The coastal belt in the southwestern Bangladesh is facing a unique problem compared to other part... more The coastal belt in the southwestern Bangladesh is facing a unique problem compared to other parts of the country because of the direct interaction of the saline surface water (SW) from the coastal rivers and nearby sea with the fresh groundwater (GW) in the underlying aquifers. In this study, an integrated river-aquifer model is developed for the shallow unconfined aquifer in the southwestern Bangladesh to simulate the GW flow characteristics and dynamic flow exchanges between the rivers and aquifer systems. Well-known USGS numerical code for GW flow simulation, MODFLOW and its river simulation package (RIV) are applied in the framework of GW Modeling System (GMS) software, which is satisfactorily calibrated against the observed water levels. Simulation result demonstrates that fluctuations of hydraulic heads are dependent on seasonal variations of recharge from precipitation and riverbed leakage. In addition, the river-aquifer relationships proved to be very responsive to water table fluctuations, which indicate the losing or gaining characteristics of the river reaches. This form of dynamic interactions in an integrated river-aquifer system is important in the field contaminant hydrology, which greatly influence the overall system. The study finally concludes that the developed integrated river-aquifer model opens a window for better understanding of a coupled SW-GW system and thereby finding the potential causes of shallow GW pollution by the contaminated recharge water particularly in the coastal area of southwestern Bangladesh.
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Papers by Tanmay Chaki