Abstract:

The arid region of Northwest China is a special natural unit, which responds sensitively to the global climate change. Studies on the impact of climate change on water resources in the arid region of Northwest China have a significant effect on the adaptability of future climate change. Based on the latest research results, this paper analyzes the impacts of climate change on the formation and transformation of water resources and water cycle in the arid region of Northwest China. The results can be shown as follows: (1) The air temperature and precipitation in the arid region of Northwest China had a significant increasing trend in the past 50 years, however, the sharp increasing trend has retarded since the 21st century. (2) The temperature change in winter could be the most important factor for the unusually sharp rise in annual air temperature in this region. Moreover, the Siberian High and carbon dioxide emissions could be the most important reasons for the higher rate of the winter temperature rise. (3) Pan evaporation in the region exhibited an obvious decreasing trend until the early 1990s (1993), however, the downward trend reversed to go upward since 1993. The negative effects of warming and increasing evaporation on ecology have been highlighted in the arid region of Northwest China. (4) The glacier change has exerted great impact on water resources and its annual distribution in the arid region of Northwest China, and many rivers have passed the "Glacier inflexion". In the Tarim River Basin, the proportion of glacier melt water to runoff is high (e.g., as much as 50%) and it is supposed that the runoff may show a great fluctuation in the near future. Global warming not only increases the frequency and intensity of hydrological extremes, but also intensifies the fluctuation and uncertainty of inland rivers.

Key words: climate change, water resources, arid region of Northwest China