinity ingress incoastal zones

Pathogens and vectorborne diseases

Human and animalhealth

Human habitationpatterns

Agric and land usechanges

Industry and infr changesInundation andbeach eriosion

Sea level rise

Carbon enrichedatmosphere

Drought and heavyrains

Flooding

Temperatureextremes

Thermal exp'n ofwater

Polar icemelting

Temperature rise

Rainfall runoff changes

Natural and anthropogenic attmosphericconcentration of GHG


Projected impacts of climate change

1°C 2°C 5°C4°C3°C

Sea level risethreatens major cities

Falling crop yields in many areas, particularly developing regions

FoodFood

WaterWater

EcosystemsEcosystems

Risk of Abrupt and Risk of Abrupt and Major Irreversible Major Irreversible ChangesChanges

Global temperature change (relative to pre-industrial)0°C

Falling yields in many developed regions

Rising number of species face extinction

Increasing risk of dangerous feedbacks and abrupt, large-scale shifts in the climate system

Significant fall in water availability e.g. Mediterranean and Southern Africa

Small mountain glaciersdisappear – melt-water supplies threatened in several areas

Extensive Damage to Coral Reefs

Extreme Extreme Weather Weather EventsEvents

Rising intensity of storms, forest fires, droughts, flooding, heat waves

Possible rising yields in some high latitude regions

Source: stern review


Vulnerabilities

Energy-+-++-+++

Human Settlement++++++++----

Health-++-+++++++++++

Biodiversity-++++++++++++++

Industries-+++++-+++++++

Infrastructure+++++++--+++

Livestock-+++++++++++++

Fisheries-++++++++++

Crop Agriculture-+++++++++++++++++++

Salinity Intrusion

Coastal Inundation

FlashFlood

River Flood

SectoralVulnerability Context

ErosionCyclone and

Storm Surges

FloodDroughtSea Level RiseExtreme Tempera

ture

Physical Vulnerability Context

Source : NAPA 2005


Probable adverse impacts

Hydro-meteorological events

• Increase in annual rainfall

• Increase in droughts • Occurrence of short

duration heavy rainfall• Rainfall at unexpected

time• Rise in temperature• Increase in

cyclones/typhoon/hurricanes

Other Impacts• Sea level rise

– Increase in salinity in coastal belt

– Inundation of coastal plains

• Increase in river erosion• Increase in coastal

erosion• Increase in vector borne

disease


Options for AdaptationFLOOD MANAGEMENT• Flood management

– Dams and reservoirs– flood management infrastructure– dykes/embankment/ polder/ levee/bund– sluices, – pump stations, – flood Evacuation shelters

• Evacuation • Shelter management

• Flood forecasting system – Lead time,– Language – Dissemination

Drought Management• Barrages• Irrigation facilities, pump stations, tube wells.


Options for Adaptation………Storm surge and Cyclone/Typhoon/ Hurricane• Coastal dykes/embankment/ polder/levee• Coastal aforestation• Cyclone Shelters

– Evacuation– Shelter management

• Cyclone forecasts and Warning– Lead time,– Language – Dissemination

Erosion control measures• River trainingCapacity enhancement for Disaster Management• Capacity of local level institutions• GO-NGO relationship


Tools and methodologies for analysis

• Statistical analyses based on probability functions on basis of past observed data (preferably of 30 years) is used by engineers and professionals to plan and design irrigation projects, flood management infrastructures, drainage systems ( also bridges/ culverts) etc. Modification to this approach will be required.

• Results from GCMs/ Climate Models, developed at regional or country level, that will project future conditions will be required to ‘climate proof’ all infrastructures and decide upon design parameters.


• Target year– 2012 – to match with Kyoto protocol ?– 2015 – to match with MDG Targets ?– 2030, 2050, 2100 to match with IPCC

projections. • Short term, Mid Term and Long term

scenarios may be developed;• But information and data from upstream

regions are essential for such planning.

Planning horizons


Bali Action Plan and Bangladesh

• Bangladesh’s submission to UNFCCC Secretariat on Bali Action Plan:– Food security,– Water Security,– Security for Livelihood,– Energy Security,


Water and Climate Change:IPCC technical Paper IV, June 2008

• Hydrologic Cycle changed– Increase in water vapour– Changes in precipitation pattern

• Intensity and extremes• Melting of ice and snow cover• Changes in soil moisture and runoff

• Increase in risk of flooding and drought• Increase in stream flow as snow melts; then in the

long run flow will decrease.• Current water management practices not robust

enough,


INDICATORS OF CLIMATE VARIABILITY AS IDENTIFIED BY STAKEHOLDERS

Excessive rainfall at times, untimely and irregular heavy rain,

Increase in tidal bores, increase in number of cyclonic conditions, variation in tidal flow

Increase in frequency of flash flood,

Temperature variation, change of seasonal cycle, cloudy and cold winter,

increase in droughts and dry spells,

Storms and hailstorms,

Increased surface temperature,

Intensity of mist/fog increased in the winter.


Concluding Remarks• We must prepare for Adaptation to Climate

Variability (the already occurring extreme events) and keep in mind the trend indicated in Climate Change forecasts. Time is now to act on Adaptation.

• But being located in the lowest part of the three major river basins, our preparation is constrained by cooperation and coordination with all upper riparian.


Thank YouThank You

Climate Change and Water Management in Bangladesh · International Conference on Global Climate...

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