Numerical Simulation: Hydro-Morphology of Meghna Estuary

Abstract

The Meghna Estuary is formed by the combined flows from three great rivers in the south-east Asia; the Ganges, the Brahmaputra and the Meghna. This estuary experiences dynamic hydro-morphological changes due to very high discharge of water and sediment from these three mighty rivers. Erosion and accretion occur simultaneously at very high rates; such that, the flow and sediment discharge through the estuary are the third highest and the highest, respectively, in the world. On the other hand, the tidal current itself is also strongly affected by the dynamic morphology changes. It is thus essential to understand the hydraulic behavior and interactive features of tides and morphology change in the estuary. With this end in view a two dimensional general model of Bay of Bengal was developed under cyclone shelter preparatory study (csps) undertaken by Bangladesh Government and the model was updated later during other projects. The present article focuses on development of model, its set-up, boundary conditions and few calibration results of this two dimensional hydrodynamic and morphology model. The model applications clearly show the variation of the flow structure; their speed and direction separately for monsoon and dry season around the model area which covers the northern part of Bay of Bengal more specifically the Meghna Estuary.