HEC-RAS

For the flood evaluation, the HEC framework comprises the Hydrological Modelling System (HEC-HMS) and the River Analysis System (HEC-RAS) that models the hydraulics of water flow in rivers (1D) or floodplains (2D).

Staff use HEC-RAS software to perform steady backwater calculations on each stream individually, applying a uniform flow downstream boundary conditions.

HEC-RAS model input cross-sections data were collected from physical survey and extracted from DEM SRTM 90 m by using Hec-GeoRAS.

Simulation using HEC-RAS [12] shows that the discharge value is represented by PF 1 as it is shown in the legends of Figure 4 (EG PF 1, WS PF 1 and Crit PF1).

HEC-RAS software was used to assess the possible scenarios in case if any of dams was broken.

The surface flow analyses were carried out using computer software HEC-RAS to establish the location of hydraulic jump for various tail water level scenarios.

HEC-RAS, Hydrologic Engineering Center's River Analysis System (USACE 2002), was used to evaluate the impact of the channel alternatives and/or design parameters on the water surface profile before and after the implementation of each project.

The integration of the HECHMS and HEC-RAS, and WASP5 models, although not seamless, is facilitated using a relational database that links them together.