Water-Resource Sustainability and Adaptive Management in a Cryosphere-Dependent Endorheic Basin: A Case Study of the Cherchen River, NW China

The Cherchen River Basin (CRB), a cryosphere-dependent endorheic basin in northwestern China, faces strong competition among agricultural, groundwater, and ecological water demands under pronounced seasonal runoff variability. This study integrates multi-source hydrological records, groundwater-resource assessment, sectoral water-use statistics, and groundwater-quality constraints to diagnose water-resource sustainability under 2020 reference-year conditions and develop an adaptive assessment-to-management framework. Total water supply was 471.85 million m3, of which surface water and groundwater contributed 77.3% and 22.6%, respectively. Agriculture accounted for 96.8% of socioeconomic water use, with an average irrigation application of 659 m3/mu and high-efficiency irrigation covering 41.1% of cropland. Groundwater abstraction reached 106.69 million m3, equivalent to approximately 72% of the estimated exploitable groundwater resource, indicating high groundwater dependence but not, by itself, long-term aquifer depletion. Annual gross water supply corresponded to approximately 47% of the estimated available water-resource base; because return flows were not consistently quantified, this value is treated as an annual water-resource utilization ratio rather than a formal WEI+. Benchmark calculations indicate that reducing mean irrigation application toward regional levels of 616–558 m3/mu could lower gross agricultural demand by approximately 27.8–65.4 million m3 yr−1. Based on these diagnostics, we propose a four-stage framework comprising resource diagnosis, pressure identification, management prioritization, and adaptive implementation. Management measures beyond the irrigation benchmark scenarios are presented as policy options requiring monitoring and further hydrological, ecological, or economic evaluation rather than as predetermined outcomes.