中文摘要：

采用室外人工模拟降雨实验,研究了春季解冻期近地表草甸土解冻深度对该时期坡面降雨侵蚀过程的影响。结果表明：土壤解冻深度对入渗、产流以及侵蚀量有较大影响。由于降雨过程中冻土层逐渐向下移动,解冻土层厚度增加,坡面产流和入渗也随之经历着此消彼长的过程。对同一降雨强度,解冻深度愈小,坡面初始产流时间愈早,前期侵蚀率愈大,土壤侵蚀总量也愈大,但降雨后期侵蚀率增幅减小。随着降雨时间的延长,坡面随解冻深度不同发生不同程度的细沟侵蚀。降雨前期解冻深度越小,降雨过程中发展为细沟侵蚀的时间越早,侵蚀强度也越严重,降雨过程中侵蚀率大小的变化也受到细沟发育程度的影响。

英文摘要：

In this paper the effects of near-surface meadow soil thaw depth in the spring thaw period on sloping land erosion process was studied,using outdoor artificial simulated rainfall experiment.The results showed that the soil thaw depth have great effects on soil infiltration,run-off and erosion.As the frozen soil layer moved down gradually in the rainfall process,the soil thaw depth increased,surface runoff and infiltration have also experienced a shift in the process.Under the same rainfall intensity,the smaller the thaw depth,the sooner the initial slope runoff time,the greater the rate of pre-erosion,soil erosion volume was also greater,but the growth rate of erosion in the late rainfall was decreased.During rainfall process,slope land occurred different degrees of rill erosion with the different thaw depth,the smaller the thaw depth before rainfall,the sooner the occurrence time of rill erosion and the more severe erosion intensity.The fluctuations in the rate of erosion have been influenced mainly by the degrees of rill development.