基于日雨量的延安地区降雨侵蚀力动态特征分析  

The Dynamic Feature Analysis of Rainfall Erosivity in Yan'an Area Based on Daily Rainfall Amounts

作　　者：廖鑫[1] 徐学选[2] 刘普灵[2] 

机构地区：[1]西北农林科技大学,陕西杨陵712100 [2]中国科学院水利部水土保持研究所,陕西杨陵712100

出　　处：《水土保持研究》2009年第2期34-37,41,共5页Research of Soil and Water Conservation

基　　金：国家重点基础研究计划(2007CB407205);中科院西部项目(KZCX2-XB2-05)

摘　　要：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 1 765.73 MJ·mm/（hm2·h）,which was a moderate change in the values of erosivity per year.The paper used two indicators to describe the change of annual rainfall erosivity：the coefficient of variation Cv and the coefficient of changed trend r.By calculation,the coefficient of variation Cv was 0.41,the coefficient of changed trend r was-0.071.So the whole trend of the yearly erosivity value among 55 years was balanced.

关 键 词：降雨侵蚀力 日雨量 延安 

分 类 号：S157.1[农业科学—土壤学]