鄱阳湖流域次降雨等级及其对降雨侵蚀力的贡献  

Grade of Single Rainfall and Its Contribution to Rainfall Erosivity in Poyang Lake Basin

作　　者：何小武[1] 肖屿昆 王艳艳 吴星 李凤英[1] 陈娇 李文斌 HE Xiaowu;XIAO Yukun;WANG Yanyan;WU Xing;LI Fengying;CHEN Jiao;LI Wenbin(College of Land Resources and Environment,Jiangxi Agricultural University,Nanchang 330045,China;Jiangxi Academy of Water Science and Engineering,Nanchang 330029,China)

机构地区：[1]江西农业大学国土资源与环境学院,江西南昌330045 [2]江西省水利科学院,江西南昌330029

出　　处：《江西农业大学学报》2023年第6期1588-1600,共13页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家自然科学基金项目(42167045,31300594);江西省“科技+水利”联合计划项目(2023KSG01004)

摘　　要：【目的】降雨等级的划分有助于正确认识不同量级降雨对土壤侵蚀的影响,为水土流失防治决策提供科学依据。【方法】基于鄱阳湖流域16个气象站点1991—2020年的降雨数据,在日降雨等级划分标准的基础上,从土壤侵蚀动力角度出发,采用最小偏差法,分析次降雨与日降雨之间的对应关系,以确定次降雨等级。同时,利用时间序列分析方法(变差系数、倾向率、Mann-Kendall趋势检验)对各等级降雨进行年内、年际变化特征研究,分析该流域各等级次降雨对降雨侵蚀力的贡献。【结果】(1)次降雨中雨、大雨、暴雨的理论上限值分别为31.3 mm、64.6 mm、150.9 mm。(2)30年来鄱阳湖流域总降雨、非侵蚀性降雨和侵蚀性降雨的降雨场次均呈增加趋势,降雨总量和侵蚀性降雨量亦呈增长趋势,但非侵蚀性降雨量呈下降趋势。(3)各等级降雨在年内均呈现年初开始上升、至3—6月出现高值,随后呈总体下降趋势。(4)总降雨、中雨、大雨、暴雨和大暴雨等级次降雨侵蚀力密度随时间变化的倾向率分别为0.34、0.04、0.31、0.32和1.25 MJ/(hm^(2)·h·10a),均为正值。(5)中雨、大雨、暴雨、大暴雨对降雨侵蚀力的贡献率分别为17.17%、34.01%、34.89%、13.93%。【结论】(1)鄱阳湖流域次降雨的小雨、中雨、大雨、暴雨、大暴雨划分的雨量值分别为0~14 mm、14~31 mm、31~65 mm、65~151 mm、≥151 mm。(2)流域总降雨场次和总降雨量均为增长趋势。其中,降雨场次的增加主要以非侵蚀性降雨(即小雨)的显著性增加为主,但非侵蚀性降雨量不增反减,总降雨量的增加均体现为侵蚀性降雨。(3)流域内各等级降雨具有明显的季节性分布特征,其中大暴雨具有异常的集中性。侵蚀性降雨主要发生在雨季(3—9月)。(4)流域的降雨侵蚀力主要取决于暴雨和大雨,各等级降雨对降雨侵蚀力的贡献率由大到小依次为暴雨、大雨、中雨、大�[Objective]The classification of rainfall grade is helpful to understand correctly the influence of different amount of rainfall on soil erosion and provide a scientific basis for the prevention and control of soil erosion.[Method]Based on the single rainfall data of 16 meteorological stations in Poyang Lake Basin from 1991 to 2020,and the classification standard of the meteorological daily rainfall grade,the minimum deviation method was used to determine the grade of individual rainfall.Meanwhile,time series analysis methods including coefficient of variation,trend rate,and Mann-Kendall trend test were used to study the intra-annual and inter-annual variations of rainfall of different grades.The contribution of each grade of single rainfall to rainfall erosivity was also analyzed.[Result]The results showed that:(1)The theoretical upper limits of moderate rain,heavy rain and rainstorm are 31.3 mm,64.6 mm and 150.9 mm,respectively.(2)The number of total single rainfall,non-erosive single rainfall and erosive single rainfall increased in last 30 years,the amount of total rainfall and erosive individual rainfall also increased.However,the amount of non-erosive individual rainfall decreased.(3)The amount of all the grades of single rainfall increased from the beginning of the year,and reached the peak value between March and June.After that,the amount decreased totally.(4)The trend rate of total rainfall,moderate rainfall,heavy rainfall,rainstorm and individual heavy rainstorm were 0.34 MJ/(hm^(2)·h·10a),0.04 MJ/(hm^(2)·h·10a),0.31 MJ/(hm^(2)·h·10a),0.32 MJ/(hm^(2)·h·10a)and 1.25 MJ/(hm^(2)·h·10a),respectively.(5)The contribution rate of moderate individual rainfall,heavy individual rainfall,individual rainstorm and individual heavy rainstorm were 17.17%,34.01%,34.89%and 13.93%,respectively.[Conclusion](1)The threshold of individual rainfall value for light rain in Poyang Lake Basin was 0-14 mm,and that for moderate rain,heavy rain,rainstorm and heavy rainstorm was 14-31 mm,31-65 mm,65-151 mm and≥151 mm,r

关 键 词：次降雨等级 划分 日降雨等级 贡献率 降雨侵蚀力 鄱阳湖流域 

分 类 号：S157.1[农业科学—土壤学] S161.6[农业科学—农业基础科学]