坡面覆沙后侵蚀泥沙颗粒分选特性

发布时间：2018-06-22 14:41

本文选题：侵蚀 + 颗粒大小　；参考：《农业工程学报》2017年02期

【摘要】：侵蚀泥沙颗粒大小的分布在一定程度上影响着侵蚀泥沙的搬运和沉积,了解侵蚀泥沙的分选作用将有助于解释泥沙的侵蚀和沉积过程。该文以覆沙坡面为研究对象,采用室内模拟降雨的方法,选取坡度12°、雨强1.5 mm/min的黄土坡面上分别覆盖0.5、1.0、1.5 cm的沙层进行试验。结果表明:坡面覆沙后,坡面粗颗粒物质大部分在产流开始0~10 min内便被冲刷带走;侵蚀泥沙颗粒主要以粉粒为主;坡面覆沙后,在细沟间侵蚀阶段,径流优先搬运大于0.054 mm的颗粒,在细沟侵蚀阶段和细沟侵蚀及细沟间侵蚀的组合阶段,径流搬运的泥沙颗粒以小于0.054 mm的颗粒为主;同时,在产流前期(0~10 min)侵蚀泥沙颗粒主要以大于0.054 mm的颗粒为主;而在产流后期(10 min以后)侵蚀泥沙则主要以小于0.054 mm的颗粒为主。坡面覆沙后,黏粒以团聚体的形式存在,粉粒以单粒的形式存在,而沙粒以细颗粒聚集体的形式存在。该文为进一步研究泥沙沉积后风蚀对水蚀的影响提供数据支撑。
[Abstract]:The distribution of erosion sediment particle size to some extent affects the transport and deposition of erosive sediment. Understanding the separation of erosive sediment will help to explain the process of erosion and deposition. In this paper, taking the covered slope as the research object, using the method of indoor rainfall simulation, the loess slope surface with 12 掳slope and 1.5 mm/min rainfall intensity is selected to cover the sand layer of 0.5 ~ 1.0 ~ 1.5 cm respectively, and the experiment is carried out on the loess slope with a gradient of 12 掳and a rainfall intensity of 1. 5 mm/min. The results showed that most of the coarse grain material was washed away within 10 min from the beginning of runoff generation, and the sediment particles were mainly silt particles, and the sediment particles were mainly silt particles during the erosion stage of the gully after the sand covering on the slope surface. In the rill erosion stage and the combination stage of rill erosion and rill erosion, sediment particles less than 0.054 mm are the main sediment particles transported by runoff. In the early stage of runoff (0 ~ 10 min), the main eroded sediment particles were larger than 0.054 mm, while in the late stage of runoff (10 min after 10 min), the main eroded sediment particles were less than 0.054 mm. When the slope is covered with sand, the clay exists in the form of aggregates, the silt in the form of single particles, and the sand in the form of fine aggregates. This paper provides data support for further study on the effect of wind erosion on water erosion after sediment deposition.
【作者单位】：西安理工大学西北水资源与环境生态教育部重点实验室;中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;
【基金】：国家自然科学基金青年项目(41401305);国家自然科学基金重点项目(41330858) 西安理工大学博士创新基金(310-252071505)
【分类号】：S157.1

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