黄土堆积体植物篱减沙效益与泥沙颗粒分形特征研究

发布时间：2018-04-05 23:37

本文选题：工程堆积体　切入点：植物篱　出处：《农业机械学报》2017年08期

【摘要】：为探究植物篱措施对工程堆积体边坡的减流减沙效益及其对侵蚀泥沙颗粒分形维数的影响,以堆积体未防护边坡为对照,以不同放水流量对不同坡度堆积体植物篱防护边坡进行了放水冲刷试验。结果表明:与对照相比,植物篱边坡初始产流时间滞后100~500 s,其产流率、产沙率整体均较小,产流率在时间尺度上表现为间歇性波动上升;植物篱减流效率在4%~60%之间,减沙效率范围在15%~50%之间,减流减沙效率均随坡度和放水流量的增加呈幂函数形式减小;各处理侵蚀泥沙颗粒中粉粒均占主导地位,黏粒次之,砂粒含量最少。与对照小区相比,植物篱防护边坡侵蚀泥沙砂粒体积分数降低,黏粒和粉粒体积分数升高;黏粒富集率增加,砂粒富集率减小,泥沙颗粒分形维数增大。分形维数与黏粒和砂粒体积分数之间均呈极显著线性相关,侵蚀泥沙颗粒分形维数主要由黏粒体积分数决定。
[Abstract]:In order to explore the effect of hedgerow measures on the flow and sediment reduction benefits and the fractal dimension of erosive sediment particles, the effect of hedgerow measures on the flow and sediment reduction and the fractal dimension of erosive sediment particles were investigated, and the unprotected slope was used as a control.The flushing scour test of hedgerow slope with different slope was carried out with different discharge flow.The results showed that, compared with the control, the initial runoff production time of hedgerow slope was 100 ~ 500 s, the runoff yield and sediment yield were smaller, the runoff yield increased intermittently on the time scale, and the efficiency of hedgerow flow reduction was between 4 ~ 60%.The range of sediment reduction efficiency is between 15% and 50%, and the efficiency of flow reduction and sediment reduction decreases with the increase of slope and water discharge, and silt plays a dominant role in the sediment particles of each treatment, followed by clay, and the content of sand is the least.Compared with the control plot, the volume fraction of erosion sand decreased, the volume fraction of clay and silt increased, the enrichment rate of clay increased, the enrichment rate of sand decreased, and the fractal dimension of sediment particles increased.The fractal dimension is linearly correlated with the volume fraction of clay and sand, and the fractal dimension of erosive sediment is mainly determined by the volume fraction of clay.
【作者单位】：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;中国科学院大学;西北农林科技大学水土保持研究所;
【基金】：国家自然科学基金项目(41671283)
【分类号】：S157

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