Lately extreme events have become more common along Kosasthalaiyar river’s flood plains, causing economic losses and impacting residential areas. Sediment management which includes erosion and deposition in the river bed and mouth of the river at Ennore creek is a key cause for coastal flooding during extreme events like storm surge and heavy precipitation.
Hydrological, hydraulic and sediment transport modeling are used to study and determine ways to reduce the vulnerability of flooding. The Hydrologic Engineering Centre-Hydrologic Modeling System (HEC-HMS) is used to calculate a hydrograph of heavy flows in a river drainage basin, volume of runoff and modeling sedimentation rate in the river using the Modified Universal Soil Loss Equation (MUSLE). For flood forecasting and sediment transport analysis of the Kosasthalaiyar River, the Hydrologic Engineering Centre-River Analysis System (HEC-RAS) is utilized. The study focused on three periods 2005, 2015 and 2023 based on soil profile, Land Use and Land Cover (LULC), Digital Elevation Model (DEM), precipitation and river discharge etc. HEC-HMS and HEC-RAS have shown the strong correlation in evaluating flood vulnerability and reliable forecasting.