西双版纳近50年暴雨气候特征分析

Heavy rains in the past 50 years in Xishuangbanna Climate Analysis

利用1961～2007年云南省西双版纳州降水观测资料,统计分析西双版纳暴雨时空分布特征,进一步揭示其活动规律及主要影响因素.结果表明:西双版纳暴雨具有明显的季节和地域分布特征,91.8%的暴雨出现在雨季5～10月,70%的暴雨为局地性单站暴雨,69.7%的暴雨天气伴有雷击或大风、冰雹、飑线等强对流天气,东南部出现暴雨和大暴雨的次数明显多于西北部.影响西双版纳的暴雨天气系统,大致可分为两高辐合、切变、热带系统、南支低槽、副高外围和500hPa低涡6种类型,其中中低层的水汽通量辐合区,低层辐合、高层辐散的散度场,正涡度区以及垂直速度上升运动区都与暴雨区有较好的对应关系.

Use from 1961 to 2007 in Yunnan Xishuangbanna precipitation data,Statistical analysis of spatial and temporal distribution characteristics of heavy rains in Xishuangbanna,Further reveal the law of its activities and the major influencing factors. The results showed that:Xishuangbanna seasonal rain have obvious characteristics and geographical distribution,91.8% of the rain appears in the May-October rainy season,70% of the rain for the Board to heavy rains of a single station,69.7% of the heavy rain accompanied by lightning or high winds,hail,squall lines,severe convective weather,Heavy rain occurred on the south-east and the frequency of heavy rain much more than the north-west. The impact of heavy rain the weather systems in Xishuangbanna,Can be broadly divided into two high-convergence,Shear line,Tropical systems,South Branch of the low pressure trough,Subtropical high external and 500hPa types of six kinds of vortex. Which the water vapor flux in the low-level convergence zone,low-level convergence and high-level divergence field of divergence is the vertical vorticity,as well as increase the speed of motor areas with heavy rain the District a better relationship.