触发重庆山洪灾害的典型环流和影响系统分析

通过对触发重庆山洪灾害的31次区域性暴雨的特点以及产生重庆区域性暴雨的典型大气环流形势和主要影响系统的统计分析,结果表明:(1)重庆山洪灾害主要是强降水引起的滑坡、局部泥石流和小溪流的洪涝等灾害,其危害极大;(2)诱发重庆山洪灾害的典型区域性强降水主要出现在5~9月,其中7月出现频率最大;(3)绝大部分区域性强降水过程产生前,在500 hPa中、高纬地区上空形成两脊一槽型(占52%)或两槽一脊型的环流形势(占42%);(4)高原槽(高原切变)、高原涡、副热带高压、西南涡、低空急流、地面冷锋等为其主要影响系统。

Analyses on Major Effect Systems and Typical Atmospheric Circulation Triggering Mountain Torrential Disasters in Chongqing

Through the statistically analyzing the typical atmospheric circulation and major effect systems of 31 regional rainstorm cases occurred in Chongqing,the major results can be summarized as:(1) the mountain torrential disasters in Chongqing mainly come from landslides,local mud-rock flow and flood in the brooks produced by the heavy precipitation;(2) the typical local storm mainly occurs from May to September,and the most cases happen in July;(3) befor the occurrence of the most rainstorm,the patterns of two ridges with one trough(occupying 52% in the total cases) or two troughs with one ridge(occupying 42% in the total cases) are located in the high latitude;(4) plateau trough(plateau shear),plateau eddy,subtropical high,southwest eddy,low-level jet and surface cold front,et al.,are the major effect systems.