Climatic and geo-spatial based assessment of drought susceptibility for Seraikela Kharsawan and Atreyee river basin of Dakshin Dinajpur districts of India

Abstract

The Atreyee and Punarbhaba river basins experience severe flooding which occurs frequently throughout their territory that extends into Northern West Bengal India and Bangladesh. The Subarnarekha river creates havoc destruction in the district of Saraikela Kharsawan. The region experiences monsoon season floods because of its high rainfall combined with its shallow gradients and its restricted ability to handle river water. This project aims to study flood behavior which occurs in the Atreyee and Punarbhaba river basins through hydrological and hydrodynamic modeling techniques. The HEC-HMS modeling framework conducted rainfall-runoff modeling, while the HEC-RAS 2D modeling framework performed floodplain inundation mapping through its use of high-resolution DEM and satellite-derived data. The researchers used water level and discharge data from selected gauging stations to calibrate and validate their model. The spatial analysis examined flooding which occurred at different depths and durations across Thakurgaon, Gangarampur, and Balurghat low-lying areas which showed high flooding vulnerability. The study results show that the two river basins experience significant hydrologic connections which create high flooding risk for downstream areas that depend on rainfall from upstream locations. The study establishes three core elements which organizations must implement to achieve effective and sustainable flood risk reduction: land use management and real-time hydrologic forecasting and international cooperation. The simulation results support disaster management authorities and regional planners in developing flood risk management plans which include adaptive strategies and early warning systems.