摘要
片蚀过程是坡面径流侵蚀过程的第一阶段和侵蚀方式演变的初始形态,阐明坡面片蚀过程可为坡面侵蚀过程模型建立和坡面水土流失治理提供重要科学依据。采用人工模拟降雨试验方法对黄土坡面片蚀过程进行了研究,结果表明:不同雨强及不同坡度下,坡面片蚀率皆随降雨历时的增长呈先急剧增大后趋于稳定的变化趋势,变化的转折点为产流后的5min左右;坡面片蚀模数随雨强和坡度的增大均呈显著的增加,可分别用指数方程和对数方程描述;雨强和坡度对片蚀模数的综合影响可以用二元幂函数方程描述,其中,坡度的影响大于雨强;水流功率是试验条件下与坡面片蚀动力学过程关系最密切的水动力学参数,坡面片蚀动力学过程的发生发展根源于坡面薄层径流的水流功率的动力作用。采取有关水保措施减低地面坡度,增加地面入渗,降低坡面径流流速可以有效地减少坡面片蚀。
As sheet erosion processes being the first stage and initial form of the evolvement of the erosion on slope,the study of sheet erosion processes plays a great role in modeling the erosion processes and providing a basis for erosion control.An experimental research on sheet erosion processes on loess slope was carried out,and the results showed that erosion rates increased sharply then went to smooth with time both under different rainfall intensities and under different slope gradients,with the turning point at the five minutes around;Sheet erosion modulus increased with both rainfall intensities and slope gradients,and could be described by exponential equation and logarithmic equation respectively;The synthetic effect of rainfall intensities and slope gradients to sheet erosion modulus could be described with binary power equation,and slope gradients had the greater positive effect;Stream power was the best parameter closely related to the dynamic sheet erosion processes in this experiment,so the source of the generation of sheet erosion on loess slope was the motive function of stream power of sheet flow.Hereby,to reduce erosion effectively,some measures could be done to gentle the slope,higher infiltration and decrease the velocity of sheet flow.
出处
《水土保持学报》
CSCD
北大核心
2011年第3期35-39,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金“黄土坡面细沟侵蚀动力学过程组合小区试验研究”(40971172)
国家“973”计划课题“不同类型区土壤侵蚀过程与机理”(2007CB407201)
中科院知识创新工程重要方向项目课题“多沙粗沙区土壤水蚀机理研究”(KZCX2-YW-442-04)
黄土高原土壤侵蚀与旱地农业国家重点实验室专项经费“坡面水流及其输沙侵蚀动力学特征”(10502-Z12-7)
关键词
黄土坡面
片蚀
薄层水流
水流功率
loess slope
sheet erosion
sheet flow
stream power
