Divergent effects of temperature and precipitation on water flow into the largest lake on the Tibetan Plateau

Abstract

The majority of lakes on the TP have expanded in an accelerated manner, changing the regulation of local water cycles and ecosystems. Here, spatiotemporal changes in inflow to Selin Co (the largest lake on the TP) from 1979 to 2022 were modeled, and the impacts of warming and wetting on water volume were explored. The modeled annual mean lake inflow was 2.27 km³, accompanied by a significant growth trend of 0.035 km³/yr (p < 0.01, the contributions of warming and wetting are −0.016 and 0.048 km³/yr respectively). Warming (+0.0386 K/yr) caused a decrease of 0.33 km³ in lake inflow per year, accounting for 14.5% of the annual mean water volume, while wetting (+4.46 mm/yr) caused an increase of 0.91 km³ in lake inflow per year, accounting for 40% of the annual mean value. These divergent effects of increasing temperature and precipitation on lake inflow makes it more difficult to predict the future water resources of basins such as Selin Co.