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为研究草地对土壤侵蚀过程的影响,选用黄绵土人工种植草地,采用室内模拟降雨试验研究黑麦草不同覆盖度(0、25%、50%和75%)对3种降雨强度(60、90和120 mm/h)坡面产流产沙过程的影响。结果表明:黑麦草覆盖可以显著减小侵蚀产沙。在坡面土壤预饱和的条件下,坡面产流、产沙与时间呈线性关系;累计产流量随降雨强度线性增加;同一降雨强度条件下,草地覆盖度对累计产流量影响不显著;草地坡面水流含沙量、输沙率、次降雨产沙量均随覆盖度增大而降低,随降雨强度增大而增加;3种降雨强度条件下,无黑麦草覆盖坡面水流含沙量差异不显著,次降雨产沙量和输沙率随着降雨强度的增加而增大。研究结果可为土壤侵蚀预报模型建立及水土保持措施的制定提供理论参考。
In order to study the effect of grassland on soil erosion, we selected artificial artificial grassland from Loess Plateau and studied the effects of different coverage (0,25%, 50% and 75%) of ryegrass on three rainfall intensities (60, 90 and 120 mm / h) runoff and sediment yield. The results showed that ryegrass coverage could significantly reduce erosion and sediment yield. Under the condition of pre-saturated soil, the runoff and sediment yield of slope were linear with time. The cumulative runoff increased linearly with rainfall intensity. Under the same rainfall intensity, the grass coverage had no significant effect on the cumulative runoff. Slope sediment concentration, sediment transport rate, secondary rainfall and sediment yield decreased with the increase of coverage, and increased with the increase of rainfall intensity. Under three kinds of rainfall intensity, ryegrass-covered slope sediment concentration The difference was not significant. The amount of secondary sediment and sediment transport increased with the increase of rainfall intensity. The results can provide a theoretical reference for the establishment of soil erosion prediction model and the formulation of soil and water conservation measures.