雨强对华北土石山区坡面侵蚀及其颗粒富集过程的影响

发布时间：2018-04-29 19:19

本文选题：人工模拟降雨 + 华北土石山区　；参考：《水土保持学报》2017年04期

【摘要】：为研究雨强对华北土石山区坡面侵蚀过程和泥沙颗粒分布规律的影响,采用室内人工模拟降雨试验,以华北土石山区2种典型土壤为研究对象,在4种雨强(30,60,90,120mm/h)条件下,分析了径流的变化过程和侵蚀泥沙的颗粒组成及其颗粒富集率的变化规律。结果表明:(1)随着雨强从30mm/h增大至120mm/h,黄土性褐土和石灰性褐土的产流时间均逐渐减小,分别缩短了79%和85%;(2)在60,90,120mm/h雨强条件下,黄土性褐土的径流强度和泥沙浓度均随降雨时间先减小后增大,而后趋于稳定状态,石灰性褐土仅在120mm/h雨强条件下出现相似规律;(3)当雨强从30mm/h增大至120mm/h,黄土性褐土泥沙流失朝粗颗粒化发展,侵蚀泥沙的砂粒和粗粉粒含量分别增加了86%和21%,而石灰性褐土的变化不明显;(4)在降雨初始阶段,粒径较小的黏粒和细粉粒明显富集,而粒径较大的粗粉粒和砂粒不易流失,但随着降雨历时的延长,不同粒径泥沙颗粒的富集率趋于1,这种现象在大雨强下表现得尤为明显。
[Abstract]:In order to study the influence of rain intensity on erosion process and sediment particle distribution in slope surface of North China earth-rock mountain area, two typical soils in North China earth-rock mountain area were studied by artificial simulated rainfall experiment in laboratory, under the condition of four kinds of rain intensity of 3060,90120mm / h. The variation process of runoff, the particle composition of erosion sediment and the variation law of particle enrichment rate are analyzed. The results showed that with the increase of rain intensity from 30mm/h to 120mm / h, the runoff production time of both loess cinnamon soil and calcareous cinnamon soil decreased by 79% and 85% respectively.) under the condition of 60 ~ 90120mm / h rain intensity, the runoff production time of loess cinnamon soil and calcareous cinnamon soil decreased gradually. The runoff intensity and sediment concentration of loess cinnamon soil decrease firstly and then increase with rainfall time, and then tend to stable state. Calcareous cinnamon soil has a similar rule only under the condition of 120mm/h rain intensity. When the rainfall intensity increases from 30mm/h to 120 mm / h, the sediment loss of loess cinnamon soil develops towards coarse granulation. The content of sand and coarse silt increased by 86% and 21%, respectively, but the change of calcareous cinnamon soil was not obvious. However, with the extension of rainfall duration, the enrichment rate of sediment particles with different particle sizes tends to be 1, which is especially evident in heavy rain.
【作者单位】：北京林业大学水土保持学院北京林业大学水土保持与荒漠化防治教育部重点试验室;
【基金】：华北土石山区防护林体系景观格局调控与空间配置技术研究项目(2015BAD07B030201)
【分类号】：S157.1

【相似文献】