Rainfall-Runoff Modelling for Kenyir Watershed using HEC-HMS Hydrologic Model

Abstract

Dam failure due to extreme runoff events can cause major impact to human lives and property. In order to protect the life and property downstream of Kenyir catchment in Malaysia, this research aimed to estimate Probable Maximum Flood (PMF) using the Hydrological Model HEC-HMS version 4.8 accompanied with the Geographic Information System (ArcGIS). The methods adopted herein includes the collection of historical meteorological data and process it using Hershfield’s statistics for generating the Probable Maximum Precipitation (PMP). Results indicate that there are very good and good matching for both of calibration and validation respectively between the predicted and observed values. whereby for calibration, NSE and PBIAS of 0.873 and -1.76% are obtained while NSE and PBIAS of 0.679 and -8.78% are obtained for validation. Moreover, the simulated reservoir pool elevations are closely correlated to the observed pool elevations during both storm events. Although slight differences are observed from the comparison, it can be concluded that the differences are considered acceptable as the general trend is similar for those simulations. Furthermore, the developed hydrologic model is reliable and applicable for the Kenyir Hydrological Watershed.