Climate Change & Impact of Sea Level Rise on Landuse Suitability

Presented by

S.H.M. FakhruddinTechnical Specialist, ADPC

fakhruddin@adpc.net

mailto:fakhruddin@adpc.net

Objectives of the study

To assess the Climate Change Impacts of Sea

Level Rise on the Land Use and Livelihood

To assess the Climate Change Impacts of Sea To assess the Climate Change Impacts of Sea

Level Rise on the Land Use and LivelihoodLevel Rise on the Land Use and Livelihood

Review of Adaptation Options Review of Adaptation Options Review of Adaptation Options

This study was conducted in 2004-05 under CEGIS, Bangladesh

Study areaDistricts:

SatkhiraKhulna Bagerhat

Thanas: 29

S u n d a r b a n s

Effects of sea level rise on the coastline of Bangladesh

Literature ReviewLiterature Review

3m

3m

1m

1m

Source: Ali, S.I. and S. Huq, 1989

The Conceptual Framework

Hazards Flooding Cyclone Salinity

Water Logging

Sea Level Rise Adaptation

Practices/ Mediating Factor

Physical Social

Economic Institutional

Land Water Suitability

Livelihoods

Land Use

Asset

Well-being

Water Resource SystemWater Resource System• Madhumati-Baleswar• Gorai-Rupsha-Pussur• Sibsha• Betna-Kobadak-Kolpetua

Base Condition

Methodology & Study Approach

Salinity Salinity SedimentationSedimentation Flooding DrainageFlooding DrainageConcentrationConcentration

Compute Changes in

Physical System Sea level rise

Scenario

Field Data

Other Studies

Evaluation of Adaptation Options

AndStrategy development

Suitability& Alternate Land Use

Review Problem Analysis

Compute Changes in

Physical System Sea level rise

Scenario

Field Data

Other Studies

Evaluation of Adaptation Options

AndStrategy development

Suitability& Alternate Land Use

Review Problem AnalysisLiterature Literature

Impacts

HydrodynamicSedimentationFlood and DrainageSalinity Intrusion Crops SuitabilityForest Suitability

Land and Water Use System

Surface Water Salinity

GW Salinity

Field and Other studies

Soil Salinity

Scenarios/Options

Models/ T

ools

Land and Water Use Suitability

Water Level

DEMLand Type

Water Level

Soil Properties

Duration

Drainage

Drainage Module

Relationship between soil map and natural drainage

Relationship between soil map and polder drainage

Soil Map

Land Type Soil Salinity

Land Type Map

DrainageMap

DEM

Inundation duration

GW

GISDrainage

Map

Scenarios

MIKE-11

Drainage Class

DEM

Criteria of Classification

GW

Compare

-Water Level-Min and Max

Min WL

Polder Area

Area ElevationCurve

Duration

Drainage Class

Drainage congestion

Pold

er W

L

Drainage Area

DEM Polder parameters

Flooding Module

HD Model

Scenarios/Options

Flood depth maps

Criteria-depth class-frequency-time

Soil map DEMDEM

Land Type

Land Type Transformation

Existing

With scenarios

Changes in Land Type

Land Type Mapping

Salinity Module

AD Model

Salinity concentration at Critical location

Crop knowledge

Field data/experience

GIS surfacing

Salinity surface/duration

GIS and Temporal data

Different scenarios

Crop Suitability Model -CROPSUIT

CROPSUIT

Suitability

LC (GIS Grid file)

SRDI soil map

Land Characteristics-LC Assumed constant in time dimension

Soil attribute database

Spatial Distribution

of LCDEM GW

Flood depth Salinity

Land Characteristics-LC Varies with SLR & adaptation option

SLR Senarios

Decision Criteria Maximum Weighted

average User defined

Suitability Matrix using Land Quality and Land

Characteristics (LQ & LC)

Adaptation options

Mathematical Model Result

Landuse Requirements

Land use type

Map Statistics/ Table

Forest health evaluation

ParametersDevelopment of

forest health evaluation criteria

and parameters

Expert

ConsultationForest cover Information

Evaluation ofForest Health Index

(Very Good, Good, Poor)

Literature Review

Flooding Salinity ConcentrationGeomorphic

featureDrainagedensity

SLR

Scenario

Adaptation

Options

ParametersDevelopment of

forest health evaluation criteria

and parameters

Expert

ConsultationForest cover Information

Evaluation ofForest Health Index

(Very Good, Good, Poor)

Literature Review

Flooding Salinity ConcentrationGeomorphic

featureDrainagedensity

SLR

Scenario

Adaptation

Options

Forest: Growth Index Modelling

Index (e.g. Sundri)Ind. Duration

Strong B B BSalinity Moderate B W G

Less G W BLow Medium High

Ind. Duration

Strong

Moderate

Less

Low Medium High

G

GG

G

B

G

B

B

B

Index (e.g. Gewa)

Present FutureSundri

Mud

f lats

(slo

pe)

High-tide water level

Low-tide water level

Rid

geso

rle v

ees

Back-swamps or basins

Mai

nr i

ver

chan

n el hoda

nol khagragolpata

keora/baen goran

Gewa

sundari

hargoza

Identify clusters based on different situation

Boro/ Boro-Rabi (Small farmer)

Bagda(Fishers)

Mixed (Wage labour)

T-Aman-Bagda

Golda

Rapidly changing/ Forest based livelihoods

T-Aman/ T-Aman/ Kharif

Physical (P)

Social (S)

Economic (E)

Very SuitableModerately SuitableNot Suitable

Relationship Building

P,S,E S SP,S P,EP,E

P,SSS S S P,S,EP,S,E P,S,E P,S,EP,S,E P,S,E S P,S,E

SuitableNot Suitable

NAPA Findings: Adaptations for Sea Level Rise

Current Adaptation Practices for Sea Level Rise Chittagong KhulnaConstruction of embankment/PolderingSalt PanningShrimp Farming(Bagda,Galda etc.)Use of pond water for household Deep tube well for drinking waterMix carfingSuggestion for future adaptation (vulnerabilities increases) Sea Level RiseLand use zoningEnsuring the normal flow of upstream waterRain Water HarvestingHill water storageIntregated wet land farmingFish culture in scientific wayCrabs rearing

Problem/issues for Climate Change Chittagong Khulna Rajshahi SylhetSalinity L HCyclone/ Tidal FloodDeforestationRainfallErosionDrainageWater shortageTemperature

Example of NAPA review

Aman area derived from multitemporal RADARSAT Standard

Beam images of 2001

Golda shrimp area using RADARSAT Fine beam images, 2000

Forest

• Sundri• Gewa• Goran• Passur• Kackra

The Topographical Distribution Elevation (m)

0.20%2.83%

10.49%

20.53%

28.79%

22.88%

10.44%

2.94%0.81%

0%

5%

10%

15%

20%

25%

30%

35%

0.0 - 0.5 0.5 - 1.0 1.0 -1.5 1.5 -2.0 2.0 - 2.5 2.5 - 3.0 3.0 -3.5 3.5 -4.0 > 4.0

Elevation (m,PWD)

DEM

Forest cover using RS

19921992 19961996

DoFDoF 1996199620012001--20032003

Evidence of Sea Level Rise in SW region

Water Level change at Hiron Point

0

0.1

0.2

0.3

0.4

0.5

1975 1979 1983 1987 1991 1995 1999 2003

Ann

ual m

ean

WL

(m, P

WD

) Rise of Water Level= 0.53 cm / year

Data used for the year : 1977 to 2000

Water level rise along Gorai-Rupsha-Passur System

y = -0.0377x + 5.7191

0

1

2

3

4

5

6

0 25 50 75 100 125 150

Distence from downstream end (Km)

Rat

e of

Wat

er le

vel r

ise

(mm

/yr)

River Systems

Figure 4.4: Downstream boundary of Pussur for different sea level rise conditions

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

24-Aug-00 26-Aug-00 28-Aug-00 30-Aug-00 01-Sep-00 03-Sep-00 05-Sep-00 07-Sep-00 09-Sep-00Time

Wat

er L

evel

(m,P

WD

)

SLR 0 cmSLR 14 cmSLR 32 cmSLR 88 cm

Hydrodynamic Model Results:• Water Levels• Discharge• Velocity• Salinity

Hydrodynamic Model Runs

D/S Boundary

U/S Boundary

Sedimentation

Bhairab_U

Kazibacha

L-Solmari

BetnaRupsa

Nabaganga

Pussur

Bhairab_U

Kazibacha

L-Solmari

BetnaRupsa

Nabaganga

Pussur

Zone of movements Change in Sedimentation rate

Flooding and Drainage

Base SLR 88 cm

Flood DepthLand class distribution under different Scenarios

27%

21%

26%

17%

8%

0%

17%

12%

26% 26%

18%

1%

7%6%

20%

29%31%

6%

0%

5%

10%

15%

20%

25%

30%

35%

Dry 0 - 30 cm 30 - 90 cm 90 - 180 cm 180 - 300 cm >300 cm

Are

a (%

)

Base SLR 32 cm SLR 88 cm

Submergence of Embankments

DrainagePolder 15

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

12:00 AM 2:24 AM 4:48 AM 7:12 AM 9:36 AM 12:00 PM 2:24 PM 4:48 PM 7:12 PM 9:36 PM 12:00 AM

Time

WL

(m+p

wd)

.

Polder WL_SLR88 cm River WL_SLR88 cm Polder WL_SLR32 cmRiver WL_SLR32 cm Polder WL_SLR00 cm River WL_SLR 00 cm

hBase = 2.19 m

hSLR32 cm = 2.1 hSLR88 cm = 1.73

TSLR88 cm = 6.5

TSLR32 cm = 6.8

TBase = 7 hrs

TSLR88 cm' = 7 hrs

TSLR32 cm' = 7.2 hrs

TBase' = 7.5 hrs

Drainage TimeTBase = 14.5 hrsTSLR32 cm = 14 hrsTSLR88 cm = 13.5 hrs

Head diffbase cond = 2.19 m 32 cm SLR = 2.1m88 cm SLR = 1.73 m

Salinity

Land use adaptationOptions: • Long term measures – Ganges barrage (OGDA option 8)• Mid term measure – Augmentation of Gorai flow (OGDA

option 7)• Construction of closures on main river systems (Pussur,

Shibsha and Kobadak rivers)• Raising embankments to prevent overtopping• Rehabilitation of drainage systems

Strategies: • Environmental: to ensure landuse as per landuse zone based on

physical suitability• Social: to maximize the social preferences, for example maximizing

paddy cultivation.• Economic: to maximize economic return through credit facilities and

other financial incentives to the farmer to grow most economically profitable crops-shrimp.

Salinity condition with adaptation

Suitability – T. Aman

Forest Suitability

Sundri

Land use Zones - Environment

Land use Zones - Environment

Land use Zones - Environment

Land use Zones - Social

Land use Zones - Social

Land use Zones - Economic

Land use Zones - Economic

Paddy Production

S u n d a r b a n s

Dominant plant distribution

Plant diversification in Sundarbans

Thank You

Courtesy to CEGIS, Bangladesh

Climate Change & Impact of Sea Level Rise on Landuse SuitabilityObjectives of the studyBase ConditionMethodology & Study ApproachCrop Suitability Model - CROPSUITForest health evaluationAman area derived from multitemporal RADARSAT Standard Beam images of 2001Golda shrimp area using RADARSAT Fine beam images, 2000ForestThe Topographical DistributionEvidence of Sea Level Rise in SW regionRiver SystemsHydrodynamic Model RunsSedimentationFlooding and DrainageFlood DepthSubmergence of EmbankmentsDrainageSalinitySalinity condition with adaptationSuitability – T. AmanForest Suitability