Future upstream water consumption and its impact on downstream water availability in the transboundary Indus Basin

Abstract. The densely populated plains of the lower Indus Basin largely depend on water resources originating in mountains transboundary upper Basin. Recent studies have improved our understanding this upstream–downstream linkage and impact climate change. However, use mountainous part its hydropolitical implications been ignored. This study quantifies comparative usage, through space time, downstream availability under future change socio-economic development. Future consumption relative pressure will vary greatly across seasons between various sub-basins Indus. During dry season, share surface required within is high increasing, some requirements exceed during critical winter months. In turn drives spatiotemporal hotspots to emerge where seasonal reduced by over 25 % compared natural conditions. play an important, but previously unaccounted for, compounding role steep decline per capita future, alongside population growth. Increasing may thus locally lead scarcity issues, increasingly be a driver stress season. Our quantified perspective evolving linkages highlights that long-term shared management here must account for rapid anticipate increasing competition upstream riparian states.