近50年来川渝地区夏季高温及严重干燥事件分析

利用川渝地区1961~2006年145个台站夏季的逐日降水和最高气温资料，分析了该地区夏季高温和严重干燥事件的时空演变特征，结果表明：川渝地区夏季高温日数与严重干燥事件的空间分布比较相似，除重庆东南部以外，基本呈自西向东阶梯状递增趋势，高值中心集中在重庆中部、西南部以及四川省东南部；从长期变化趋势来看，川渝地区大部夏季高温日数与严重干燥事件的发生频次以增长趋势为主，呈减少趋势的若干站点分布较零散，且减少趋势不显著；除小片区域以外，川渝地区大部夏季高温日数和严重干燥事件发生频次经历了“1960s〖FY（〗增〖FY）〗1970s〖FY（〗减〖FY）〗1980s〖FY（〗增〖FY）〗1990 s〖FY（〗增〖FY）〗2000～2006”的年代际变化过程；21世纪以来，在全球气候变暖的大背景下，川渝地区大部无论是夏季高温还是严重干燥事件都进入了近50年来最显著的高发期，气温和降水特征变化所造成的干旱压力大增，必然导致夏季旱灾发生几率的增大

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.〖