黄土坡面侵蚀方式演变与侵蚀产沙过程试验研究

利用自行设计的双土槽径流小区系统和人工模拟降雨试验研究方法,研究了坡面侵蚀方式演变对坡面侵蚀产沙量的影响,分析了沟蚀发育不同阶段对坡面侵蚀产沙的贡献。结果表明,坡面侵蚀发育初期,沟头溯源侵蚀占主导地位,侵蚀产沙量呈增加趋势;坡面侵蚀发育中期,沟蚀的宽度和深度变化已属于切沟形态发育的范围,导致了侵蚀产沙量的急剧增加;坡面侵蚀发育后期,沟蚀发育过程处于后期稳定阶段,侵蚀产沙量变化伏动较小。在坡面侵蚀发育初期、中期和后期,沟蚀分别占坡面总侵蚀产沙量的28.7%,70.4%和37.1%。

Experimental Study on Erosion Pattern Evolvement and Sediment Process on Loessal Hillslopes

Soil erosion pattern evolvement and their contributions to soil erosion and sediment delivery were qualified using a dual-box system with rainfall simulated experiment.The results showed rill head-cuts was dominant erosion form in initial stages of erosion evolvement process and hillslopoe sediment delivery gradually increased at hillslope in the middle stage of erosion evolvement process,gully head-cuts forward movement,channel deep-cutting,and gully-wall collapsing were dominant,which increased the sediment delivery dramatically;in the last stage of erosion evolvement process,gully development reached to a stable stage and sediment delivery fluctuated little.Gully erosion occupied 28.7%,70.4%,and 37.1% of the total sediment delivery in initial stages,in the middle stage,and in the last stage,respectively.