Exploring Hydrological Processes and Land Management Impacts in the Hamp River Basin—A SWAT Model Approach

Rainfall‑runoff modeling is a critical component of hydrological studies, aiding in analyzing river basin responses to climatic variations. This paper examines the rainfall‑runoff behaviour of the Hamp River Basin, part of the Mahanadi River System, using the Soil andWater Assessment Tool (SWAT). SWAT, a physically based, continuous‑time model, predicts land management effects on water, sediment and agricultural yields in large watersheds. This study calibrates and validates SWAT for the Hamp River Basin to assess its effectiveness in simulating stream flow. Additionally, it explores the implications of land management policies on hydrological processes, examining policy‑model interactions to understand regulatory impacts on runoff and sediment yield. Simulated policy scenarios predict hydrological changes under different land management strategies. By integrating socio‑economic characteristics, the study analyses hydrological changes affecting local communities, particularly regarding land use and agricultural sustainability. Soil conservation strategies are evaluated to recommend measures for mitigating sediment loss and enhancing resource conservation. The Hamp River watershed, within the Seonath sub‑basin of the upper Mahanadi basin, was studied to estimate sediment yield and nutrient loss. Critical agricultural sub‑watersheds and associated Hydrological Response Units (HRUs) were identified using ArcSWAT. The area was divided into 16 sub‑watersheds based on topographical features from a Digital Elevation Model (DEM) and drainage networks. Land cover, soil and DEM data were used to create HRUs, enabling annual runoff analysis across calibration and validation periods (2017–2023).