Variation characteristics of rainfall erosivity in Heilongjiang Province
LIU Yan-Ling-;Liu-Bin-Hui-;Wang-Li-Gang-;Yuan-Wen-Chao
1.College of Forestry,Northeast Forestry University,150040,Harbin;2.Heilongjiang Academy of Forest and Environmental Science,161005,Qiqihaer,Heilongjiang: China
Abstract:We analyzed the relationship between change characteristics of rainfall erosivity and precipitation using daily rainfall data during 1960 to 2000 from 16 weather stations in Heilongjiang Province.The results indicate that: trend of annual rainfall erosivity from 1960 to 2000 is increasing,as same as trend of annual precipitation and trend of erosive precipitation,however,the changes are not significant.The annual rainfall erosivity,annual precipitation and erosive precipitation increase with rate of 1.47 MJ·mm/(hm2·h·a),0.29 mm/a,0.35 mm/a from 1960 to 2000,respectively.There are eleven weather stations that the rates of the tendency are positive,the annual rate of the tendency of rainfall erosivity increase largestly in Mudanjiang,which rate is 15.6 MJ·mm/(hm2·h·a);while there are five weather stations that the rates of the tendency are negative,the annual rate of the tendency of rainfall erosivity decrease the minimum in Qiqihaer,which is-16.8 MJ·mm/(hm2·h·a),all sites' changes are not reach significant level.Apart from(Harbin,Keshan,Huma,Tonghe),the impact of the changes of frequency of erosive rainfall on the changes of erosive rainfall is greater than the impact of the intensity of erosive rainfall on the changes of erosive rainfall in these 16 weather stations.The results can provide a basis for the prediction of soil erosion and planning and decision-making for soil and water conservation.