降雨强度和坡度双因子对紫色土坡面侵蚀产沙的影响  

Effect of rainfall intensity and slope gradient on soil erosion process on purple soil hill slopes

作　　者：耿晓东[1,2] 郑粉莉[1,3] 刘力[3,4] 

机构地区：[1]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]中国科学院研究生院,北京100049 [3]西北农林科技大学资源环境学院,陕西杨凌712100 [4]四川南充水利电力建筑勘察设计研究院,四川南充637000

出　　处：《泥沙研究》2010年第6期48-53,共6页Journal of Sediment Research

基　　金：国家重点基础研究发展计划项目课题"不同类型区土壤侵蚀过程与机理"(2007CB407201);西北农林科技大学创新团队建设计划项目"土壤侵蚀及其治理环境效应评价"(01140202)

摘　　要：利用室内模拟降雨试验研究了降雨强度和坡度双因子对紫色土坡面侵蚀产沙过程的影响。试验结果表明:坡面产沙过程和侵蚀形态的演变与降雨强度和坡度的变化密切相关,降雨强度和坡度增大使径流量很快达到细沟发生的临界流量并加剧细沟形态的演变过程,产沙率由于细沟的产生和发展而急剧增加,并呈现跳跃性的波动。各降雨强度下,在5°～25°范围内,侵蚀量随坡度的增大而增大,30°时开始减小,在25°附近存在坡面侵蚀的临界坡度。降雨强度和坡度两个因子对侵蚀量的贡献率存在对比消长关系。降雨强度和坡度都较小时,坡度对侵蚀过程起主导作用;当降雨强度较大或者达到临界坡度以后,则降雨强度对侵蚀过程起主导作用。The runoff and sediment yield are strongly affected by the rainfall intensity and slope gradient.The laboratory experiment was conducted under simulated rainfalls to evaluate the effects of different rainfall intensities and slope gradients on sediment yield on the purple soil hill slope.The results show that the soil erosion processes and the changes of erosion type are closely related to rainfall intensity and slope gradient,and the sediment delivery rate is drastically increased and erratically fluctuate due to the occurrence and development of the rills during rainfall.The increase of rainfall intensity and slope gradient can reduce the critical runoff of occurrence of rills and accelerate the changes of rill morphology.For all the three rainfall intensities,both the total runoff and sediment yield increased with the rainfall intensity and slope gradient in the range of 5° ～ 25°,and reached the peak values at 25° slope,and then decreased at 30°slope.It indicated that there was a critical slope between 25° ～ 30°.The contribution ratio of rainfall intensity and slope gradient on the total sediment yield varied at different slope gradients,the slope gradient played a leading role under low rainfall intensity,while the rainfall intensity played a leading role under high rainfall intensity.

关 键 词：降雨强度 临界坡度 双因子 紫色土 坡面侵蚀 侵蚀产沙过程 PURPLE SOIL SOIL erosion process 主导作用 侵蚀过程 侵蚀量 演变过程 侵蚀形态 消长关系 试验研究 试验结果 模拟降雨 临界流量 跳跃性 径流量 

分 类 号：TV14[水利工程—水力学及河流动力学]