2020年夏季川渝地区洪涝灾害及暴雨过程研究  

Analysis of Flood Disasters and Heavy Precipitation Events in the Sichuan-Chongqing Region in the Summer of 2020

作　　者：熊德方 孙淑清[2] 彭京备[2] 巩远发[1] XIONG Defang;SUN Shuqing;PENG Jingbei;GONG Yuanfa(Chengdu University of Information Technology,Chengdu 610225;International Center for Climate and Environment Sciences,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029)

机构地区：[1]成都信息工程大学大气科学学院,成都610225 [2]中国科学院大气物理研究所国际气候与环境科学中心,北京100029

出　　处：《大气科学》2023年第4期1007-1023,共17页Chinese Journal of Atmospheric Sciences

基　　金：中国科学院战略性先导科技专项A类XDA23090102;国家自然科学基金重点项目41630424;国家自然科学基金联合基金项目U20A2097。

摘　　要：本文针对2020年夏季川渝地区的强降水产生的洪涝过程及相应的15次暴雨过程进行了分析,并与川渝地区大旱年同期情况进行了对比。2020年夏季,西太平洋副热带高压(以下简称副高)较气候平均位置偏西、强度偏强,其西伸脊点可达110°E以西;青藏高压东伸、偏强,上下层共同作用使副高稳定维持。中纬度小波动活动频繁,使得冷空气活动往往维持在川渝上空。副高西侧气流与北方偏北风的汇合使川渝地区形成较大的水汽通量辐合区,为暴雨的发生提供十分必要的水汽条件。此外,来自印度的季风气流从印度北部至高原东侧,经由高原南侧向东输送水汽,成为另一支重要的水汽通道。2006年夏季,川渝地区为重要的干旱年,暴雨个例也最少。在这一年,副高偏东,中纬西风带短波槽不活跃,西南季风偏弱,川渝地区水汽辐合较少,这些与2020年形成了鲜明的对比。This paper investigates flooding events caused by heavy precipitation and the corresponding 15 heavy rainfall events in the Sichuan–Chongqing area in the summer of 2020 and compares them with the situation in the 2006 drought year.The western Pacific subtropical high(WPSH)was stronger than its climatological mean,and its western edge was beyond 110°E,which is to the west of its climatological position.Since the Qinghai–Tibet high was strong and extended eastward,the upper and lower layers worked together to keep the WPSH stable.The cold air that causes precipitation in the Sichuan–Chongqing region is primarily caused by short waves in the westerlies.Short waves were frequent in the midlatitudes and influenced the region.The Sichuan–Chongqing region forms an area of major water vapor flux convergence due to the joint influence of the southwesterly flows on the western flank of WPSH and the northerly wind.It provides the best water vapor conditions for the occurrence of heavy rainfall events.Furthermore,the monsoon air stream,which travels from northern India to the east side of the plateau,rounds the south side of the plateau and transports water vapor eastward,forming another important water vapor channel.2006 was a typical drought year in the Sichuan-Chongqing region,with the fewest heavy rainfall events.In contrast with 2020,the WPSH is easterly this year,the short-wave trough in mid-latitude westerlies is less active,the southwest monsoon is weaker,and water vapor convergence in the Sichuan–Chongqing region is lower.

关 键 词：川渝地区 夏季暴雨 副热带高压 水汽通量 

分 类 号：P448[天文地球—大气科学及气象学]