ON HIGH TEMPERATURE AND SEVERE DRY EVENT OF SUMMER OVER SICHUAN AND CHONGQING REGION IN LAST 50 YEARS

Based on the daily precipitation and the maximum temperature data of summer in 1961~2006 from 145 stations over Sichuan and Chongqing region,we analyzed high temperature and severe dry event.As these results show,the spatial distribution of the number of high-temperature is similar to the spatial distribution of severe dry event frequency,in addition to southwest of Chongqing region,having gradual reduction trend from west to east and high-value concentrated in central and southwest of Chongqing region and southeast of Sichuan basin;by analyzing long-term changing trend,the number of high-temperature and severe dry event frequency over most of Sichuan and Chongqing region have obvious growth trend,several stations having weak reduction trend are scattered;the number of high-temperature and severe dry event frequency over most of Sichuan and Chongqing region have experienced one interdecadal variation process;since the 21st century,on the background of global warming,the number of high-temperature and severe dry event frequency over most of Sichuan and Chongqing region have entered the most notable happening process,the growth of severe dry event on the background of the growth of high-temperature event will inevitably lead to the increase of summer drought.