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Bangladesh Research Site_ Dr. M Shahjahan Mondal
 

Bangladesh Research Site_ Dr. M Shahjahan Mondal

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Overview of research sites and scoping

Overview of research sites and scoping
study – Khulna, Bangladesh

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    Bangladesh Research Site_ Dr. M Shahjahan Mondal Bangladesh Research Site_ Dr. M Shahjahan Mondal Presentation Transcript

    • Overview of Study Area in Bangladesh in context of Regional and Local Settings M. Shahjahan Mondal Associate Professor Institute of Water & Flood Management Bangladesh University of Engineering & Technology Email: mshahjahanmondal@iwfm.buet.ac.bd Workshop on Water Security in Peri-Urban South Asia: Adapting to Climate Change & Urbanization 16-19 August 2010 Kathmandu, Nepal
    • GBM Basins • Bangladesh is the lower riparian of the GBM basins • 91% flows • Ganges contribution is 37% • SW part of Bangladesh is totally dependent on the Ganges water • Gorai
    • SW Bangladesh • Sundarbans – largest continuous mangrove ecosystem & a ramsar world heritage site • Mongla Port – second sea port • Khulna – third largest city • Khulna has a strong industrial base
    • Existing Problems • 28% of the population live in the coastal area • Water logging • Coastal Embankment Project (CEP) was implemented in the 1960s • A series of polders were constructed to control the intrusion of saline water • The intervention simplified the drainage network from a very large number of tidal creeks & rivers to a small number of large rivers. • This reduced the tidal volume and increased the tidal range.
    • Existing Problems • The occurrence of cyclone, storm surge and flood • The 1991 cyclone left 150 thousand people dead • Salinity in both SW & GW • Arsenic • Reduction in fresh water inflow due to u/s withdrawal & siltation • Land use change due to shrimp farming • Vulnerable to tsunami & SLR
    • Existing Problems • Coastal zone is low lying with 62% of the land below 3 m & 86% below 5 m above msl. • Due to 88 cm SLR, 11% more coastal area will be inundated • 5 ppt saline front will penetrate 40 km inland • The whole of Sundarbans will be lost • Increased salt water intrusion is considered as one of the causes of top dying of Sundari trees • Salinity level recorded near Khulna in 2007 was the highest in the past 32 years
    • Khulna City • 3rd largest city • Located on the right bank of the Bhairab-Rupsha, one of the most important distributaries of the Ganges in the Southwest Coastal Region of Bangladesh • Area: 46 km2 • Population: > 1.5 million; growth rate 5%
    • History • Declared as Pourashava in 1884 • Until partition of India in 1947, Khulna was a sleepy little district town, overshadowed by the huge metropolis of Kolkata. • After partition, Khulna began to seek its own identity. It had a sudden influx of population, which necessitated the development of a satellite town at Khalishpur under Daulatpur thana, which was about 8 km from the zero point at the Circuit House Maidan. • By 1960, the intervening space had filled out and it became a divisional headquarter. • The central location and proximity to Sundarban and seaport prompted the government to develop the jute industry in and around Khulna after the partition in 1947. • During late 1950s & 1960s, it became an important center for industrial development
    • History (con…) • Newsprint mills, shipyard, jute mills, match factories, hardboard mills were established • Khulna was given a metropolitan status in 1984 when its population exceeded one million. • But since the 1980's, the decreasing popularity of jute and jute goods in the international market, in spite of its value as a biodegradable packaging material, put a brake on further expansion of the jute industry. • But at present there are signs of a revival through new products and processes, as well as environmental compulsions. • The city is regaining impetus for growth, following the export processing activities centering on shrimp cultivation • Academic & training institutions
    • Strategic Importance of Khulna • The location of Khulna in the heart of the SW coastal region has given it many advantages. • The linkages of the city with regional towns and growth centres have made it the most important city in the region • provides links to the Mongla sea port, which is only 40 km d/s • is a major river port of the country for inland water transport • Sundarban attracts tourist from home and abroad • has a strong industrial base after Dhaka and Chittagong • This has come into focus specially after the completion of Lalon Shah Bridge and Khanjahan Ali Bridge which will facilitate Nepal and seven sister states of India to use Mongla port facilities if agreement can be made at the govt level
    • Khulna City Corporation • in 1990 with 5 thanas & 31 wards • one-fourth is city core • Densely populated; contains multi-storied buildings • The rest is a mixture of urban & peri-urban areas • There are several low- income areas and slums throughout the city
    • Urban Drainage Problem Drainage system in KCC is towards the Mayur River Drainage system is open Total length : 652 km Paved drain: 291 km Semi-paved : 56 km Earthen drain: 305 km
    • Geological & Hydrological Setting • Topographically, the city slopes towards west but regionally towards south. • The average height is 3.3 m above msl • The city lies on the Ganges deltaic plain in north and Ganges tidal plain in south and consists of late Holocene to recent Alluvium • Lithologically, the area is composed of coarse to very fine sand, silt and silty clay up to a depth of 300 m with peaty soil and calcareous as well as non-calcareous soil at the top
    • Urban Geomorphology of Khulna City LAND FORMS AND INFERRED SEDIMENTARY ENVIRONMENT AND EVENTS. NL, FB, ML and AC form peatlands in some parts of the inactive area of the Ganges delta and coastal plain. Flood plain, channels and peat lands within the Ganges delta in progradational phase with intermittent deposition of fine silt of transgrassive sea. Shallow marine shelf, estuarine and tidal flat under transgressive sea Deposits of rivers flowing in the Ganges delta during Late Pleistocene to Holocene epoch. The lower is erosive and unconformable. Tidal creeks, tidal channel and estuarine plain deposition in the coastal area in the Bengal Basin during early Quaternary epoch, which may be equivalent to upper part of the Dupi Tila Formation. The lower contact is sharp to gradational Deposition of sand in large channels in the KCC area of the southern part of the present inactive Ganges delta which may be equivalent to the Lower Dupi Tila Formation and or Upper part of the Tipam Formation. The lower contact is erosive and unconformable. Marshy area and small channels in flood plain. Note: NL= Natural Levee, FB= Flood Basin, ML= Marshy Land and AC = Abandoned Channel
    • Contemporary Water Management Issues in Khulna City • Drinking water crisis • Lowering of GWT • Poor drainage • Water logging • Water quality • Solid waste management • Climate change vulnerability • Urban planning • Dying of Mayur River
    • Drinking Water Crisis • Present water supply is mainly from groundwater sources drawn from both DTW & STW • Water supply is 13 MG per day • The coverage is only 30% of households with piped water supply • The rest is self-managed and many of the people face water crisis • To cope with this insufficient supply and increasing demand, KWASA was established in March 2008
    • Lowering of GWT During the dry season, 50% of DTWs become inoperative.
    • Poor Drainage System • Drainage system is not good – Improper slope, inadequate sections & inadequate outlets – Lack of maintenance – Disposal of wastes into drains – Encroachments & settlements on drainage paths – River and water pollution – Corruption – No study – Water insecurity in urban & peri-urban areas • There were natural drains, but widths were reduced • KWASA is responsible • KWASA needs to return back to the original drains
    • Water Logging due to Poor Drainage System In Khulna city, 38% of households regularly experience short-duration logging. In some areas, more than 90% people are affected by water logging.
    • Groundwater Quality • The aquifer system is hydraulically connected to the Bay of the Bengal & the surrounding rivers. • 85, 35 & 50% of the wells had Na+, K+ & Cl- concentrations exceeding the WHO limit. • Excess in Na+ and Cl- concentration is due to the seawater intrusion which forces the abandonment of water wells in many instances. • High TDS values in about half of the borewells may be attributed to hydraulic connection with the river.
    • Groundwater Quality of KCC area Bangladesh Parameters Average standard pH 7.87 6-8.5 EC (µs/cm) 1405.83 TDS (ppm) 1011.17 1000 Cations Na+ 209.42 200 K+ 5.58 12 Ca+ 102.50 75 Mg2+ 28.00 30-35 Cl- 292.08 150-600* CO32- 44.33 Anions HCO3- 631.92 H4SiO42- 51.17 PO43- 0.56 6 SO42- 20.92 400 Source: Shahinujjaman, 2004
    • Surface Water Quality Seasonal variation of the Bhairab Water Quality SL No. Pre Post Parameter Monsoon Monsoon Monsoon 1 pH 6.8 7.69 6.9 2 Temp (C) 31.6 28.9 22.3 4 CO2 0.15 0.15 0.2 5 DO (ppm) 7.8 6.9 6.92 6 TDS (mg) 10380 195000 6520 7 HCO3- 180 135 142 8 H4SiO4 5 2.5 2.82 9 Na+ 2300 2150 1750 10 K+ 78 72 61 11 Ca+ 96 15 84 12 Mg2+ 150 140 145 13 Cl- 4653 4330 4510 14 SO42 700 658 682 15 NO3- 3 2.8 2.9 16 PO43- 2 0.08 1.09 Khanom, 2009
    • Solid Waste Management • Solid waste generation in Khulna City is 450 tons a day. • KCC is responsible (33%) • NGOs, CBOs & private organizations are also involved (17%) • Half is collected & reaches the final disposal site which is about 8 km from the city • The uncollected waste is often dumped in an uncontrolled manner throughout the city clogging drains, blocking roads & occupying vacant plots • This causes flooding, increases traffic congestion & presents health risk
    • Climate Change Vulnerability • International Institute for Development and Environment on "Climate Change and the Urban Poor: Risk and resilience in 15 of the world's most vulnerable cities" • It identified Khulna as one of the most vulnerable cities • The report says that the major concerns for Khulna are frequent and increased level of floods, storm surges, intensity of cyclones, water logging, saline intrusion, sedimentation and river erosion. • Climate refuges in Khulna after Sidr and Aila
    • Urban Planning • KDA was created as a semi-autonomous body in 1961 • under the Ministry of Housing and Public Works • Planned development and expansion of Khulna City and its suburb areas • A new and revised master plan comprising of 451 km2 was prepared and approved by the govt in 2001 • A further expansion of the master plan extending upto the Mongla port is underway • Unlike Dhaka, Khulna is the city, which is still virgin and can be made a planned city
    • Mayur River • Derelict river • It flows to the NW side of the Khulna city • It separates Dumuria thana from the city • 9.5 km long; falls into the Rupsha River near Badamtala, Batiaghata • Subsistence uses • Few hundred fisher families • There was abundance of fish until 1983
    • Mayur River • It receives all types of municipal & industrial wastes • 18 canals & drains to drain out effluents • Slums around this river • Dumping (domestic & urban sewage, industrial effluents, agricultural wastes) at various sites of the river
    • Other Water Related Issues of KCC Tropical cyclone and storm surge Inundation of freshwater sources during cyclonic event and storm surge Increased salinity in rivers and aquifers – power plant was closed due to salinity Shortage of freshwater for agriculture
    • Other Water Related Issues of KCC Pollution of rivers and ponds from untreated urban and industrial effluents Hanging latrines on ponds and river canals Unplanned urban settlements on the river banks
    • Peri-Urban Areas in & around KCC Peri-urban areas Urban areas
    • Peri-Urban area: Identification & issues • KWASA coverage is one- third of the area • DTWs were not sunk in a planned way • KWASA is not permitting DTW installation • No DTW in Ward No. 1, 2 & 3 of Daulatpur; STW is not safe • No water infrastructure in Phultala, Batiaghata, Rupsha & Dighalia • Self managed STW/DTW • No NGO is working in WSS in peri-urban area
    • Peri-Urban area • Khals are water logged, leased out • Some are polluted • Siltation & encroachment
    • Peri-Urban area • KCC planned to lift 9 MG of GW from Phultala area with 40 DTWs • The project came to a halt in 2007 in the face of people's agitation • Madhumati water with treatment • Poddo Beel as a reservoir – farmers’ agitation • Mayur as reservoir – NGO
    • Visited area • Rupsha F. Ghat
    • Visited area • Md. Nagar • Agricultural until 2000 • Not many people • Rainfed agriculture • Land value – Tk. 3-10 thousand – Tk. 150-400 thousand • 1 DTW per 10-100 h/h • No drainage congestion
    • Visited area • 10-vent regulator at Tetultala • To prevent salt water intrusion • No coordination between BWDB & local people • Gate operation & management
    • Visited area • KWASA is looking for alternative source of water • Natural drainage is towards the Mayur River • Siltation, pollution & encroachment • Subsistence uses & use as a reservoir • ETP – cost, regulation!!! • Capacity is adequate!!! • BWDB, LGED, KCC, KDA, KWASA, DPHE, Fisheries, DC • Software!!!
    • Visited area • Sea level rise could delay discharge from the drainage system in low-lying areas • Flooding by contaminated wastewater could cause serious health risks • Changes in salinity regime from sea level rise may affect the availability of fresh surface and groundwater • Still in the process of selecting the exact field site!!!
    • Thank you
    • • At every section of an estuary, salinity varies with the state of tide and also with the up land flow. Bangladesh has a monsoonic climate. The upland river flow has a distinct seasonal pattern. The upland flow increases from June to reach the peak in August/September and decreases from October. With this variation of fresh water flow salinity varies inversely. Salinity front of a particular concentration starts moving upstreams from October and starts moving towards sea during June. • The Ocean water has salinity of 35 parts per thousand whereas in the Bay of Bengal close to Bangladesh coast it is 30–32 parts per thousand. This is due to discharge of sweet water by the three big rivers.
    • • Rajbond Trenching Ground Site: It is at present the only official dumping site, 25 acres in area situated at a distance of about 10 kms to the west of KCC Headquarter
    • Problem of Solid Waste Management On-payment door to door collection of household garbage covers about 17% households by local NGOs. 33% of the households throw waste into nearby drains, on low lands, or elsewhere.