Impact of Landuse Change on The Inundations in The Ciberes Watershed

Abstract

Whenever the rainy season approaches, the Ciberes River always inundates a number of regions. This research was conducted to determine the effect of land use change on the inundation in the Ciberes Watershed, given the aforementioned context. Using land cover change data from 2000 to 2023, a hydrological and hydrodynamic analysis of the Ciberes Watershed is conducted to determine the impact of landuse change. This investigation employs HEC-HMS for hydrological modeling and HEC-RAS for 1D and 2D hydrodynamic modeling. The simulation results demonstrate that the change in CN value is directly proportional to the flood discharge, and the flood discharge is directly proportional to the height of the flood inundation. Based on these findings, it can be concluded that the river’s cross section can accommodate flood discharges with a return period of 50 years, except in coastal areas. whereas the floods that occurred in 2018 and 2022 have a 10-year return period. It can be concluded that the topographical condition of the river in the downstream segment, which has a higher elevation than the surrounding land and flat soil conditions, is the primary cause of inundation in the Ciberes Watershed.