摘要
降雨侵蚀力(R)反映了降水引起土壤水蚀的潜在能力,其时空分布规律定量研究是进行土壤侵蚀预报的基础.利用延河流域22个雨量站24a逐日降雨资料,分析了该区降雨侵蚀力的时空分布特征.结果表明,降雨侵蚀力与降雨量、侵蚀性降雨量具有一致的年内年际变化趋势.降雨侵蚀力年内变化为单峰型,集中分布在5～9月,占全年R值的91.61%.降雨侵蚀力多年平均值为1580.58MJ.mm.(hm2.h.a)-1,最高值(1981年)为2417.70MJ.mm.(hm2.h.a)-1,最低值(1999年)仅585.29MJ.mm.(hm2.h.a)-1,年际间变化为中等变异,变异系数为0.32.烧房砭站多年平均R值最大,为2190.33MJ.mm.(hm2.h.a)-1,镰刀湾和杨山站多年平均R值最小,分别为1151.37MJ.mm.(hm2.h.a)-1和1146.87MJ.mm.(hm2.h.a)-1.R值与侵蚀性降雨量具有一致的空间分布格局,北部雨量站R值年际变化呈现轻微的增加趋势,其它站点R值年际变化相对呈现出轻微的减少趋势,总体上延河流域降雨侵蚀力呈现下降趋势,趋势系数为-0.004.
Rainfall erosivity （ R） is a measure of effects of the rainfall factor on the potential capacity for soil water erosion. The characteristic of spatial and temporal of R value is the basis for soil erosion prediction. The spatial and temporal distributions of rainfall erosivity were analyzed using daily rainfall data collected between 1980 and 2003 from 22 rainfall stations located across the Yanhe River Basin. The results showed that the seasonal distribution of R values formed a single peak,concentrated between May and September and accounted for 91. 61% of the total annual R value. The changes in annual average rainfall erosivity followed a similar trend to those for the annual average rainfall and erosive rainfall. The average annual R value was 1 580. 58 MJ·mm·（hm^2·h·a）^-1,the maximum annual rainfall erosivity （ 1981 ） was 2 417. 70 MJ·mm·（hm^2·h·a）^-1 and the minimum （1999） was 585. 29 MJ·mm·（hm^2·h·a）^-1. The variation coefficient of annual rainfall erosivity was the medium with a value of 0. 32. The annual rainfall erosivity was the greatest at the Shaofangbian station with a value of 2 190. 33 MJ·mm·（hm^2·h·a）^-1 ,while the least erosivity was found at the Liandaowan and Yangshan station with values of 1 151. 37 MJ·mm·（hm^2·h·a）^-1 and 1 146. 87 MJ.mm.（hm2.h.a） -1 ,respectively. The annual average R values had a similar trend of spatial distribution with annual average erosive rainfall. The annual changes in R values increased at the rainfall stations of north,while those were found to decrease at other stations of Yanhe River Basin. Overall,the annual rainfall erosivity tended to decrease in the Yanhe River Basin with the trend coefficient value of -0. 004.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2010年第4期850-857,共8页
Environmental Science
基金
国家重点基础研究发展规划(973)项目(2007CB407203)
中国科学院水利部西北水土保持研究所黄土高原土壤侵蚀和旱地农业国家重点实验室基金项目(10501-203)
关键词
降雨侵蚀力
通用土壤流失方程(USLE)
趋势系数
时空分布
延河流域
rainfall erosivity
universal soil loss equation （USLE）
trend coefficient
spatial and temporal distributions
Yanhe River Basin
作者简介
刘春利（1980～），女，博士研究生，主要研究方向为土壤环境生态，E-mail：chunliliu@sdu．edu．cn
通讯联系人，E-mail：qkyang@ms．iswc．ac．cn
