Climatic variability and surface water dynamics in a hilly region of northeast India: Implications for soil and water conservation in Longding district, Arunachal Pradesh

Climatic variability plays a crucial role in influencing soil moisture regimes and surface water availability in the hill ecosystems of Northeast India. This study examines the impact of long-term variations in rainfall and temperature on surface water dynamics in Longding District, Arunachal Pradesh. Multitemporal climate datasets from WorldClim for the years 1990, 2000, 2010, 2020, and 2024 were analysed to assess changes in precipitation and temperature patterns. The Normalized Difference Water Index (NDWI) was derived from satellite imagery to evaluate spatial variations in surface water distribution. Results indicate a declining trend in annual precipitation alongside a gradual rise in temperature. NDWI analysis reveals significant spatial fluctuations in surface water, reflecting the hydrological response to changing climatic conditions. Reduced rainfall and rising temperature suggest increased evapotranspiration losses, leading to stress on soil moisture retention and groundwater recharge. These changes have important implications for rainfed agriculture and watershed stability. The study underscores the need to integrate climatic analysis with remote sensing techniques for effective soil and water conservation planning in hill regions.