降雨类型对北方土石山区坡面土壤侵蚀的影响  

Effect of rainfall patterns on hillslope soil erosion in rocky mountain area of north China

作　　者：邬铃莉 王云琦[1,2] 王晨沣 王玉杰 王彬[1,2] Wu Lingli;Wang Yunqi(Chongqing Jinyun Forest Ecosystem Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China;Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China)

机构地区：[1]北京林业大学水土保持学院,重庆缙云山三峡库区森林生态系统国家定位观测研究站,北京100083 [2]北京市水土保持工程技术研究中心,北京100083

出　　处：《农业工程学报》2017年第24期157-164,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：中央高校基本科研业务费专项资金资助(2015ZCQ-SB-01)

摘　　要：该文基于北京市房山区蒲洼径流小区2013-2015年观测的105场自然降雨,采用实测水文数据与WEPP模型模拟降雨侵蚀过程相结合的方法,对比了北方土石山区不同雨型下的坡面土壤侵蚀差异。结果表明:1)自然降雨中,单场降雨的侵蚀能力表现为B型雨(低频率、短历时、中雨量、大雨强)>A型雨(中频率、长历时、大雨量、中雨强)>C型雨(高频率、中历时、小雨量、小雨强),其中,侵蚀性降雨中A型雨降雨频率最高、对研究区土壤侵蚀的累计贡献率最大;而C型雨几乎不会引发土壤侵蚀。2)诱发北方土石山区棕壤坡面土壤侵蚀的临界雨量为8 mm、临界雨强为9.5 mm/h。3)利用WEPP模型通过设置最大30 min雨强I30出现的不同时间将3类雨型进一步划分为4个子雨型,结果表明同一雨强出现的降雨时序差异会影响土壤侵蚀的发生程度,且子雨型下土壤侵蚀量整体表现为递增型>峰值型>递减型>均值型,其中A型雨4个子雨型下侵蚀量差异最显著。研究结果可为北方土石山区棕壤坡面土壤侵蚀预报模型的建立及土壤侵蚀防治提供参考依据。In order to make clear the slope soil erosion difference under different rainfall patterns in rocky mountain area of North China,a method combining meteorology and hydrology data with WEPP model to simulate rainfall erosion process was adopted,based on the observation data of105individual rainfall events from2013to2015in field runoff plots of Puwa,Fangshan District,Beijing City.Taking rainfall amount,rainfall duration and average rainfall intensity as the characteristic indices,with R software,105natural rainfalls were divided into3rainfall patterns A,B and C,and the cluster analysis method was used.The results showed that the erosion ability of the3rainfall patterns followed the order of Type B(low frequency,short duration,medium amount of rainfall and strong rainfall intensity)>Type A(medium frequency,long duration,great amount of rainfall and medium rainfall intensity)>Type C(high frequency,medium duration,minor amount of rainfall and low rainfall intensity).However,in the erosion rainfall events,the main rainfall pattern was Type A,which made the highest cumulative contribution rate to soil erosion in the study area,and Type C could hardly cause soil erosion.By analyzing the influence of single rainfall index(rainfall amount,rainfall duration and maximum30-minute rainfall intensity)on soil erosion,it was found that the erosion ability of3types of rainfall in unit time was Type B>Type A>Type C.The critical rainfall amount of soil erosion on brown soil slope in rocky mountain area of North China was8mm and the critical rainfall intensity was9.5mm/h.In order to explore the influence of time sequences on soil erosion,with WEPP model,the3types of rainfall patterns mentioned above were further classified into4sub-rainfall types by setting different occurrence time of maximum30-minute rainfall intensity in the process of rainfall with the WEPP model.Namely,when the value was set to0,the sub-rainfall type was uniform type.Similarly,the value of10%corresponded to decreasing type,50%corresponded to peak type and90%corr

关 键 词：土壤 侵蚀 径流 雨型 径流小区 WEPP模型 北方土石山区 

分 类 号：S157.1[农业科学—土壤学]