LAUSR

Abstract Water resources are critical in semiarid Xinjiang, northwestern China, a mountainous region that heavily relies on meltwater, making it sensitive to climate change. A better understanding of climatic and hydrological changes is therefore highly required for water resources management. In this review, spatio-temporal climate change, climate extremes, snow and glacier fluctuations and variability in semiarid Xinjiang are summarized. In general terms, the available historical data demonstrate a rising mean temperature, likely increased precipitation (subject to greater uncertainty), declining snow cover and glacier extent, and increased streamflow in most rivers. Although the changes of projected future climate differ with different climate resembles, average temperature is expected to increase and seasonal precipitation will experience a slightly increase tendency. Additionally, climate extremes are predicted to become more frequent. Projected future streamflow is expected to increase although initial increase may be followed by a long-term decrease. Water demand is predicted to increase due to irrigation, population growth and economic development. We thereby conclude that water variability in semiarid Xinjiang is and will further be affected by future climate change and their hydrological impacts. However, climatic and hydrological changes differ in different basins, and the impacts of climate change on hydrological changes cannot be generalized. Historical and future climatic and hydrological changes have possible implications for vegetation and can intensify regional hydrological cycle and enhance pressure on seasonal water availability. Future research on climatic and hydrological changes in this region should reveal the mechanisms behind the change phenomenon, quantify the implications on water resources management and expand observational networks, in particular focus on snow and glacier melt processes, as meltwater is a crucial water source in this region. This research may provide suggestions for water resources management in semiarid Xinjiang and endorheic basins where totally depending on water from the surrounding mountains in central Asia or elsewhere.