Application of Geohecras for 2D Flood Modeling of Downstream of Guddu Barrage

Abstract

Hydraulics and hydrodynamics tools, along with remote sensing data, are used for flood modeling. Flood models rely on reliable ground data for calibration and validation purposes since factors contributing to floods are complex and affect the accuracy of models. Hydrologic Engineering Center's River Analysis System (HEC-RAS) is one of the most used 1D and 2D flood modeling software. GeoHECRAS is the latest modified tool for flood modeling that uses HEC-RAS on its backend with a user-friendly interface that speeds up the process. This study used GeoHECRAS to simulate water levels downstream of the Guddu barrage on the Indus River (Pakistan). For calibration and validation of the model, water levels observed from the in-situ gauge downstream of the Guddu barrage were used. For calibrated model, the difference between simulated and observed water levels ranges from -0.1718 m to +0.1521 m. For the validated model, it was from -0.232 m to 0.138 m.