Investigation of Beijing Extreme Flooding Event on 21 July 2012
Investigation of Beijing Extreme Flooding Event on 21 July 2012
复制标题
DOI：
--
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Cma Training
中科院分区：
文献类型：
--
作者：
Cma Training
2012年7月21日，北京遭遇了1963年8月以来最严重的一次降雨过程，特大暴雨引发的洪涝灾害造成100多人死亡，财产损失超过116.4亿元人民币（约20亿美元）。根据常规的高空和地面观测、卫星和雷达资料，对这次暴雨过程进行了详细的分析和研究，主要结果如下：（1）高空槽伴随地面冷锋东移，受副热带高压阻挡，为北京地区暴雨提供了有利的天气尺度条件。(2)南海近海热带气旋的存在导致了东南向和南下的低空急流的建立和增强，为北京地区提供了充足的水汽。(3)7月20日河套涡的发展导致了该地区一个中尺度MCS的形成，其高的垂直螺旋度值使其组织良好，持续时间长。该MCS随高空槽东移，于7月21日进入华北地区（包括北京地区），并在北京地区产生了特大暴雨。(4)东南向低空急流在太行山东坡不断触发新的对流单体，并向东北方向移动进入北京地区，导致北京地区出现暴雨和特大洪涝灾害。
On 21 July 2012 Beijing experienced the most severe rainfall event since August 1963.The extreme rainfall induced flooding killed over 100 people and the property damage is over 11.64 billion RMB yuan(about 2 billion U.S.dollars).Based on the routine upper-level and surface observation,the satellite and radar data,a detailed analysis and investigation have been done on this event.The major results are as following:(1) The upper-level trough accompanied by surface cold front moving toward east blocked by the subtropical high provides favorable synoptic scale conditions for torrential rain event in Beijing area. (2) The presence of a tropical cyclone over the South China Sea near the coastline led to the establishment and enhancement of southeastward and southward low-level jet toward Beijing area,providing plenty of water vapor to Beijing area.(3) The development of Hetao vertex on 20 July led to the formation of a meso -a scale MCS over that area,and its high value of vertical helicity made it well organized and longlived. This MCS moved with the upper-level trough eastward,and was over Huabei region(including Beijing area) on the second day(21 July),producing extreme rainfall over Beijing area.(4) The south-east low-level jet constantly triggered new convective cells on the east slope of the Taihang Mountain Range,then moved to northeast direction into Beijing area,leading to the torrential rainfall and severe flooding there.