Levee Breach using HEC-RAS 2D Model

Abstract

Floods are one of the most catastrophic natural hazards in the world affecting human adversely and causing some irreparable damages and resulting in loss of human lives. Flood effects the urban population more in terms of disasters. It is impossible to rule out natural calamity but with analyzing the floods properly, mitigating measures and tools can be used to reduce the damages. There are numerous techniques available to produce flood hazard maps and flood zoning maps because of flood simulations based on 1D, 2D ,3D or 1D-2D models. In this research, the datasets of HEC-RAS have been used to model coupled 1D-2D for White River, Muncie, Indiana. The river reach is modeled as 1D, and the adjacent floodplains separated by raised levee are modeled as 2D and both 1D and 2D are coupled through lateral connections. The objective of this study was to explore the potential of 1D-2D models in simulating the levee. The potentials and limitations of HEC-RAS 2D have been explored and coupled models are simulated for levee breach and levee overtopping floods and flood inundation floods generated as results are presented. The change in grid sizes, computational timesteps and Manning value ‘n’ have also been incorporated to observe the output of the model.