覆沙坡面水动力学参数与径流产沙的关系

发布时间：2018-03-21 22:15

本文选题：侵蚀　切入点：径流　出处：《农业工程学报》2017年20期 　论文类型：期刊论文

【摘要】：坡面流水动学特征对阐明土壤侵蚀和坡面产沙机理均有重要意义,通过模拟降雨试验,定量研究了1.5 mm/min雨强下,不同覆沙厚度(0.5、1.0、1.5 cm)下坡面水动力学参数的时空分布特征及其与产流产沙的关系,以期揭示坡面水动力学参数的内在规律性。结果表明,坡面流的水动力学参数的时空分布呈波动趋势,与黄土坡面相比,雷诺数增加了0.39~1.03倍,佛罗德数增加了0.05~0.29倍,阻力系数增加了0.05~1.55倍;覆沙坡面在整个降雨过程中主要以层流—急流为主,细沟形成主要发生在产流后第10 min后,主要集中在1~10断面处(从坡底依次向上每1 m划分为一个断面);坡面产流和产沙速率与各水动力学参数均可用y=ax+b来描述,雷诺数Re和相对水深曼宁糙率n/h可以较好地表征覆沙坡面侵蚀产沙过程。此研究可为坡面侵蚀预报模型的构建提供科学依据。
[Abstract]:The dynamic characteristics of income on slope surface are of great significance to clarify the mechanism of soil erosion and sediment yield on slope surface. The simulated rainfall experiment is used to quantitatively study the rainfall intensity of 1. 5 mm/min. The spatial and temporal distribution characteristics of hydrodynamic parameters and the relationship between hydrodynamic parameters and sediment yield under different sediment cover thickness of 0.5 ~ 1.0 ~ 1.5 cm were discussed in order to reveal the inherent regularity of hydrodynamic parameters on slope surface. Compared with the loess slope surface, the Reynolds number increased by 0.39 ~ 1.03 times, the Frod number increased by 0.05 ~ 0.29 times, and the resistance coefficient increased by 0.05 ~ 1.55 times. During the whole rainfall process, laminar flow and jet flow dominated the slope, and the formation of rill occurred 10 min after runoff production. It is mainly concentrated at section 1 / 10 (divided into one section per 1 m in turn from the bottom of the slope), and the runoff and sediment yield rate and hydrodynamic parameters of the slope can be described by y=ax b. The Reynolds number re and the relative depth of Manning roughness n / h can better characterize the process of erosion and sediment yield on the sandy overlying slope, which can provide a scientific basis for the construction of prediction model of slope erosion.
【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】：国家重点研究与发展项目(2016YFC0402404) 国家自然科学基金青年项目(41401305,41601291);国家自然科学基金重点项目(41330858) 陕西省自然科学基础研究计划项目(2016JM4017) 西安理工大学博士创新基金(310-252071505,310-252071506)
【分类号】：S157.1

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