摘要
降雨动能是土壤侵蚀的重要影响因素,已有研究拟合了降雨动能KE与降雨强度I(简称雨强)的多种经验关系模型,但缺少相应的理论分析。为揭示降雨动能与雨强的理论关系,基于雨滴谱的Gamma分布,推求了降雨动能与雨强关系的理论公式KE=AI m,其中A与m为参数;并利用清华大学榆林生态水文观测站设立的德国OTT Parsivel-2雨滴谱仪2018年6月10日—8月10日及2019年6月10日—8月10日的观测数据,对理论公式进行分析。结果表明:该理论公式能很好地描述该地区降雨动能与雨强的关系,该关系受降雨特性及环境条件影响;参数A与雨滴密度、降雨形状因子、环境条件因子及雨滴形变程度相关,m与降雨形状因子和雨滴形变程度相关,由榆林站实测数据分析得出A的变化范围为2.7~12.8,m的变化范围为1.2~1.6。研究还发现,已有的经验关系可以表示为该理论公式在不同参数取值下的近似。
Rainfall kinetic energy(KE)is an important influence factor on soil erosion,and it is usually estimated by using empirical formulas from rainfall intensity(I).Therefore,based on the Gamma distribution of raindrops,this study firstly derived the theoretical formula,a power function KE=AI m between rainfall kinetic energy and rainfall intensity,where A and m are parameters.Furthermore,this study validated this theoretical formula based on nine rainfall events observed by an OTT Parsivel-2 raindrop spectrometer during the period from 10 June 2018(2019)to 10 August 2018(2019)in Yulin Ecohydrological Station,Shaanxi Province.The theoretical formula can well describe the relationship between KE and I,which is influenced by rainfall characteristics and environmental conditions.The parameter A is related to raindrop density,rainfall shape parameter,meteorological factors and deformation of raindrops,and the parameter m is related to rainfall shape parameter and deformation of raindrops.The measured results of Yulin Ecohydrological Station were calculated,and the variation range of parameter A in KE=AI m is 2.7~12.8,and parameter m is 1.2~1.6.The existing empirical relationships can be approached by adjusting the parameters of the theoretical formula.
作者
谢宗旭
杨汉波
吕华芳
XIE Zongxu;YANG Hanbo;LYU Huafang(State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China)
出处
《水利水电技术（中英文）》
北大核心
2021年第1期22-32,共11页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(51622903,51809147)
水沙科学与水利水电工程国家重点实验室自主课题(2017-KY-01)。
关键词
雨滴谱仪
降雨强度
降雨动能
雨滴直径分布
raindrop spectrometer
rainfall intensity
raindrop kinetic energy
raindrop size distribution
