“070812”云南元江特大山洪泥石流气象成因分析

Meteorological causes of heavy mountain flood debris flow on Aug.12,2007 in Yuanjiang County of Yunnan Province

利用MICAPS常规资料、加密自动站雨量、FY-2C卫星TBB资料和多普勒雷达探测等资料,分析了云南元江2007年8月12日特大山洪泥石流灾害的气象成因。结果表明:低层冷锋切变在南移过程中受"帕布"台风低压外围较强东北气流的阻挡和引导,使切变转向后在哀牢山附近形成与山脉平行的西北东南向风向切变是造成本次降雨过程的主要天气系统,切变线附近形成的中尺度系统和多普勒径向速度的逆风区产生的短时大暴雨,是引发元江"8.12"特大山洪泥石流灾害的直接天气原因。

By use of the MICAPS conventional and intensive auto-station rainfalls observation data and FY-2 satellite TBB products and Doppler radar＇s data,the synoptic cause of great mountain flood debris flow on Aug 12,2007 in Yunjiang County of Yunnan was analyzed.Results indicate that the stronger northeast outer-ring air current is obstructed and led by low pressure of Typhoon＂Pabuk＂,so that the shear shift formed in southeast direction near Ailao Mountain is the main synoptic system causing this rainfall process.The formation of a mesocale system near the shear line and the short-time heavy rain caused in Doppler radar dead-wind area are the direct reasons leading to heavy mountain flood debris flow occurring in Yujiang County on Aug 12,2007.