Impact of climate change on the long-term water balance in the Yarlung Zangbo basin

The Himalayan and Tibetan Plateau (TP) region serves as the “Asian water tower”. Yarlung Zangbo basin (YZB) is one of most important major rivers originating from TP sustaining billions lives in downstream alluvial plain. Climate change has impacted hydrological cycle this alpine region; however, temporal spatial trends runoff balance not been quantified adequately. Here, we have optimized snowmelt module Soil Water Assessment Tool (SWAT) for YZB to quantify historical future variability runoff, water, components. According results Coupled Model Intercomparison Project Five Six (CMIP5 CMIP6) precipitation (2020–2099) projected by CMIP6 will increase 2.7% when compared reference (1980–2019), while 10.2% CMIP5. average air temperature (2.4°C) exceeds that CMIP5 (1.9°C). between 2020 2050 decrease −12.7% with reference, it further decline −9.2% during 2060 2099. Based on CMIP6, deficit primarily due an evaporation 42.4%, whereas (−32.1%), yield (−9.4%), soil (−19.8%), groundwater recharge (−17.8%) decrease. Long-term evaluation implicates middle upper reaches face a higher risk drought, implying potential threat sustainability grassland ecosystems upstream.