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| Study on rainfall-runoff erosivity index in Northeastern China |
| Jiao Jian1,Xie Yun1,Lin Yan1,Zhao Dengfeng2 |
| 1.State Key Laboratory of Earth Surface Processes and Resource Ecology,School of Geography,Beijing Normal University,100875,Beijing;2.Heilongjiang Water Resource Bureau,150001,Harbin: China |
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Abstract Rainfall-runoff erosivity reflects the erosive forces of rainfall and snowmelt runoff from snowmelt,and the amount and rate of runoff likely to be associated with them.Located at mid-high latitude,soil loss caused by snowmelt runoff is a main part in soil erosion in Northeastern China.For predicting soil erosion by models,it is necessary to quantify snowmelt-runoff erosivity(RW) and rainfall erosivity(R) separately.This paper proposed the method of estimating snowmelt-runoff erosivity by using daily runoff and sediment yield data from 21 typical hydrological stations and daily precipitation records of precipitation stations.Precipitation records from 234 climate stations was used to estimate rainfall-runoff erosivity index(RT).In addition,the spatial distribution of rainfall-runoff erosivity was analyzed.The results show that once the average percent of snowfall to annual precipitation is no less than 10%,snowmelt-runoff erosivity can be estimated by using precipitation amount during November to April(P11-4):RW·h·a) in this region,which increases from the northwest to southeast,with annual rainfall showing a similar pattern.This analysis will improve the accuracy of soil loss prediction and contribute to soil conservation plan in this region.
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Received: 16 June 2008
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