To better understand the variation in mountainous discharge (MD) in the future,a basin case study was conducted in the upstream Taolai River Basin (UTRB) in arid northwestern China.The Blaney-Criddle (B-C) equation,Budyko framework,and water balance method were coupled for MD calculations.The outputs of 10 global climate models(GCMs) are synthesized to confirm the future changes in air temperature and precipitation under 3 selected Representative Concentration Pathway (RCP)scenarios.The climate elasticity (CE) method was used to determine the variation in MD,and the influence of climate factors on that was quantitatively analyzed.The results reveal that the coupling framework of the three methods is suitable for MD determination in the UTRB.The weight-based synthesis of the 10 GCM outputs shows overall increases in temperature (T) and precipitation (P)under the 3 scenarios during most of the time until 2099.The above climate change leads to an increase in MD.According to CE analysis,the positive effectiveness of precipitation is greater than the negative effectiveness of temperature on MD variation,and the increase in precipitation would induce more MD in the UTRB.Uncertainty analysis reveals that GCM outputs dominate in predicting precipitation,while the RCP scenarios influence temperature more.Overall,under the background of climate change,the risk of extreme floods during wet years might increase,and a water deficit will still occur during normal and dry years.The study provides a case example for better understanding MD responses to climate change in the upper reaches of inland river basins.Findings are helpful for reasonable water resource development and utilization in the middle and lower reaches of these basins in the future.As in the Taolai River Basin,considering the future water demand across the whole basin,the development of water-saving technologies and reasonable industrial structures is crucial for a sustainable future.