Data collection and analysis

For all three regions of different flow regimes, time series of river discharge, water level, and suspended sediment concentration (SSC) at representative locations were collected (Figure 1). Available data were collected from governmental agencies such as Bangladesh Water Development Board (BWDB), Water Resources Planning Organization (WARPO) and non-governmental research institutes such as Institute of Water Modelling (IWM), Center for Environmental and Geographic Information Services (CEGIS), as well as reports and papers. Hourly water level data were available for all representative locations., but continuous measurements of discharge and SSC were available only for short periods of time, or at irregular time intervals. The average monthly discharge of the Gorai River at the bifurcation from the Ganges River and average monthly rainfall are presented in Figure 3. The annual hydrographs for the different flow regimes at the selected locations are shown in Figure 2. From these data, mean tidal range and average SSC during three seasons for three flow regimes were calculated.