关键词: 气温, 径流, 祁连山区, 河西走廊

Abstract: Since the beginning of the past century, there is a calefacient trend for the global climate due to greenhouse gases such as CO 2 continually increasing. Especially in late 1900s the trend became obviously. On the background of global warming the air temperature in some region rises and in other some region drops. The different thermal conditions and the change of atmospheric circulation will consequentially result in the changes on distribution of precipitation and runoff. Rising of air temperature in a mountain area will reduce river flow in the same precipitation condition. Hexi Corridor Area in Gansu Province is one of the important commodity grain bases and heavy industry bases of China. Water resource is the principal factor restricting the development of society and economy in the area. Surface runoff in the Hexi Corridor area all originate from the Qilian Mountains. The temporal and spatial distributions of surface runoff as well as its amount at mountain's outlet have closely relationship with the air temperature variation in the Qilian Mountains area. So it is of the important significance to research the variation characteristics and the future trend of air temperature in the Qilian mountains area for programming, planning, developing and utilizing, and running and managing water resources in Hexi Corridor area. Based on the air temperature data since 1950s from three weather stations (the Wushaoling Station situated at the eastern section of Qilian mountain, the Qilian Station at the middle section and the Tuole Station at the western section) the air temperature sequences have been established for the three regions and for three seasons (winter: Nov. to Feb. in next year; spring: Mar. to May; and summer-autumn: June to Oct.). Analysis on the changing characters and its trend indicates that the air temperature variation in the Qilian Mountains area is in accordance with the global climate increasing in some extent, but possesses regional and seasonal differences. In details, the rising extent of winter mean air temperature is larger than that of yearly and other seasons' mean air temperature. As a whole, the variation on the mean air temperature in the Qilian Mountains area presents a discontinuously and tardily rising trend, but the rising extent is small. So it is forecasted that the variations on the mean air temperature don t possess a greater effect to the outflow from the mountains area.

Key words: air temperature, runoff, Qilian mountains area, Hexi Corridor area