Drought and flood risk assessment under the IPCC risk framework in an agriculturally dominated tropical river basin, India

Abstract

Climate change increases the severity and frequency of water-related hazards in tropical areas, posing significant risks to agriculture as well as the livelihoods of rural communities. The present work advocates an integrated approach to climate-induced risk assessment of agricultural systems in the tropical river basin, specifically the Shilabati River, India. In this work, risk maps were developed using the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) framework by integrating hazard, exposure, and vulnerability indices derived from 34 physiographic, climatic, hydrological, edaphic, and socio-economic indicators. The Random Forest (RF) model was employed to predict flood and drought risk across the study area, while RF-based Mean Decrease Gini analysis identified maximum temperature, relative humidity, drought intensity, soil moisture, elevation, population density, land use, Topographic Wetness Index (TWI), proximity to rivers, and lithology as the most influential factors. The results indicate that 17.64% (407 km²) of the agricultural land is flood-prone, affecting approximately 3.63 lakh people, while 27.02% (623 km²) is drought-prone, impacting about 4.56 lakh people. Overall, 45% of the basin falls within the high agricultural risk category, highlighting the acute vulnerability of small and marginal farmers to climate-induced flood and drought hazards. By integrating multiple hazards (i.e., floods and drought) within a unified framework, this research advances beyond previous approaches on single-hazard studies and provides actionable insights for climate-resilient agricultural planning. The findings directly support the United Nations Sustainable Development Goals (SDG 1 : No Poverty, SDG 2 : Zero Hunger, SDG 13 : Climate Action) by informing targeted adaptation strategies, strengthening food security, and promoting sustainable rural development in hazard-prone areas of the basin.