【摘要】 降雨是坡地土壤侵蚀的主要动力,为分析不同降雨过程下的侵蚀规律,在5 m×1.5 m径流小区进行了变雨强连续降雨(VR)与恒定雨强降雨(CR)两组人工模拟降雨试验。结果表明:(1)连续降雨过程中,雨强是影响地表产流的重要因素,随雨强增大,地表径流流量增加。径流含沙量变化过程较为复杂,总体上呈增长趋势,在部分时段可能减小;(2)恒定雨强降雨和变雨强降雨产流过程的差异主要表现在产流初期。变雨强降雨地表产流较快,径流达到稳定时间更短。变雨强降雨和恒定雨强降雨的稳定流量相差不大,相对误差为2.23%~6.64%。(3)恒定雨强降雨和变雨强降雨的产沙过程显著不同,两种条件下的径流含沙量相差6.25%~42.27%。除极高强度降雨时段外,其它时段中变雨强降雨的径流含沙量高于恒定雨强降雨。更多还原

【Abstract】 Rainfall is one of the main agents driving the soil erosion on sloping cropland.To find out the law of soil erosion under different rainfall process,simulated rainfall with constant intensity(CR) and varied intensity(VR) were conducted on 5 m by 1.5 m runoff plot.The results showed that:(1) For varied intensity rainfalls,rain intensity is the critical factor effecting the runoff because discharge increased with rain intensities increasing.However,the process of sediment concentration is complicated since it increased in most scenarios,but decreased sometime.(2) The difference between overland flow of VR and CR can be found at the initial stage of runoff generation.For varied intensity rainfall,overland flow occurred earlier than CR,so as the time reached to steady.The steady discharges displayed no extinct difference between CR and VR with relative error 2.23%~6.64%.(3) The processes of CR and VR showed noticeable discrepancy since the relative error are 6.25%~42.27%.Except for the highest intensity rain,the sediment concentration of VR is always greater than that of CR.更多还原