Spatio-temporal Distribution Characteristics of Climate Change in Qilian Mountains and Hexi Corridor

Based on climatic data of 20 stations in Qilian Mountains and Heixi corridor,methods of regression analysis and moving average were used to study the climatic changing trend of the study area,in addition,the method of Spline interpolation was also employed to research the spatial distribution characteristics of climatic change in study area.It is indicated that temperature is lower during 1960s—1980s and higher after 1990s.Trend of temperature rise is obvious and the inter-annual ratio of temperature is 0.0298 ℃ per year.The temperature rise ratio varies from 0.02 to 0.04 centigrade per year,and temperature rise in Qilian Mountains is more obvious than Hexi corridor.The regional difference in temperature rise is,with the Heihe River as the divided,characterized by the fact that it is increasing in middle-eastern while decreasing in middle-western from south to north in the study area.Precipitation is less in 1960s,whereas it is more in other periods especially after 2000.Trend of precipitation rise is weak and the inter-annual ratio is 0.6571 mm per year.The precipitation rise ratio varies from 0 to 2 mm per year,and precipitation rise in Qilian Mountains is also more obvious than Hexi corridor.Precipitation rise decreased from south to north in study area.