Flood Modeling and Vulnerability Assessment

Shallow water equations, which are used by HEC-RAS 2D, explain how water moves in response to gravity and friction forces in terms of depth-averaged 2D velocity and water depth. The conservation of water mass and momentum in a plane is represented by these models. The HEC-RAS finite-volume approach is characterized beneficial because of its conceptual simplicity, geometric flexibility, and conservatism. This solution enables a broader approach to unstructured mesh and approximates the average integral on a reference volume. Variability across and along the flow path can be simulated using 2D modeling with HEC-RAS. This model reveals that reframing of the bridge minimizes the flood propagation both upstream and downstream. With the increase of discharge, if we reframe the bridge width according to the river width near the crossing points, it will minimize the scouring of the bridge near River Chel and reduce the sediment accumulation upstream of River Gish and near the rail/road bridges of River Lish.