Author(s): Rocky Talchabhadel, Hajime Nakagawa, Kenji Kawaike, Nassim Sahboun
Linked Author(s): Rocky Talchabhadel
Keywords: Beel, opening size, suspended sediment, TBM, TRM
Abstract: The presence of coastal polders has aggravated the siltation problem in tide-dominated rivers and has reduced the conveyance of the rivers significantly leading to large-scale water-logging problems inside the peripheral polders. Tidal Basin Management (TBM) is the initiative to address this problem. It involves temporary de-poldering by cutting embankment in selected tidal basin. During high tides, muddy water enters into selected tidal basin and during low tides, clear water comes back eroding the riverbed. Sedimentation determines the life span of a basin and the rate of raising the land. It is essential to understand the process efficiently for sustainable operation and rotation of tidal basins. One of the key governing factors affecting the flow and sedimentation is the opening size of link canal that connects tidal basin with a river. In this research, attempts have been made to investigate the effectiveness of TBM exploring different opening sizes of link canal through laboratory experiments and numerical simulations. Four different cases with opening sizes of link canal varying from 0. 7 times river width to thrice the river width are investigated. Our finding shows even sediment carrying capacity is the function of velocity, only increasing the opening size will not allow more sediment to deposit in selected tidal basin. A natural force will tend to restore the equilibrium condition. It is recommended that the opening size equals to river width of a tidal river in tidal equilibrium works efficiently. Developed numerical model has good agreement with experimental results and can be used in a real scenario to better understand the effectiveness of the process
Year: 2017