【摘要】 降雨侵蚀力是土壤侵蚀评估模型中的一个基本因子,利用长江上游361个测站1961-2004年日雨量资料估算降雨侵蚀力R值,利用GIS空间分析功能,获得长江上游降雨侵蚀力分布图、降雨侵蚀力年际变化趋势图、各区域R值平均年内分配曲线,在此基础上分析长江上游降雨侵蚀力时空分布特征。研究表明长江上游降雨侵蚀力的地域差异十分显著,与降雨量空间分布近似,由东向西减少,且降雨侵蚀力大的区域与多雨中心和暴雨中心分布基本一致。降雨侵蚀力年际变化存在明显的空间差异性,在一些地区年降雨侵蚀力的变化与年降雨量的变化趋势不一致。各区域降雨侵蚀力年内分配曲线为尖峰状分布,降雨侵蚀力十分集中。更多还原

【Abstract】 Rainfall erosivity is one of the fundamental factors in soil erosion evaluation model.Daily rainfall data recorded by 361 meteorological stations in the Upper Yangtze River Basin from 1961 to 2004 was used to estimate rainfall erosivity R.Based on spatial analysis function in GIS,rainfall erosivity distribution map,inter-annual rainfall erosivity trend map as well as seasonal distribution curve of average annual rainfall erosivity in the Upper Yangtze River Basin were acquired to analyze the spatial and temporal characteristic of rainfall erosivity.Results show that there is significant spatial difference of rainfall erosivity in the Upper Yangtze River Basin.The spatial distribution of rainfall erosivity is close to that of rainfall which decrease from the east to the west.The spatial distribution of high rainfall erosivity is nearly the same as that of heavy and intensified rainfall.There is obvious spatial difference in the inter-annual rainfall erosivity variation.In some area,the annual variation of rainfall erosivity is not consistent with that of rainfall.The seasonal distribution of average annual rainfall erosivity is highly concentrated in certain time period of the year.更多还原