2019年长江中下游伏秋连旱演变特征  

Evolution Characteristics of Continuous Drought in Late Summer and Autumn in the Middle and Lower Reaches of Yangtze River Valley in 2019

作　　者：李俊[1] 袁媛[2] 王遵娅[2] 赵伟[1] 元慧慧[1] 郁红弟[1] LI Jun;YUAN Yuan;WANG Zunya;ZHAO Wei;YUAN Huihui;YU Hongdi(Unit 31010 of PLA,Beijing 100081;National Climate Centre,Beijing 100081)

机构地区：[1]中国人民解放军31010部队,北京100081 [2]国家气候中心,北京100081

出　　处：《气象》2020年第12期1641-1650,共10页Meteorological Monthly

基　　金：国家基金委-云南省政府联合基金(U1902209);国家自然科学基金项目(41776039)共同资助。

摘　　要：2019年7月下旬至秋季,长江中下游地区发生了近50年来历史同期最严重的伏秋连旱,并给多地农业、生态、水资源等带来了严重不利影响。利用我国逐日台站气温和降水资料以及全国逐日气象干旱综合指数,详细分析了2019年长江中下游7省(湖北、湖南、安徽、江西、江苏、浙江、福建)伏秋连旱的主要特征,并将干旱发展演变过程与近10年最严重的2011年春旱做了简要对比。分析表明,2019年7月下旬至秋季(7月20日至11月30日),长江中下游区域平均降水量为近50年历史同期最少,平均无降水日数和平均气温分别为1961年以来历史同期第二和第一。该区域持续高温少雨,导致气象干旱迅速发展,重旱以上平均和最大面积均达到1961年以来历史同期最大,使其成为近50年来历史同期最严重的伏秋连旱。此次气象干旱表现出以下显著的特征:干旱范围广、强度大;始于黄淮而止于江南,旱灾旱情最重位于江南地区,且持续时间最长;东西振荡和南北摆动幅度大;各阶段干旱平均强度和持续时间呈现大致反位相的波动特征。In the late summer and autumn of 2019,the most severe meteorological drought struck the middle and lower reaches of the Yangtze River Valley(MLRYRV)in the past 50 years,bringing serious adverse effects on agriculture,ecology and water resources in seven provinces located in the MLRYRV.Using datasets of daily temperature and precipitation at stations in China and daily meteorological drought composite index,this paper analyzed the main characteristics of this severe drought in the seven provinces(Hubei,Hunan,Anhui,Jiangxi,Jiangsu,Zhejiang and Fujian)in 2019.The spatio-temporal evolution of the drought was also briefly compared with the spring drought in 2011,which was the most serious drought in spring of recent decade.The analysis showed that from late July to autumn in 2019(from 20 July to 30 November),the regional average precipitation was the lowest in the same period of recent 50 years,and the average dry days and the average temperature were respectively the second most and the highest during the same period since 1961.The continuous high temperature and few rainfall in this area led to the rapid development of meteorological drought.The average and maximum area above the severe drought level have reached the largest in the same period of history since 1961,making it the most seriously continuous drought in late summer and autumn during the past 50 years.The significant characteristics of this severe drought are as follows:the drought had a wide range of influence and great intensity;the drought started from the lower reach of Yellow River and Huai River and terminated in the regions south of the Yangtze River Valley,where it persisted for a very long time and caused the most serious drought disaster;the drought vibrated from east to west and oscillated from north to south in longitudes and latitudes,respectively;and its averaged intensity and duration in each stage showed a wave characteristic with roughly reversed phase.

关 键 词：长江中下游 干旱 降水量 气温 气象干旱综合指数 

分 类 号：P466[天文地球—大气科学及气象学]