Study region: the Tarim River Basin (TRB), China

Study focus: Climate warming is rapidly retreating the cryosphere, increasing water yield variability in high mountain catchments and challenging downstream water management. A deeper understanding of water resources involving quantifying runoff components, is crucial for effective adaptation strategies in high mountain catchments. However, data scarcity limits the application of complex physically-based models in high mountain areas. To address this challenge, an enhanced conceptual hydrological model is proposed, integrating glacier and snowpack ablation processes into a classical Budyko framework-based model, using only precipitation, temperature, and potential evapotranspiration as inputs.

New hydrological insights for the region: The novel model was applied to simulate runoff and identify runoff components in the upper TRB. Results indicate that 76 % of the 25 catchments achieved good performance. From 2001–2010, observed and modelled mean annual runoff were 146.2 ± 29.2 mm/a and 143.7 ± 18.2 mm/a. We found that glacier runoff, snowmelt runoff, rainfall runoff and baseflow account for 53.8 %, 3.9 %, 12.7 % and 29.6 % of the total runoff, respectively. Furthermore, the runoff during May to September accounted for 81.4 % of the total runoff, of which glacier runoff accounted for 67.3 %. This finding underscores the importance of glacier water for agriculture irrigation in the TRB. The model provides a novel and efficient tool for runoff simulation in the glacierized basins with scarce data.