Based on field hydrological data from 1995 to 2010

the article analyzed the characteristics of precipitation and its effect on soil erosion in Uuanchuan River basin

Dingxi County

Uansu Province and concluded that:Firstly

most of the rainfall occurred from May to September

while erosive rainfall concentrated in July and August.Within the 15 years

erosive rainfall days accounted for 9.53%of annual rainy days and erosive precipitation accounted for 39.41%in total amounts.Secondly

about 1123 rainy days were observed during the 15 years with a total precipitation amount of 4866.98 mm and mean precipitation of 304.19 mm.No obvious trend was found during the 15 years.The proportion of days with erosive rainfall was about 10%annually.Thirdly

a strong positive relationship were found between river runoff and soil erosion(P<0.001)

both of which decreased over time.The precipitation effect on soil erosion delayed when soil was dry.Finally

because water erosion process is quite complex

rainfall amount

erosive rainfall amount

rainfall erosivity can not reflect soil erosion independently.