Causes of Sedimentation Problem in Bakkhali River Estuary,Cox’s Bazar,Bangladesh

Abstract

Abstract

Sedimentation problems generally occur at locations where the sediment transporting capacity of the hydraulic system is reduced and it is most often associated with human interference in the physical system. The natural sediment load in Bakkhali estuary is comparatively higher and changes drastically. In the monsoon after a heavy rain large amount of sediment, locally called “charis”, is transported and a great amount of sand is carried through its water flash whole round the year. But the construction of the rubber dam in Bakkhali River due to the conservation of fresh water from upstream and to prevent saline water intrusion from the downstream causes the siltation in the upper region of the Bakkhali River. Again the river is getting narrower day by day due to the dumping of garbage by local people and the encroachment on both sides of the river by erecting illegal structures by land grabbers. So, these entire human interference factors restrict the normal flow velocity as well as the natural transportation of sediment load through the estuary. As a result the deposition intensity in the Bakkhali estuary decreases which may affect the process and characteristics of estuary evolution.