Abstract

Flooding is one of the most frequent naturaldisasters in Malaysia, causing billions of ringgits in damages andnumerous deaths. One of the key strategies to lessen the impactof the disaster is by flood modelling, which is especiallybeneficial in flood risk management and decision making. Thispaper focuses on flood modelling and simulation for a riverbasin using HEC-HMS software with alternative data inputfrom rainfall data produced by weather radar (QPE). RadarQPE has the advantage of providing an areal representation ofrainfall, but it is only an indirect measurement of the values.HEC-HMS is an innovative hydrologic modeling software withthe advantage of a moderate processing time compared to themore sophisticated hydrodynamic models yet being reasonablyaccurate. The study methods include the collection andpreparation of data required, such as DEM, land use, and soiltype for study area of Klang River basin, Malaysia. Initially, thehydrologic model performed a calibration process using the raingauge data in an effort to generate the best-quality hydrologicsimulations. Subsequently, the rainfall inputs from the meangridded pixel radar QPE values were then used to rerun themodels. After model calibration, the result shows that thecoefficient of determination, R2, for the rain gauge input ishigher (0.8) compared to the radar QPE input (0.6). It isconcluded that to produce more accurate results, it wasrecommended that radar QPE calibration was necessary toenhance the data.