Abstract:Spatiotemporal characteristics of rainfall erosivity are very important for the understandings of soilerosion processes.Daily rainfall data from 704weather stations of seven provinces in the upper reaches of theYangtze River in past 30years(1980-2010)were used to calculate the average annual rainfall erosivity,average annual half-month rainfall erosivity and the proportion of the annual rainfall erosivity,so as to determine the spatiotemporal distribution of erosive rainfall.Results showed that the highest Rvalue was found tobe 11 394MJ·mm/(hm2·h·a)and the lowest,273MJ·mm/(hm2·h·a).As influenced by terrain,rainfall erosivity presented three high value areas of the Emei Mountains in Sichuan Province,Bijie region inGuizhou Province and Yichang City in Hubei Province.There was a significant correlation between rainfallerosivity and average annual rainfall,with a correlation coefficient R2 of 0.80.In the study area,the seasonaldistribution of rainfall erosivity had a concentration percentage of 69% and was mainly concentrated fromMay to October.