Land use dynamics and hydro-climatic variability to hydrological responses in Tawa River Basin, central India

Quantifying hydrological responses of river basins to combined hydro-climatic variability and land use/land cover (LULC) change (1999–2019) is fundamental to sustainable water resource management in regions experiencing intensifying anthropogenic pressures. This study investigates how climatic variability and land-use dynamics drive hydrological change in the Tawa River Basin, a strategically important tributary of the Narmada River in central India, whose hydrological behaviour underpins regional agricultural productivity, ecosystem functioning, and water supply security. The primary objective is to detect, attribute, and quantify shifts in surface runoff generation, streamflow variability, and water balance partitioning driven by interacting climatic and land-use forcing. Long-term hydro-climatic data were analysed using ordinary least squares regression, coefficient of variation, standardized anomaly, Mann–Kendall trend detection, and Sen’s slope estimation. Basin rainfall exhibits moderate inter-annual variability (CV ≈ 19.7%) with a slight increasing trend, implying potential augmentation of surface runoff and flood frequency. Temperature displays a consistent warming trend of 0.012 °C per year (≈0.24 °C per decade), with persistently positive anomalies characterising the post-2009 period signalling increased evapotranspiration demand, reduced base flow, and altered seasonal streamflow regimes. Concurrently, LULC transitions particularly expansion of agricultural and built-up areas at the expense of natural vegetation have reduced infiltration capacity and amplified direct runoff response. An attribution framework disaggregated observed hydrological change into climatically driven and land-use-driven components, demonstrating that both exert significant and distinguishable influences on the basin’s hydrological regime. These findings carry direct implications for reservoir inflow estimation, flood risk assessment, and long-term water resource planning across the Narmada sub-basin system.