Sediment management in tidal river: A case study of East Beel Khuksia, Bangladesh

Disaster Prevention Research Institute, Kyoto University, Japan

^* Corresponding author: rocky@uh31.dpri.kyoto-u.ac.jp

Abstract

The widespread construction of coastal embankments limited the natural deposition on the floodplain and accelerated the silt deposition in river channels. It resulted in drainage congestion and large-scale waterlogging problem. The temporary de-poldering is one of the effective methods to solve this issue. During high tide, muddy water enters the selected tidal basin depositing a major portion of sediment and at low tide, relatively clearer water erodes the riverbed. This paper presents a twodimensional numerical model to simulate the mechanism of sediment transport and deposition during the process of controlled flooding. The model was applied to three different scenarios of the embankment cuts in East beel Khuksia, Bangladesh. The study recommends operating single embankment cut at a time if the tidal equilibrium is fulfilled by the opening size of that embankment cut. The developed model can be used to assess the land heightening in sediment-starved tidal basins and ultimately plan the rotation of tidal basins for sustainable sediment management.