Spatio-temporal Change of Temperature during 1957-2007 in East Gansu,China

The spatio-temporal characteristics of the surface air temperature change in East Gansu during 1957-2007 are quantitatively studied based on monthly and daily mean temperature data from 1957 through 2007 of 15 meteorological stations and its combination with methods of GIS spatial analysis techniques and mathematical statistical theory.Mainly affected by landforms,the regions with high mean annual air temperature are in the center of East Gansu,and regions with low mean annual air temperature are at western regions.Consistent with the temperature change trend in China and even the world,the annual mean surface air temperature in East Gansu shows a generally increasing trend,especial obviously in spring and winter.The principal period of annual mean temperature variation is 13-year,and those of seasonal variations are 25-year,25-year,13-year,and 7-year respectively in spring,summer,autumn,and winter.The abrupt change of annual mean temperature occurred in the mid-1980s,and those of seasonal mean temperature began in the mid-1990s,early 1990s,late 1980s and early 1990s,respectively.