Spatiotemporal Variation of Air Temperature in the Middle and Eastern Parts of the Qilian Mountains and the Nearby Regions during the Period of 1960-2014
In this study, the linear trend,correlation analysis,polynomial trend,5 year moving average,R/S analysis, Mann-Kendall test, sliding t-test and ARCGIS method were used to make a detailed analysis on the temporal variation and spatial distribution of temperature in the Qilian Mountains based on the temperature data from 19 meteorological stations in the middle and eastern parts of the Qilian Mountains and the adjacent regions during the period from 1960 to 2014. The results revealed that the multi-annual mean,maximum and minimum temperatures fluctuated with increase rates of 0.33 ℃·(10a)~(-1),0 . 27 ℃·(10a)~(-1) and 0.41 ℃·(10a)~(-1) respectively,and the temperature mutation occurred in 1991,1995 and 1990 respectively. The seasonal temperature was in an increase trend,and its increase rate reached a peak value in winter,which was mainly caused by the emission of greenhouse gases and the increase of atmospheric aerosol content. Interdecadally, the most significant temperature increase occurred in the 1990s,and the temperature increase trend was slowed down during the period of 2000-2014 compared with that during the period of 1990-1999. Such trend,however,could not considered that the global warming was stagnated because the Hurst index of temperature was between 0.5 and 1,and temperature variation trend in the future would be similiar to that in the past. Holistically, the temperature was low in the southwest but high in the east and the north. Difference of the multi-annual mean temperature variation between the north and the south was significant, the multi-annual mean temperature increase in the north was more significant than that in the south, the maximum temperature increase in the south was more obvious than that in the north,and the minimum temperature increase was similiar in both the north and south.