Flood Mitigation for Sungai Pinji, Ulu Kinta, Perak Using HEC-HMS and HEC-RAS Model

Abstract

This paper presents a simulation of flood in Sungai Pinji, Ulu Kinta, Perak using hydrologic and hydraulic model. The study utilizes two software from Hydrologic Engineering Centre: Hydrologic Modelling System (HEC-HMS) and the River Analysis System (HEC-RAS). The HEC-HMS program was used for hydrologic modelling, which involves determining rainfall-runoff relationships based on watershed characteristics, while the HEC-RAS program was used for hydraulic modelling, which involves the modelling of water level and velocity of the river. HEC-HMS was used to produce the design hydrograph, which serves as a boundary condition for the HEC-RAS hydraulic model. Two-dimensional (2D) unsteady flow was modelled using HEC-RAS, and detention pond approach was employed as the flood mitigation strategy in the simulation. In order to evaluate the accuracy and reliability of the pond approach as a flood mitigation measure, parametric study was carried out, and the obtained results were compared against the existing conditions. Overall, the computed results show that the mitigation approach is a better solution compared to the existing conditions.