Estimation of rainfall erosivity using rainfall amount and rainfall intensity

Abstract

Rainfall erosivity shows the potential ability of the soil loss caused by rainfall and is very important for predicting soil loss quantitatively.It is estimated by the product of the rainfall energy and maximum 30 minute rainfall intensity, which combined the effects of soil detachment by the raindrops on the soil surface and runoff transportation. This study is to determine the rainfall erosivity index used in China for plotting isoerodent map accurately by using detailed available weather station data.Data of rainfall and soil loss for 12 plots representing the main climate zones in China and rainfall data from 14 weather stations were used to analyze the relationship between rainfall characteristics and soil loss in different regions. The rainfall erosivity index used in China was determined to be PI 10 , where P is the rainfall amount and I 10 is the maximum 10-minute rainfall intensity. To keep the unit identical and the result comparable, the relationship for transferring from PI 10 into EI 30 were formulated:(EI 30 ) = 0.1773(PI 10 ).