基于日雨量的延安地区降雨侵蚀力动态特征分析

延安地区是黄土高原水土流失最为严重的地区之一。利用延安气象站1951-2005年的日降雨量数据,采用日雨量侵蚀力模型估算延安地区降雨侵蚀力,结果表明:该地区降雨侵蚀力主要集中在6-9月,占到了全年的85.6%。年降雨侵蚀力的平均值为1765.73MJ.mm/(hm2.h),55年间,年降雨侵蚀力变异程度适中,从整体上看,趋势保持平稳,其离差系数Cv和变异趋势系数r分别为0.41和-0.071。

Yan an is one of the areas in which the soil erosion is most serious on the loess plateau.Rainfall erosivity in Yan an area was estimated by the method of a simple model based on daily rainfall amounts using daily rainfall amounts data from 1951 to 2005 of Yan an weather stations.The results showed that the monthly rainfall erosivity mainly concentrated from June to September;the rainfall erosivity of this period is 85.6% of annual rainfall erosivity.The annual average value of rainfall erosivity was 1 765....