安徽暴雨落区与一些物理量关系的统计分析

从概率统计的思路出发，用1994-2003年的降水资料对安徽省夏半年（4—9月）暴雨落区、频数等与5840gpm线的关系进行了统计分析，并用2003年淮河洪涝期间20个暴雨区域与某些实况物理量场对比，分析了暴雨落区与一些物理量分布的关系，表明了安徽省暴雨主要集中在梅雨期到7月份，暴雨日数多寡和暴雨范围大小，基本上主导汛期降水多少和旱涝趋势。暴雨落区集中出现在5820～5840gpm的区域，而〈5750gpm和〉5870gpm的区域很少出现暴雨。因此梅雨期主雨带位置预报大致可以用5840gpm线的移动作参考。在物理量上，西风急流北侧以及500hPa上升运动中心南侧到850hPa上升运动中心北侧，有利于暴雨发生发展。

Relationship between Rainstorm Areas and Some Physical Variables

Based on the latest 10-year precipitation data, the relationship between the rainstorm areas, frequency etc. from April to September in Anhui Province and the 5840gpm isoline is statistically analyzed. And the comparisons between 20 rainstorm areas and some realtime physical variables during the flood season of the Huaihe River in 2003 are made. It shows that the rainstorm in Anhui Province mainly appears in the period from Meiyu season to July, and both the rain day number and the range of rainstorm basically determine the precipitation amount in flood season and the tendency of flood/drought. The rainstorm areas are concentrated on the 500hPa slope ranging from 5820gpm to 5840gpm while there is seldom rainstorm in the ranges less than 5750gpm and more than 5870gpm. Therefore, the prediction of main rainfall belts during the Meiyu season can refer to the movement of 5840gpm isoline. As to the physical variables, the regions in the north flank of westerly jet and those from the south flank of 500hPa ascending center to the north flank of 850hPa ascending center are favorable for the occurrence and development of rainstorm, whereas the stability in the mid-low troposphere and the 500hPa divergence have no close relationship with rainstorm areas.