Temporal and Spatial Variation in Regional Climate and Its Impact on Runoff in Xinjiang

Under the background of global climate warming, rivers that are mainly supplied by glacial meltwater are directly impacted, especially in the arid and semi-arid areas of northwestern China, where glacial meltwater is the most important natural source for maintaining the existence and development of oases in the river basins. Consequently, hydrologic circulation processes and their response to climate change have received much attention and have become a focus of research.

Xinjiang lies in the Eurasian hinterland and belongs to the arid and semi-arid area of northwestern China. As a result of intensive disturbances due to global change and human activities, the climate of Xinjiang has been drastically transformed from a warm-dry to a warm-wet one. Therefore, analysis of the temporal-spatial variations of climate in Xinjiang and their impact on the regional surface runoff is important for sustainable utilization of water resources and ecological preservation in the region. Previous studies have focused mostly on climate change in the whole of Xinjiang or in certain regions; the variation characteristics and temporal-spatial differences in air temperature and precipitation at each station of the study area were of less concern. Accordingly, on the basis of air temperature and precipitation data from 56 meteorological stations in Xinjiang and runoff data from 8 hydrologic stations distributed in the Tarim River Basin (southern Xinjiang) and the Manas River Basin (northern Xinjiang), the present study examined the trend and period of runoff and climate factors in the study area by using nonparametric tests and wavelet analysis and investigated the temporal-spatial variation characteristics of climate factors through geostatistics.

The results indicate that the air temperature declined slightly in Kuche. There were slight increasing trends in Bayinbluk, Alar and Yutian. The rest of the meteorological stations all had significant increasing trends. The precipitation showed significant increasing trends in the Altai Mountains, Alashankou and Jinghe in northern Xinjiang and a slight decreasing trend in Tuoli. The other stations showed slight increasing trends. The annual rate of change of precipitation was greater in the northern mountain area than in the southern plains area. In the Tianshan Mountains, the decreasing trend of precipitation at Bayinbuluk was not statistically significant, while the precipitation in the other stations increased to the high-precipitation areas from two low-precipitation centers, Zhaosu and Bayinbuluk. In the Tarim Basin of southern Xinjiang, the increasing trend and increasing rate of precipitation were more significant on the northern margin than they were on the southern margin. With regard to the surface runoff, significant uptrends appeared in Kenswat, Dashankou, Shiliguilank, Xiehela and Yzmeilek. Kaqun and Wuluwat had slight increases, and Tongguzlek showed a slight downtrend. The variations in air temperature and precipitation in Xinjiang had significant periods of 4–9 years and 3–10 years, respectively. The periods for the annual runoff were 5–9 years.

This research has been published in the international journal of Water Resources Management.