Spatiotemporal variations in water conservation function of the Tibetan Plateau under climate change based on InVEST model

The Tibetan Plateau, known as the "Water Tower of Asia", is the source of many rivers in Asia, and its water conservation function is the basis for the optimization of the ecological barrier and the water security of Asian countries. Yet, the Tibetan Plateau is also an ecologically fragile area, facing numerous ecological issues and climate change risks, so the response of the water conservation function to the changing environment has received much attention. This study systematically analyzed the variation trend of the water conservation function during 1961–2017, using the InVEST model simulations, linear regression analysis, and coefficients of variation. The results show that the average annual water conservation of the Tibetan Plateau is about 256 billion m3, showing a decreasing trend from southeast to northwest, and the important areas scatter in the southeastern of the plateau, such as the lower Yarlung Zangbo watershed, the Nujiang watershed, and the Yalong watershed. The water conservation volume of the Tibetan Plateau was on the rise (P < 0.05), and there was spatial variability in the trends and coefficients of variation. The increase of precipitation and NDVI leads to the overall increase in the water conservation of the Tibetan Plateau. Our findings could be used to fill the spatiotemporal variation gaps in the water conservation function of the Tibetan Plateau.