降雨类型对褐土横垄坡面土壤侵蚀过程的影响  

Effects of rainfall patterns on hillslope soil erosion process of cinnamon soil in contour ridge system

作　　者：安娟[1] 于妍 吴元芝[1] An Juan;Yu Yan;Wu Yuanzhi(Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resources and Environment, Linyi University, Linyi 276005, China)

机构地区：[1]山东省水土保持与环境保育重点实验室,临沂大学资源环境学院,临沂276005

出　　处：《农业工程学报》2017年第24期150-156,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金青年项目(41301292);国家级大学生创新创业训练计划项目(201610452018)

摘　　要：雨型是影响土壤侵蚀过程的重要因子之一,而影响效应与耕作措施密切相关。目前,雨型对横垄坡面土壤侵蚀过程的影响机制尚不清楚。该文以褐土横垄坡面为研究对象,设计了平均雨强和降雨量相同的4种雨型(增加、减弱、增加-减弱和减弱-增加型),采用可同时调节垄向和坡面坡度的土槽进行模拟降雨,研究各个雨型下不同侵蚀阶段的产流产沙特征。结果表明:雨型间的径流量和侵蚀量在细沟间和细沟侵蚀阶段均差异显著,且差异在细沟阶段体现的更为明显。雨型间径流量的大小顺序为增加-减弱型>减弱型>减弱-增加型>增加型,侵蚀量则为增加-减弱型>减弱-增加型>减弱型>增加型。给定雨强下(30、60或90 mm/h),径流量、径流贡献率和侵蚀量贡献率均随降雨过程中雨强发生时序的延迟而增加,而单位径流侵蚀量呈相反趋势;雨型间给定雨强同一发生时序下的径流量和侵蚀量及其它们对总径流量和总侵蚀量的贡献率均差异显著。4种雨型下,幂函数均能很好的描述细沟间和细沟侵蚀阶段内产沙率与径流率间的关系,且方程中的指数均低于2,但雨型间幂函数方程中的指数存在明显差异。以上研究结果有助于深入理解褐土垄作系统下的土壤侵蚀机理,并为横坡垄作的合理利用提供科学指导。Varying of rainfall intensity during rainfall events is a common phenomenon,and soil erosion processes are strongly affected by intra-storm variations in rainfall characteristics.In general,the combination of rainfall intensities in the rainfall process can be regarded as the storm pattern.In agricultural fields,the influence of storm patterns on erosion processes is largely related to tillage treatments.Contour ridging is an effective soil conservation practice and is used throughout the world.However,less information is available regarding the effect of storm pattern on soil erosion processes in a contour ridge system.In this study,the rainfall simulation experiment was conducted to determine the characteristics of runoff and sediment yielding during inter-rill and rill erosion stages under4storm patterns(the rising,falling,rising-falling,and falling-rising patterns)for cinnamon soil in a contour ridge system.And the ridge direction and field slope could be simultaneously changed in the experimental plot.Each storm pattern included3rainfall intensities,i.e.30,60and90mm/h,which respectively lasted for20min during rainfall and comprised the same total rainfall amount and kinetic energy.Results showed that not only the total runoff but also sediment yield exhibited significant differences among storm patterns during both inter-rill erosion and rill erosion stages.Runoff for varied storm patterns was ranked in the following order:falling-rising>falling>rising-falling>rising pattern,but the difference in sediment yield showed a sequence of falling-rising>rising-falling>falling>rising pattern.Runoff from the falling-rising,falling,and rising-falling patterns increased by1.49,1.41,and1.25times,respectively,compared to that from the rising pattern,while the corresponding increase ratio of sediment yield was43.03%,3.30%,and10.03%,respectively.However,the differences were more pronounced during the rill erosion stage.Compared with the rising pattern,runoff and sediment yield from the falling,falling-rising patterns and r

关 键 词：土壤 侵蚀 径流 横坡垄作 褐土 模拟降雨 雨型 

分 类 号：S157[农业科学—土壤学]