生草覆盖条件下不同降雨强度对紫色土坡面侵蚀产沙的影响

造林种草,增加植被覆盖度是防止土壤侵蚀的重要措施.通过人工模拟降雨试验,探讨生草覆盖下紫色土坡面侵蚀产沙的动态变化.结果表明,有生草覆盖的坡面径流含沙量较裸地的径流含沙量更快达到稳定状态;坡面侵蚀产沙率随覆盖度增加呈指数型递减,且坡下种草的减沙效果最好;覆盖度与降雨强度对坡面侵蚀产沙量的影响存在对比消长关系,但生草覆盖度对产沙量的影响小于降雨强度的变化对产沙量的影响.

Effects of grass coverage pattern and rainfall intensity on soil loss in purple soil slopeland

Increasing the vegetation coverage by afforestation and grass planting is one of the most impor-tant measures to prevent and control soil erosion. In this paper,we use artificial rainfall simulation experi-ment to study the effects of different grass coverage patterns and rainfall intensity on soil loss in purple soil slopeland. The results show that the runoff sediment concentration of the slopeland with grass coverage is easier to reach a steady state than in bare land. Moreover,erosion and sediment yield rate decreases expo-nentially with the increase of grass coverage and the best effect is observed when grass covers the lower part of the slope. The rainfall intensity and coverage rate have contrasting influences on the total sediment yield,with the former playing a more significant role in sediment production.