Abstract:

Anhui Province is a special region for climate in China as it is over two climatic zones.The characteristics and influential factors of precipitation in different fields are various.The main object of this study is to investigate the distribution and find out the influential factors of precipitation in summer over Anhui. For this goal,the meteorological observation data of 78 stations form 1971 to 2008 were collected and analyzed.During the analysis,the percent of different intensity rainfall and the ratio between storm days and rainfall days were calculated. Finally, the temporal variations of meteorological observation data were analyzed.The results show that rainfall were effected by several factors, such as terrain, moisture, temperature, wind and so on. According to the difference of position and influential factors,Anhui Province was divided into 10 regions,which were climatic storm region,climatic rain region,weakly rain region along Huaihe River,lee weakly rain region on the north of the Yangtze River,hilly convective rain region,Dabieshan topographic rain region,high temperature storm region,lee weakly rain region on the north of the Yangtze River,irregular rain region along the Yangtze River and Wannan topographic storm region.On the other hand, there were typical characters in rainfall temporal variety.That is the percent of storm cases and ratio of storms to rainfall were increasing with the decreasing of rainfall cases from 1971.For the analysis of spatial and temporal characters of precipitation in Anhui Province,two main views could be concluded.First,with the changing of climate,the precipitation of Anhui province was became heterogeneous in spatial and temporal distribution.Second,the heavy rain cases such as storm occurred more frequently than before