Vegetation Greening Significantly Reduced the Capacity of Water Supply to China's South-North Water Diversion Project

Abstract. Recent global climate change and vegetation greening have important implications to Earth’s global biogeochemical cycles and climate, raising concern about the water supply of water diversion projects. To quantify how such a greening trend impacts local water balance and the capacity of water supply, we built a hybrid model based on the Coupled Carbon and Water (CCW) and Water Supply Stress Index (WaSSI) models. We conducted a case study using the Upper Han River basin (UHRB) in southern China that serves as the water source area to the middle route of the South-North Water Diversion Project (SNWDP). Significant vegetation greening occurred in the UHRB during 2001–2018, with the normalized difference vegetation index increasing at a rate of 0.5 % yr−1 (p