坡度对降雨溅蚀影响的研究  

EFFECTS OF SLOPE GRADIENT ON RAINDROP SPLASH EROSION

作　　者：刘和平[1] 符素华[1] 王秀颖[1] 徐丽[1] 方岚[1] 刘宝元[1] 路炳军 

机构地区：[1]地表过程与资源生态国家重点实验室,北京师范大学地理学与遥感科学学院,北京100875 [2]北京市水土保持工作总站,北京100038

出　　处：《土壤学报》2011年第3期479-486,共8页Acta Pedologica Sinica

基　　金：国家重点基础研究发展计划课题(2007CB407204);国家自然科学基金项目(40201031);北京师范大学优秀博士学位论文培育基金项目资助

摘　　要：利用可以分别收集不同方向溅蚀土样的土槽装置,选取9个坡度（5°-45°）,采用北京的普通褐土,借助人工模拟降雨手段研究了降雨溅蚀的发生过程及溅蚀量与坡度的关系。结果表明,随着坡度的不同,各方向的溅蚀过程呈现三种形式：（1）产流前溅蚀率较小,产流后迅速达到峰值,之后逐渐减小并逐渐达到稳定,峰值与稳定溅蚀率相差2倍以上;（2）产流前溅蚀率最大,产流后迅速减小并趋于稳定;（3）整个降雨过程中没有明显起伏。各个坡度下,次降雨溅蚀量均为上坡最小,下坡最大。上坡和侧坡溅蚀量与坡度成负相关,可分别用直线和指数函数拟合。下坡溅蚀量、溅蚀总分散量和溅蚀净搬运量均随着坡度的增大而先增大后减小,且为线性关系,临界坡度为35°。本研究将有助于深入理解降雨溅蚀侵蚀机理,并可为布设水土保持措施提供理论依据。Slope gradient is an important factor affecting raindrop splash erosion.Hence its effect was investigated using soil trays simulating nine slope gradients（9%,18%,27%,36%,47%,58%,70%,84%,and 100%）,and each soil tray was 0.5 m×0.5 m×0.1 m（horizontal length×width×depth） in dimension,containing loamy soil,collected from Yanqing,Beijing.All the treatments were subjected to a simulated rainfall with a constant intensity of 67 mm h-1 for 1 hour.Specially designed samplers were used to partition total splash into directional components（e.g.upslope,downslope,and lateral）.Results indicate that splash erosion occurred in the following three patterns：（1） the rate was low prior to the generation of runoff,peaked rapidly at the beginning of runoff,decreased gradually and leveled off;（2） the rate was high prior to the generation of runoff and dropped rapidly after runoff was generated and then leveled off at a certain rate;or（3） the rate did not show any obvious fluctuation during the rainfall event.In all the treatments,the upward raindrop splash erosion rate was always lowest and the downward one was the highest.And the downward splash and sideward splash were negatively related to slope gradient and the relationship could be fit with a linear or exponential function.The downward splash erosion varied more obviously than lateral and upslope splash erosion,which indicates that downslope splash erosion is more significantly affected by slope gradient.The downward splash erosion,total splash detachment,and net splash transport increased initially with rising slope,and then decreased at the critical slope gradient,35°（70%）,all showing linear relationships.

关 键 词：坡度 雨滴溅蚀 溅蚀过程 溅蚀总分散 溅蚀净搬运 

分 类 号：S157.1[农业科学—土壤学]