1. ENVIRONMENTAL MONITORING OF THESUNDARBANS: BANGLADESH PERSPECTIVE Abu Saleh Khan Deputy Executive Director IWM, Bangladesh

2. FarakkaBarrage 3. N North Central Area - 40,500 sq km North WestNorth East Population - 30 million Farakka 62% land cultivable Barrage South North Central 10% Forest, Sundarbans Centra Only remaining habitatsfor the Royal Bengal TigerSouth West South Central South WestSundarbans CAMBay ofBengal Bay of Bengal 4. Driving forces on the ecosystem REDUCED RIVER FLOW Agriculture Shrimp farming- -Manure - - - -POLDERING URBAN AREASFARMING (Groundwater)Development in the upstream catchment & freshwater flushingMicro-topographic changes due to deposit of sediments carried by rivers or tidal currentsIndustrial, maritime and agricultural pollution MONGLA PORTKNM SUNDARBANSSea level rise due to global warmingExtreme wave attack due to cyclone and tidal surges 5. Declining Ganges DistributariesSalinityTop Dying of SundarbansGroundwaterFisheriesAgricultureDesertificationChannel Siltation 6. Mathabhanga offtakeChandana nowclosed inland river Arial Khan-BuriswarJ am una Rive r Ga n ges Riv erSystem rGo iv e rai RRi hna veCh regan drMKunamapeParRUp R i ver d iv emNa b aa ganr Riga RverGorai-Passur/SibsaGorai-MadhumatiSystemBaleswar System 7. J amuna Riv erIndustrial units suffered aprogressive damage due toGa ng e sRive rCrop damage andincreased corrosion rGo ivera yield reductionaR iR ivg hn Ch er an MednKu pe r maR arPaRUpiverdmiveNa b aa rg an Ri ga Rver River water turned impotableIndustrial operation neededto carry fresh water from along distanceIncreased water borne diseasesTop-dying of Sundari trees Degradation of public health 8. Increased salinity andassociated sedimentationhas raised the river banks. Raised river banks resulted in permanent bowl-shaped depressions inside the forestRoot Zone Nuematophores are exposed to extended period of inundation resulting in top- dying of trees 9. Static water table dropped down to 23 ft(7.01m), which caused High pumping cost Saline intrusion in shallow water table Effect on surface water treatment plant Now surfaced ARSENIC pollution in groundwater 10. Arsenic59 out of 64 districts are affected 11. Fish catch reduced: Ganges by 88%Hilsha fish totally absent other rivers by 90% Beels by 31% Total loss of Tk. 4 BillionAlready some local species of fish: Sarputi, Nandai,Aeer, Belemach are no more available 12. Salinity at Khulna 20 15Salinity (ppt) 10 5 0Febraury March AprilMay DateMeasured 2000 Measured 1999 1989 1990199119921993 1994199519961997 1998 13. Water supply to G K Project drastically reducedImplementation of Mathabhanga, Baral Basin andNorth Rajshahi Irrigation Project suspended 14. Decrease in surface water enhancesDesertificationIncreased moisture deficiencydown to even wilting point andadded soil salinity result insevere damage to soil fertility 15. About 1/4 th of the countrysuffer water stress in dry season 16. When only water is diverted atupstream point with no sediment,downstream reach undergosevere morphological imbalancesand siltation occurs randomly Number of islands increased in the Ganges river from 14 to 24 between 1973 and 1996 17. Heavy SiltationModerate SiltationSlow Slitation 18. P W Hydro-Morphological Aspect1413 HardingeW a t e r L e v e l ( m Bridge 12 Monthly discharge, Jan-May reduced by 25% Monthly discharge, Jul-Sep increased by 8%1110 GK Min. WL dropped from 6.98m to 5.34m PWD Intake 9 1960s8 Post-monsoon recession reduced from 4 to 2 months76Recent5 03060 90120 150 180210 240270 300 330 360Days (from 1 April) TalbariaSelaidhaL e v e l ( m , P W D )1513Kushtia Max. WL at Talbaria11 Gorai Rail Bridge9 Bed Level at Gorai Offtake75 Min. WL at Talbaria31964 1968 1972 1976 1980 1984 198819921996 18 Feb 1997Year 19. Rainfall: 5 locationsData Collection under SBCP WL: 15 locations Salinity: 26 locations Sediment: 1400 nos. at 15 place River flow: 15 places, 1 3 rounds Water Quality: 10 parameters at 16 pl Detailed Study: at 3 pilot areas Land topography: at 3 pilot area River Sections: at 178 locations Secondary: collected from 1991 onward 20. Data collection inside the Sundarban Inundation of forestland Fall velocity measurementSiltation on forestlandRiver water level 21. Seasonal Fluctuation of Water Level East West 22. Distribution of Rainfall in the Forest Area 2002MonglaSupati Hironpoint JhaliaNotabaki 1200 1000Rainfall in mm8006004002000May JunJul AugSepOct Nov Month 23. Seasonal Salinity variation During 2002Salinity observation during 20023025201510 5 0 4/1/025/3/024/5/02 3/7/02 1/9/02 31/10/0230/12/02 DateSupatiNalianalaHiron Point Notabaki 24. Salinity Distribution inSeptember 2001 25. Salinity Distribution inMarch 2002 26. Salinity Distribution in April 2002 27. Salinity Distribution in May 2002 Non Sundari Area 28. Impact on Salinity Due to the Gorai Dredging 29. Monitoring of Water Quality Parameters Dissolved oxygen (DO) Biochemical oxygen demand (BOD) Chemical oxygen demand (COD) Ammonia as NH3-N Ammonium as NH4-N Nitrate as NO3-N Total phosphate as PO4-P Mercury (Hg) Chromium (Cr) Lead (Pb) Oil and grease 30. BOD Concentration observed during 2002 Monthly average of obseved BOD during 20022520BOD in mg/l1510 5 0JanFeb Mar Apr May Jun Jul Aug SepOct Nov Dec MonthEastern Part Western PartOne sample with erroneous result has been excluded 31. Monthly Average of Observed DO value Monthly average of observed DO (Random Sample)during 2002while profiling along channels during 2002 7.00 6.00 5.00DO in mg/l 4.00 3.00 2.00 1.00 0.00Mar Apr May JunJul Aug Sep Oct Nov DecMonthTotal Sample: 1140 Minimum Allowable Limit: 5 32. Pb Concentrations: Eastern Sundarban0.25 0.2 Harbaria HarintanaPb (mg/l)0.15 Dudmukhi Shwarankhola 0.1 Jafa0.05 Mrigamari0Jan02 Feb02 Jun02Jul02Jan03 Mar01Mar02 Oct02Apr01 Apr02Sep02 Nov01May02 Aug02Nov02 Dec02Months 33. Pb Concentrations: Western SundarbanNalianalaArpangasia BalMalancha Dingimari KaikhaliKobadak0.25 0.20.15Pb (mg/l) 0.10.050 Jul02 Jun02 Aug02 Jan02Feb02Sep02 M ay02 M ar01 M ar02 Nov01 Apr01 Apr02 Oct02Dec01Months 34. Erosion/Sedimentation of rivers inside the Sundarban 35. Patakata Khal, Chainage 0.81km40-4Level, m-8 -12 -16 -20 0 50 100150 200250 Width of the River, m Surveyed in 2000Surveyed in 1995 Erosion of river bank 36. Bhola River , Chainage 39.31km 2Level, m -1 -4 -70100 200 300400 Width of the River, mSurveyed in 2000 Surveyed in 1995Siltation on river bed 37. Selagang River, Chainage 40.67km 2-3Level, m-8 -13 -18 -23 -28 0 200 400600 8001000Width of the River, mSurveyed in 2000Surveyed in 1995 Erosion of river bed and bank 38. FLOODING IN THE SUNDARBAN 39. Inundation in Jangra Pilot Area at high and low tide 40. Inundation in Jangra Pilot Area at high and low tide 41. Inundation in Jangra Pilot Area at high and low tide 42. SALINITY VARIATION WITHUPSTREAM FRESH WATER FLOWAND SEA LEVEL RISE 43. Existing dry periodsalinity 44. Op1: Minimum 100 m3/sin Gorai River 45. OP2: Minimum 200m3/s in Gorai River 46. Op3: Minimum 200m3/s in Gorai & 50 m3/sin Kobadak, Hari, Harihar & Betna 47. Op4: 50 cm Sea level rise 48. Long profile of maximum salinity concentration along Pussur-Rupsa river system for different option scenariosMaximum Salinity in March 02 for different Options (River: Rupsa-Pussur)3025 Hiron Point Mongla20Salinity(ppt)15Khulna10 Bardia SUNDARBAN50 0 2040 60 80 100120 140160 180 200 Distance from Bardia (km )BASE op-1 op-2 op-3Op1: minimum 100 m3/s in GoraiOp2: minimum 200 m3/s in GoraiOp3: 50 m3/s in Kobadak, Hari, Harihar and Betna in addition to Op2 49. Mongla (Pussur-16.84 km) 7 6 5Salinity (kg/m 3) 4 3 208-Feb-02 10-Feb-02 12-Feb-0214-Feb-02 16-Feb-02 18-Feb-0220-Feb-02 22-Feb-02 Tim eBaseOption-1 Option-2 Option-3 Op1: minimum 100 m3/s in Gorai Op2: minimum 200 m3/s in GoraiOp3: 50 m3/s in Kobadak, Hari, Harihar and Betna in addition to Op2 50. NOTABAKI (JAMUNA_35.57)24232221 Salinity (kg/m )320191817161523-Feb-02 25-Feb-02 27-Feb-02 1-M ar-02 3-M ar-02 5-M ar-02 7-M ar-02 9-M ar-02 11-M ar-02 13-M ar-02 15-M ar-02 TimeBase op-4op-5Increase in salinity at Notabaki due to sea level rise (Op4: 50 cm SLR &Op5: 20 cm SLR) 51. Result of Hydrodynamic Model Showing the impact of Re-opening of Khorma Khal Bhola River , Chainage 39.31kmCross-section of Bhola River in 1995 and 2000 2Level, m -1 -4 -70100 200 300 400Width of the River, mSurveyed in 2000Surveyed in 1995 Proposed Bed Level Under Option Scenario 4 2BASE BED-PROFILE Note: Before drawing any0 Level(m/pwd) conclusion, this result obtained-2 from 1-D hydrodynamic model -4OPTION BED-PROFILE -6 should be verified with that of a -8sediment transport model (under-10development at present)010203040 Chainage(km) 50607080BASEOPTION-1 52. Result of Hydrodynamic Model Showing the impact of Re-opening of theKhorma KhalCOMPERISON OF DISCHARGE AT CHAINAGE 23 KM COMPARISON OF WATER LEVEL150 3.5Change in Flow Volume3 Change in Water Level100 2.5 WATER LEVEL (m.PWD) 50 2DISCHARGE (M 3/S) base Q23km 1.50 Option Q23km 1 -50 0.5-100 0 -0.5 16/9/01 17/9/01 18/9/01 19/9/01 20/9/01 21/9/01 22/9/01 23/9/01 24/9/01 25/9/01 26/9/01-150 0:00 0:000:000:000:000:000:000:000:000:000:0016/9/01 17/9/01 18/9/01 19/9/01 20/9/01 21/9/01 22/9/01 23/9/01 24/9/0125/9/01 26/9/010:00 0:000:000:000:000:000:000:000:00 0:000:00 TIMETIMECOMPARISON OF VELOCITYBase Option 1.5 Change in Flow Velocity1 Note: Before drawing any 0.5conclusion, this resultVelocity(m/s)0obtained from 1-D -0.5 hydrodynamic model should -1 be verified with that of a -1.5sediment transport model) 16/9/01 0:00 18/9/01 0:00 20/9/01 0:00Time22/9/01 0:00 24/9/01 0:0026/9/01 0:0 53. [meter] Water Quality Modelling495000.0490000.0485000.0480000.0475000.0470000.0465000.0460000.0455000.0450000.0445000.0DO mg/l440000.0435000.0430000.0425000.0420000.0415000.0410000.0405000.0400000.0 380000.0 400000.0 420000.0 440000.0 460000.0 480000.0 500000.0 520000.0 [meter] Modelled DO level on 17-8-2001 03:00 (Monsoon) in the Forest area 54. [meter] Water Quality Modelling495000.0490000.0485000.0480000.0475000.0470000.0465000.0460000.0455000.0450000.0445000.0DO mg/l440000.0435000.0430000.0425000.0420000.0415000.0410000.0405000.0400000.0 380000.0 400000.0 420000.0 440000.0 460000.0 480000.0 500000.0 520000.0 [meter]Modelled DO level on 09-12-2001 19:00 (Post-monsoon) for the Forest area 55. [meter] Water Quality Modelling495000.0490000.0485000.0480000.0475000.0470000.0465000.0460000.0455000.0450000.0445000.0DO mg/l440000.0435000.0430000.0425000.0420000.0415000.0410000.0405000.0400000.0 380000.0 400000.0 420000.0 440000.0 460000.0 480000.0 500000.0 520000.0 [meter] Modelled DO level on 28-6-2001 01:00 (Dry) for the Forest area 56. SWIMSSundarban Water Information ManagementSystem 57. Achievement at a glanceComprehensive data collection on water level, salinity,sediment, discharge and water quality Introduction of hydrological data collection on the forestlandImprovement of Hydrodynamic and AD Model Introduction of non-point load assessment and Development of Water Quality Model (indicative)Application of HD & AD model for development of differentoption scenariosDevelopment of SWIMS database and incorporation ofavailable data and maps prepared 58. Unfinished Tasks of SBCP Inundation/siltation study on forest land at more areas Improvement of HD model incorporating additional channels/creeks andupdated x-sections Improvement of Salinity & WQ model to simulate scenarios with more confidence Development of Cohesive Sediment Transport Model to study sedimentation process Establishment of Bench Mark at Southern Boundary Stations Exploring possibility of increasing flow in the western river system- Ganges Barrage Option 59. Thank You