不同植被类型的坡面径流侵蚀产沙试验研究

Effects of vegetation types on hillslope runoff-erosion and sediment yield

  • 摘要: 利用野外模拟降雨试验,研究不同植被类型的侵蚀产沙、径流、地表糙度和入渗规律以及相关关系。结果表明,植被对水沙调控作用大小依次为:植物根系,整个坡面植被,坡面下部植被和坡面上部植被。林草地具有蓄水减沙的水土保持措施功效,该机制通过植物根系对水沙的调控作用实现;草地具有直接拦沙的水土保持功效,该机制通过地表植被对水沙的调控作用体现。累计产沙量随累计径流量呈幂函数递增趋势,具有很好的相关性;坡面径流产沙过程分为发育期、活跃期和稳定期3个阶段。植被覆盖度越大,地表糙度变化越小。

     

    Abstract: A expermient study was conducted to explore the effect of vegetation types on hillslope runoff, erosion, sediment yield,surface roughness and infiltration,as well as the interrelation among these elements. Results reveal that the effectiveness of vegetation regulating on hillslope runoff and sediment yield is in the folowing order:the plant root, the fully vegetated hillslope surface,the vegetation cover at the lower end of hillslope,and the vegetation cover at the upper end of hillslope. The forest-grassland regulates water storage and sediment yield through its rich root networks.Sedimentation retaining is directly achieved by the surface vegetation of grasslands.The cumulative sediment yield and the cumulative runoff are found to be exponentialy correlated.There are three stages of developing,active and stable in the development of hillslope runoff and sediment yield.The richer the vegetation coverage is,the less the surface roughness is.The result is useful for understanding of the runoff generation process at a catchment scale and provides reliable experimental in formation for the model development.

     

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