多场次降雨条件下不同土岩镶嵌坡面土壤侵蚀特征  

Soil Erosion Characteristics of Different Soil and Rock Mosaic Slopes Under the Condition of Successive Rainfalls

作　　者：樊春华 赵龙山[1,2,3] 方乾 李开凤 钱晓鹤 FAN Chunhua;ZHAO Longshan;FANG Qian;LI Kaifeng;QIAN Xiaohe(College of Forestry,Guizhou University,Guiyang 550025,China;Research Institute of Forestry,Chinese Academy of Forestry,Beijing 100091,China;Research Centre for Soil Erosion&Eco-Restoration Sciences,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学林学院,贵阳550025 [2]中国林业科学研究院林业研究所,北京100091 [3]贵州大学土壤侵蚀与生态修复研究中心,贵阳550025

出　　处：《土壤学报》2022年第5期1270-1278,共9页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41867014);贵州省优秀青年科技人才项目(黔科合平台人才[2019]5671);贵州省科技拔尖人才项目(黔教合KY字[2021]025);中国博士后科学基金资助(2020M670527)。

摘　　要：为探究多场次降雨条件下喀斯特区不同土岩镶嵌坡面土壤侵蚀特征,采用人工模拟降雨方法,研究了四场次(每场间隔24 h)降雨条件下,三类土岩镶嵌坡面(岩石嵌入土层,未露出地表(全埋);岩石嵌入土层,露出地表(半埋)和岩石未嵌入土层,覆盖在地表(覆盖))的土壤侵蚀特征。试验坡度为25°,降雨强度为50 mm·h^(–1),降雨历时为90 min。结果表明:(1)随降雨场次增加,全埋、半埋和覆盖地表径流量增大,而壤中流量和地下径流量则呈先增大后减小的特征。在前两场降雨中,三类土岩镶嵌坡面的地表径流量无明显规律,但后两场降雨中地表径流量呈现为半埋>全埋>覆盖;(2)随降雨场次增加,全埋、半埋和覆盖地表产沙量增大。除第一场降雨外,后三场降雨中半埋产沙量是全埋和覆盖的1.04倍~4.82倍;(3)在多场次降雨条件下,受前期降雨影响土壤含水量增大,后续降雨中地表径流和壤中流产流时间提前5~16 min。总之,在多场次降雨条件下,岩石嵌入土壤可以增加地表产流产沙。研究结果为进一步认识喀斯特石漠化坡地水土流失过程对气候变化的响应提供了科学依据。【Objective】The discontinuity of natural rainfall makes the influence of successive rainfalls on soil erosion different from that of single rainfall on slope erosion.Under the condition of not disturbing the slope after rainfall,the soil erosion characteristics of different soil and rock mosaic slopes in karst area under conditions of successive rainfalls were explored.【Method】Using the method of artificial rainfall simulation,the soil erosion characteristics of three types of soil and rock mosaic slopes(i.e.,FE,rock fully embedded in the soil layer,not exposed to the surface;PE,rock partly embedded in the soil layer,exposed to the surface;RC,rock not embedded in the soil layer,covering the surface)were studied under four rainfall conditions(24 h interval).The test slope was 25°,and the rainfall intensity was 50 mm·h^(–1).The rainfall lasted for 90 min.【Result】Results showed that(1)with the increase of rainfall events,the surface runoff of FE,PE and RC increased,while the interflow and the underground runoff increased first and then decreased.In the first two rainfall scenarios,the surface runoff of three types of soil rock mosaic slope had no obvious regularity,but in the last two rainfall,the surface runoff was PE>FE>RC;(2)with the increase of rainfall events,the FE,PE and RC surface sediment yield increased.In addition to the first rainfall,the surface sediment yield in the last three rainfalls was PE>FE>RC.Also,the sediment yield of PE surface was 1.04-4.82 times that of the FE and RC surfaces,respectively;(3)with an increase of rainfall events,under the influence of early rainfall,the soil moisture content increased,and the runoff time of surface runoff and interflow in subsequent events was advanced by 5-16 min.【Conclusion】Under successive rainfalls,the rock embedding in the soil has the effect of increasing the surface runoff and sediment yield.These results provide a scientific basis for further understanding the response of soil and water loss process to climate change on karst rocky d

关 键 词：多场次降雨 基岩裸露 土壤侵蚀 石漠化 地下径流 

分 类 号：S157.1[农业科学—土壤学]