Abstract:

Based on the temperature data collected from 32 weather stations in and around Three Gorges Reservoir Area,the variation trends of air temperatures in Three Gorges Reservoir Area from 1960 to 2006 were studied using the statistical methods,including linear trend analysis,accumulated variance analysis and 〖WTBX〗t〖WTBZ〗test.The results showed that:(1) On the whole,the annual mean airtemperature in Three Gorges Reservoir Area markedly had a upward trend with the warming rate of 013℃/10 a during the recent 50 years,in which there was a slightly temperature fall period from 1960’s to 1980’s and a rapidly warming after the later period of 1980’s.(2) Similar to the variations of annual mean airtemperature,the seasonal mean airtemperatures also had increasing trends,and the warming rates in spring,summer,fall and winter were 010,0005,019 and 021℃/10 a,respectively.The winter warming had the greatest contribution to the rising of annual mean airtemperature in Three Gorges Reservoir Area.(3) The jump point of annual mean airtemperature was in 1996,while the jump points of seasonal mean airtemperatures were in 1996,1993,1997 and 1996 from spring to winter,respectively.The jump point of annual mean airtemperature roughly was synchronous with that of each seasonal one.(4) The warmer year and significantly warmer year appeared after 1996 in Three Gorges Reservoir Area,and 1998 and 2006 were abnormally warmer years.The cooler years appeared before 1990’s,especially in the 1980’s,and there were no significantly cooler year and abnormally cooler year yet in the area.〖