Abstract: Studying the impact of temperature on vegetation coverage and evapotranspiration is of great significance to cope with climate variation and maintain the healthy operation of ecosystem in arid areas. Based on the Mann-Kendall non-parametric test and the FVC inversion method, the characteristics of climate variation in Altay Prefecture, Xinjiang, China was studied to investigate the impact of this climate change on the vegetation coverage and evapotranspiration, using the temperature data from seven meteorological stations and CRU data sets for the region. The results showed as follows: (1) During the past 116 years from 1901 to 2016,the annual average temperature in Altay region was increased at the rates of  0.18 ℃·(10 a)^-1. An abrupt change of the annual mean temperature occurred in 1982 which made the accumulated change of the annual mean temperature increased by 2.2 ℃ before this year and an increase by 3.5 ℃ after it. (2) From 2000 to 2017, the vegetation coverage in Altay region showed a weak increasing trend. During the past 18 years, there were obviously peak values and the lowest value was 0.31 in 2008.In addition, before 2008,the annual fluctuation of vegetation coverage was significantly weaker than that after 2008.The change of vegetation coverage was negatively correlated with temperature in most areas of Altay, with a high proportion of 66.71%,but the proportion of positive correlation was only 18.55%,and the areas with temperature increase but a vegetation coverage reduction accounted for 31.71% of the whole area. (3) From 2000 to 2016, vegetation evapotranspiration in Altay region showed a decreasing trend in general, and there is an obvious decreasing trend from 2003 to 2008.In 2008, the lowest value is 179.16 mm. Although there has been an increase sign since 2008, the inter-annual fluctuations have been intensified. As a result, the overall vegetation evapotranspiration in Altay presents a decreasing tread from 2000 to 2016.Throughout the region, the areas with temperature decrease and ET reduction accounted for 61.65%, and a proportion of 19.92% of presented the phenomenon with temperature increase but ET reduction.

Key words: temperature variation')">">temperature variation, evapotranspiration, ecosystem, the Mann-Kendall test, Altay Prefecture