Mapping Urban Water Stress and Human-Water Conflicts: A Climate-Ecosystem Framework for Sustainable Water Management

Urban water stress is emerging as a critical challenge in rapidly developing regions where climate variability, population growth, and land-use change converge. Conventional indices largely emphasize hydrological supply or climatic drought but often neglect urban expansion, ecological resilience, and human exposure. To address this gap, we develop a Dynamic Urban–Ecosystem Water Stress Index (UEWSI) and apply it to Hunan Province, China (2000–2023) to support integrated water resources assessment and management.The framework combines net water availability (precipitation minus evapotranspiration), potential evapotranspiration, and impervious surface growth, further refined by a flood susceptibility index to establish an Urban Water Stress Classification (UWSC). Overlaying UWSC with population density enables the identification of human–water conflict hotspots, where hydrological stress and demographic concentration intersect, providing a spatial basis for prioritizing management interventions. Results indicate that water stress is primarily driven by increasing climatic demand (PET, r > 0.9), urban impervious expansion (r ≈ 0.86), and population density (r ≈ 0.85), while precipitation plays a weaker role. Eco-hydrological regime zoning through ET/PET clustering revealed stable, transitional, and stressed ecosystems, while analysis of impervious–biodiversity linkages highlights ecological trade-offs relevant for urban water conservation planning. By integrating climatic, hydrological, urban, and ecological dimensions, this study advances socio-hydrological research and delivers a decision-support framework for diagnosing stress hotspots, anticipating regime shifts, and guiding sustainable urban water resources planning and governance.