Maminul Haque Sarker
Accepted Abstracts: Hydrol Current Res
Knowledge on the evolution processes of rivers in the subsiding basins is limited, whereas the characteristics of the rivers in a depressed basin are found to be distinctively different from that of rivers in an alluvial floodplain. Understanding of the interaction between the processes of rivers and basins is required for long term water resources management. The metamorphosis of the rivers in a subsiding basin covering about 9,000 km2in the northeast region of Bangladesh has been studied using historical map sand time-series satellite images along with bathymetry and sediment data in order to enhance knowledge. The Brahmaputra River in Bangladesh used to flow at the southwest edge of the basin and supplied sediment to compensate subsidence. After avulsion of the Brahmaputra nearly 200 years ago to the present course of the Jamuna River, regular supply of sediment into the basin was cut down, causing net subsidence at a higher rate in the north close to a structural fault. During monsoon, the major part of the flow is transported over the basin, which makes the river morphologically inert. Sedimentation occurs in the riverbed, particularly at the river reach in the immediate downstream of the transition between the floodplain and basin floor, causing problem for navigation. This transition area is also found to be vulnerable to frequent avulsion of the river. The river becomes morphologically active again when its water is at bank or below bank level. At the initial stage of the river evolution after avulsion, the downstream reach of the river gradually diminishes as it proceeds towards and/or over the basin floor. Gradually, the river starts to build up its natural levee and becomes visible in the basin. The reach averaged width of the river on the basin floor is markedly less than that of the upstream reaches. Based on the understanding of the river, a process-response model has been developed that could be helpful to decision makers for management of land and rivers within a subsiding basin.
Maminul Haque Sarker obtained his BSc in Civil Engineering in 1980 from the Bangladesh University of Engineering and Technology (BUET) and he did his Masters in Hydraulic Engineering from IHE, Delft, The Netherlands. Later, he completed PhD from the University of Nottingham, UK. He is now working in CEGIS as the Deputy Executive Director. His main field of work is on river, estuary and delta morphology. He has many publications in journals, peer-reviewed books.
Hydrology: Current Research received 2843 citations as per Google Scholar report