Work

Spatial heterogeneity and drivers of surface-groundwater interactions in the Yarlung River Watershed during the peak meltwater season under climate warming

Year: 2026

Type: article

Abstract: Study region This research was conducted in the Yarlung River watershed (YRW) on the southeastern Tibetan Plateau (TP), a representative alpine cold region catchment. Study focus The focus of this study is to investigate the spatial heterogeneity of surface-groundwater (SW–GW) interactions and their driving environmental factors in this alpine basin. An integrated approach combining field investigations, physical measurements, and radon isotope (²²²Rn) tracing was employed to quantify groundwater contributions (GC)—the proportion of groundwater relative to surface runoff, and to elucidate key interaction patterns controlled by geomorphology, sediment composition, and climatic forcing. New hydrological insights The results demonstrate significant spatial heterogeneity in SW-GW interactions along the river's main stem: (1) Groundwater discharge is limited in the upstream reaches, (2) Intensive SW-GW exchange occurs in the midstream, and (3) Discharge is subsequently reduced in the downstream. Additionally, climate warming-induced changes in permafrost and vegetation cover are exerting an increasing influence on hydrological connectivity, particularly in the middle and lower reaches. The observed hydrological patterns, with minimal anthropogenic disturbance, provide a natural baseline for understanding SW-GW interactions under evolving climatic conditions. This study underscores that combining field data with isotopic process-based modeling is crucial for identifying dominant controls on SW-GW interactions in alpine regions. The findings enhance the understanding of cryosphere-hydrosphere linkages and offer a scientific basis for water resource assessment in vulnerable alpine basins.

Source: Journal of Hydrology Regional Studies

DOI: 10.1016/j.ejrh.2026.103529