Peak Discharge Determination using HEC-HMS for Flood Analysis: A Case of San Simon, Pampanga

Abstract

In order to address problems regarding flooding, modeling is now widely recognized as an effective tool for dealing with the complex dynamics, large-scale, and unpredictability of water resource systems. Hydrological modeling, in particular, is a frequently used method for estimating a basin's hydrological response to precipitation. This study was conducted in San Simon, Pampanga. It is one of the flood-prone areas in the province of Pampanga. It is a town that sits along the Pampanga River basin. This study was able to determine the peak discharges of the subbasins enclosed by the boundary of San Simon. This study utilized the QGIS software to delineate each subbasin as well as HEC-HMS software to generate the discharge hydrograph and determine the peak discharges of each subbasin based on design storm with 2-, 5-, 10-, 15-, 20-, 25-, 50- and 100-year return period. Moreover, the maximum capacity of the subbasins were computed manually and were compared to the simulated peak discharges to determine if there is flooding or not. The highest peak discharge for all elements was calculated for the 100-year return period design storm while the lowest was calculated on the 2-year return period. Some parts were already flooded in Subbasin 6 by the design storm with a 10-year return period. For the succeeding year return periods, namely 10-, 15-, 20-, 25-, 50- and 100-year return periods, selected stations from Subbasin, 4,5 and 6 were all flooded. The simulation of peak discharge data generated in this study can be utilized for flood management. Moreover, the data generated from this study can also be used to lower the danger of flooding through hydraulic modeling and mapping the flood inundation zones.