Temporal and Spatial Variation in Regional Climate and its Impact on Runoff in Xinjiang, China

Based on the meteorological and surface runoff data from Xinjiang for the past 50 years, this study examined the temporal-spatial variation characteristics of the air temperature, precipitation and runoff in Xinjiang using nonparametric tests and wavelet analysis. The results indicate that the air temperature declined slightly in Kuche (KC). There were slight increasing trends in Bayinbluk (BYBLK), Alar (ALR) and Yutian (YT). The rest of the meteorological stations all had significant increasing trends. The precipitation showed significant increasing trends in the Altai Mountains, Alashankou (ALSK) and Jinghe (JH) in northern Xinjiang and a slight decreasing trend in Tuoli (TL). 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 BYBLK was not statistically significant, while the precipitation in the other stations increased to the high-precipitation areas from two low-precipitation centers, Zhaosu (ZS) and BYBLK. 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 (KSWT), Dashankou (DSK), Shiliguilank (SLGLK), Xiehela (XHL) and Yzmeilek (YZMLK). Kaqun (KQ) and Wuluwat (WLWT) had slight increases, and Tongguzlek (TGZLK) 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.