水土保持学报2011，Vol.25Issue(2)：33-38,6.
黄土高原南部降雨侵蚀力试验研究
Preliminary Study on Rainfall Erosivity in the Southern Loess Plateau
摘要
Abstract
According to the classical algorithm by Wischimeier of rainfall erosivity R= EI30, this study, taken the natural rainfall in Yangling of southern Loess Plateau as the research object, analyzed in detail the size distribution of rainfall during a precipitation process, and regressed the relationship between the median diameter of raindrops, rainfall energy and rainfall intensity,meanwhile, rainfall erosivity from June to September with the indicators of EI10, EI30, EI60 was calculated, as well as the relationship between rainfall erosivity and the rainfall was studied.Results showed that: Size distribution of the raindrop met the distributed formula by Best; The median diameter of raindrops reflected the general trend of rainfall size during the rainfall,and had a close relationship with the rainfall intensity which could be expressed as D50=2.25I0.21; Rainfall kinetic energy derived from the process of raindrops falling from the sky was determined by the raindrop diameter and raindrop velocity, which concluded the relationship between rainfall kinetic energy and rainfall intensity was E=26.57I0.28; Rainfalls focused on June to September in Yangling, and the distribution of rainfall erosivity changed with the monthly rainfall; The order of the rainfall erosivity calculated by three R indicators was EI10＞EI30＞EI60, and compared with results of the CREAMS empirical model for monthly rainfall, its relative deviation of EI10 and the model was minimum, yet its fluctuation range was significant,whereas the relative deviation of EI30 and the model was medium, but it was relevant stable, which suggested EI10 was more appropriate for the short rainfall formation, while EI30 was applicable to common rainfall.Based on the above theory, this study aimed to provide a theoretical basis for the establishment of the rainfall erosivity model in the southern Loess Plateau area.关键词
黄土高原/降雨强度/雨滴中数直径/降雨动能/降雨侵蚀力Key words
Loess Plateau/rainfall intensity/ median raindrop diameter/ kinetic energy of rain/ rainfall erosivity分类
农业科技引用本文复制引用
吴光艳,祝振华,成婧,乌日娜,张由松,吴发启..黄土高原南部降雨侵蚀力试验研究[J].水土保持学报,2011,25(2):33-38,6.基金项目
国家自然科学基金资助项目(40871133) （40871133）
国家重点基础研究发展"973"计划(2007CB407201) （2007CB407201）
