Spatiotemporal heterogeneity of hydrochemistry and runoff composition, and their responses to environmental elements in the Alpine inland river basins of Central Asia

Abstract

Study region: The alpine inland basins of Central Asia (AICA), China Study focus: We obtained hydrochemical and stable isotope monitoring data for multi-water type samples (including river water, shallow groundwater, glacial meltwater, snow meltwater, and precipitation) over three years to systematically explore the regional spatiotemporal heterogeneity of hydrochemistry and the runoff composition in the AICA and their responses to environmental elements. New hydrological insights for the region: (1) Significant spatiotemporal heterogeneity of total dissolved solids (TDS), ions, and δ18O values was observed in different water samples, especially in river water samples. (2) The annual average contributions of shallow groundwater, precipitation, and glacier/snow meltwater to regional runoff in the AICA were 49.6 %±9.3 %, 32.6 %±11.8 %, and 17.8 %±7.4 %, respectively. (3) Spatial heterogeneity in the inland river runoff composition pattern was observed in the AICA, particularly in spring. (4) The Shiyang River was found to have a potential drinking water safety risk, while oasis agriculture in the Aksu River basin should be limited. Regional environmental fluctuations posed new challenges for the simulation and estimation of regional inland river runoff. The results of this study provide a substantial background for planning the sustainable utilization of regional water resources.

Keywords

• Hydrochemistry
• Stable isotope
• Runoff composition
• Inland rivers