DEVELOPMENT OF HYDROLOGICAL MODELLING USING HEC-HMS AND HEC-RAS FOR FLOOD HAZARD MAPPING AT JUNJUNG RIVER CATCHMENT

Abstract

Climate change has resulted in severe disasters such as floods, droughts, hurricanes, etc. As the climate warms, precipitation events become more frequent and intense, resulting in severe rains that may overflow rivers, streams, and drainage systems. The Junjung watershed, like many other areas, is vulnerable to floods, which may significantly damage the environment, infrastructure, and the local populace. As a result, precise knowledge of the catchment's rainfall intensity and hydrological features is required, as is the development of effective flood danger mapping. This research aims to determine the rainfall intensity for the catchment area. The study also intends to create a flood danger map for the Junjung watershed using HEC-HMS. The rainfall intensity for 50- and 100-years ARI was computed using HEC-HMS. HEC-RAS was used to produce flood hazard models, which revealed that rainfall intensity rose from the 50-years to the 100-years ARI. This indicates that the catchment is more likely to flood during extreme weather events, possibly more catastrophic flooding during uncommon, high-intensity rainfall. The Junjung watershed, according to the flood hazard mapping data, is in danger of flooding after high rains, which may result in the river overflowing and flooding the adjacent regions. As a result, reliable flood hazard maps are critical for mitigating the effect of flood occurrences in the study region.