WelcomeWelcome toto thethe PresentationPresentation onon NecessityNecessity ofof WaterWater--relatedrelated disasterdisaster managementmanagement inin BangladeshBangladesh ByBy Md.Md. AbdulAbdul HyeHye Executive Engineer & Chief Staff Officer Bangladesh Water Development Board 01 December 2007 1 GeoGeo--PhysicalPhysical SettingSetting BangladeshBangladesh Bangladesh Myanmar 2 BangladeshBangladesh atat aa glanceglance [[WaterWater Sector]Sector] Total area : 1,47,570 sq.km. Arable land: 82,400 sq.km.(8.24 Million ha) Population: 145 Million (approx.) Population density: 950 persons/ sq. km. Poverty level: 49.8% (as per BBS/WB). Total food production: 46.17 Million Mt. Ground Elevation (in PWD): 0-5m – 30% 5-30m – 45% >30m – 25% 3 A riverine country with Cherapunji (in INDIA) 310 rivers Worlds highest rainfall 4600 1 4200 5 0 0 26 • Total river length : 24,000 km 00 1 9 1 0 7 0 0 2 0 2 • Trans-boundary rivers : 00 2 0 0 57 nos. - 54 from India and 0 2 1 0 2 0 2 8 - 3 from Myanmar 0 9 0 0 River erosion 0 - Annual land loss: 10,000 ha. - Annual displacement of population: 64,000. - Annual accretion in the Meghna estuary: 1,880 ha. 4 Ganges,Ganges, BrahmaputraBrahmaputra && MeghnaMeghna BasinBasin AreaArea India N Brahmaputra Catchment epa l Bhutan Ganges Catchment Meghna Catchment Bangladeshevsjv‡`k Catchment of main three rivers is 1.72 million sq. km, of which only 7% lies within Bangladesh 5 Main Features of Major Rivers of Bangladesh Brahmaputra Ganges Meghna Length of River (km) 2,900 2,550 900 Length within Bangladesh (km) 270 (9.3%) 260 400 (10.2%) (44.44%) Total Basin Area (km2) 552,000 1,087,001 82,000 Basin Area within Bangladesh (km2) 39,100 (7%) 46,300 35,000 (4%) (43%) Highest Recorded Discharge (m3/s) 98,300 76,000 19,800 Lowest Recorded Discharge (m3/s) 2,860 (2.9%) 261 Tidal (0.34%) (---) Annual Sediment Transport (Mton) 600 286 ¾ Annual River flows 1200 BCM ¾ Annual Sediment flows 1.8-2.0 Billion Tons ¾ Stored over Bangladesh floodplain ¾ Stored over Bangladesh floodplain would would have about 9.0 m water depth have about 1.60 m thick sedimentation 6 Integrated Water Resources Management (IWRM) Integrated Water Resources Management (IWRM) is a well coordinated and participatory approach of a multi-functional system of water, man, land and related resources, to ensure a sustainable utilization of the water resources and an equitable distribution of its benefits, which optimally contribute to the social and economic development of the society; without compromising the sustainability of the vital eco- system. 7 Integrated Water Resources Management The most important elements of Water Resources Management, that need to be integrated are: • Efforts of man • Water quality and quantities • Technical, environmental and social issues • Land and water use • River basin, estuary and coastal zone • Legal frame work • Community based national and international water management and cooperation 8 Key Challenges of Water Resources Management in the 21st Century ¾ Meet demand for human system ¾ Protect Nature and nurture the natural system ¾ Political will. ¾ Uncertainty on availability of Water and sensitivities of Trans boundary River issues. ¾ Sustainable development ¾ Professional need ¾ communication skills ¾ in-depth knowledge of policy, finance and public involvement 9 NaturalNatural Disasters/VulnerabilitiesDisasters/Vulnerabilities • Flood - Flood occurs in Bangladesh regularly. - 1954, ’55, ’74, ’87, ’88, ’98,’04 & 07 floods were catastrophic. Drought - About 25% of the country suffer water stress in dry season. • River erosion - About 10,000 ha agricultural land erodes every year. - Bank erosion ranges from 250-800 m every year. • Sedimentation - Loss of navigability. 10 NaturalNatural Disasters/VulnerabilitiesDisasters/Vulnerabilities (cont(cont’’d..)d..) • Salinity intrusion - Severe environmental degradation in SW areas. • Arsenic contamination - 59 district out of 64 are affected. • Desertification - Reduction of dry season flow induces creeping desertification in the Ganges dependent area. • Cyclonic surge - Annual phenomenon, however cyclone 1970, 1991 & 2007 were catastrophic. • Climate change - 1.5 m sea level rise would affect 15% of the total population & 16% of the land area. 11 DisastersDisasters inin BangladeshBangladesh 12 Flood FloodFlood occursoccurs inin BangladeshBangladesh regularlyregularly BeingBeing lowlow--lyinglying country,country, averageaverage 22%22% areaarea isis floodedflooded everyevery yearyear InIn casecase ofof severesevere flood,flood, 66%66% areaarea inundatedinundated 1954,1954,’’55,55,’’74,74,’’87,87, ’’ 88,88,’’98,98, 20042004 && 20072007 floodsfloods werewere catastrophiccatastrophic 13 CausesCauses ofof FloodsFloods UniqueUnique GeographicalGeographical LocationLocation ExcessiveExcessive runrun--offoff fromfrom upstreamupstream LowLow topographytopography RiverRiver siltationsiltation SeaSea swellswell duringduring monsoonmonsoon HydraulicHydraulic CharacteristicsCharacteristics ––lowlow gradientsgradients ofof majormajor riversrivers Ganges: 4 cm/km, B.Putra: 8 cm/km, Meghna: 3 cm/km 14 FloodFlood ManagementManagement StructuralStructural NonNon--structuralstructural 15 StructuralStructural BuildingBuilding EmbankmentsEmbankments DifferentDifferent HydraulicHydraulic StructuresStructures ReservoirsReservoirs DamsDams GroynesGroynes SpursSpurs 16 NonNon--structuralstructural FloodFlood ForecastingForecasting && WarningWarning ErosionErosion PredictionPrediction EnvironmentalEnvironmental MonitoringMonitoring WatershedWatershed ManagementManagement PlanningPlanning && DevelopmentDevelopment PolicyPolicy 17 R e a l Present Flood Forecasting T i m Rainfall & Warning System by BWDB e D a t a Indian Data WMO Internet JRC River stage WARPO Dissemination Telemetry/Data box/Voice to the public wireless communication Radio BMD Weather forecast Synoptic charts Modem Telephone Television SPARRSO Dissemination Sattelite images Boundary estimation Fax Modem to various agencies Rainfal, 24, 48, 72 hr Fax Water level forecasts water level Bulletine manual entry via modem flood extent maps FFWC Radio Tower Data Entry & Processing Modelling & Mapping thana inundation maps GIS data layers FFWC Satellite dish 18 RiverRiver ErosionErosion RiverRiver erosionerosion isis anan inevitableinevitable naturalnatural phenomenonphenomenon andand causescauses humanhuman sufferingssufferings 70,00070,000 haha lostlost inin Jamuna/BrahammaputraJamuna/Brahammaputra onlyonly (1970(1970--1998)1998) SevereSevere cutcut inin livingliving standardstandard LossLoss ofof life,life, valuablevaluable assets,assets, crops,crops, livelihoodlivelihood DisplacedDisplaced toto citycity slumsslums && unendingunending miserymisery DisplacedDisplaced asas highhigh asas 2424 timestimes inin lifelife spanspan RiverRiver coursecourse stabilizationstabilization isis neededneeded forfor floodflood mitigationmitigation andand effectiveeffective developmentdevelopment 19 RiverRiver BankBank ErosionErosion 20 River Bank Protection Project along the R/B of Brahmmaputra-Jamuna River Sirajgonj Hard Point Revetment Length : 2550 m Cost : 332.57 crore Cost per meter length:1.30million/meter 21 Contribution of BWDB through River Bank Protection Work (Since inception) Value of Type of protection workwork Expenditure assets Facilities Facilities Groynes/ Revetment (Tk. in protected Crore) Spurs (Nos) (km) (Tk. in Crore) River bank protection 220 468 3,784 40,000 work About 30 district Head quarters , 70 upazila Head quarters and 100 commercial installations are fully or partly protected through the aforesaid works. 22 DroughtDrought…… To minimize drought effect, no measures have yet to be followed while Bangladesh faced significant loss in the last few years. – The most drought prone area in Bangladesh is north western region. – Even in irrigated areas sometimes drought occurs because of improper irrigation scheduling. 23 Drought About 25% of the country suffer water stress in dry season 24 RiverRiver SedimentationSedimentation 1.81.8 toto 2.02.0 billionbillion tonstons ofof sedimentsediment areare carriedcarried byby thethe threethree riverriver systemssystems annuallyannually SedimentationSedimentation isis veryvery acuteacute inin thethe riverriver systemsystem inin thethe southsouth westwest region,region, becausebecause ofof decreasedecrease inin dischargedischarge inin thethe GangesGanges duringduring lowlow flowflow SedimentationSedimentation isis alsoalso acuteacute inin thethe majormajor distributariesdistributaries 25 Adverse Impact of Intervention in the Upper Catchment due to Farakka barrage in India. Ganges under Hardinge bridge • Ecological disaster • Decrease in agricultural production • Desertification • Tremendous reduction of dry season flows • Heavy Siltation • Intrusion of saline front (about 80 km) • Disruption in navigation • Reduction of induced groundwater recharges • Decrease in Lively hood • Significant area will be silted up • Mass Migration • Increased soil salinity 26 Siltation in Ganges Dependent Area and increase of water salinity i.e. expansion of areas being affected by salinity Overall biodiversity including the production of Agriculture, Fisheries and industries, navigation and the production of wood in Sundarbans have been seriously deteriorated. 27 Arsenic Contamination of Groundwater 59 districts out of 64 are affected 28 Salinity Intrusion Industrial units r e v Crop Damage and i suffered a una R m a G J ang Yield Reduction e s R progressive ive r G r o