Spatiotemporal variation and driving factors of water yield services on the Qingzang Plateau

Water resources are a basic need for social sustainable development and human existence.As an important national strategy for water resources security,spatial and temporal patterns and driving mechanisms of water yield ecosystem services on the Qingzang Plateau(QP)are critical for water resources management,optimal water allocation and the improvement of ecological water protection efficiency.However,only a few relevant studies are currently available.In this study,we simulated the water yield(WY)of the QP over 34 years,from 1982 to 2015,using the InVEST model and analyzed the spatiotemporal dynamic relationships between WY and climate change as well as between WY and vegetation change,using geographically weighted regression(GWR)models.The results showed that:1)from 1982 to 2015,the WY of the QP increased at an average rate of 3.8 mm/yr;2)WY presented a reduced spatial pattern from southeast to northwest;and 3)the WY driving factors have individual and spatial differences.In terms of the area percentage in promoting WY when analyzing each driving factor,precipitation(99.8%)and air pressure(53.3%)played the major roles in promoting WY,while temperature(71.9%),wind speed(57.2%),net primary productivity(87.2%),radiation(68.3%)and lake(87.7%)played negative roles.The areas where WY are dominated by temperature are the largest(41.1%),and followed by areas dominated by pressure(19.7%)and precipitation(18.5%).The results of this study provide scientific support for formulating regional water resources policy,social and economic development planning and other macro decisions for the QP.