两种工程堆积体边坡模拟径流侵蚀对比研究

发布时间：2018-03-28 01:41

本文选题：产流产沙　切入点：入渗　出处：《土壤学报》2017年03期

【摘要】：基于对重庆市城镇建设中工程堆积体野外调查结果,选择广泛存在的紫色土和黄沙壤工程堆积体为研究对象,采用野外实地放水冲刷试验,对比分析了不同土石比及坡度的工程堆积体边坡径流侵蚀过程。结果表明:(1)工程堆积体土壤入渗率随冲刷过程呈先快速减小、后逐渐稳定的变化趋势,且波动幅度大小随冲刷流量的不同出现差异,下垫面稳定入渗率均在0.4~1.7 mm min~(-1)之间。(2)不同下垫面堆积体产流率随冲刷时间均呈先增加后稳定的谷峰交织变化趋势且随放水流量增大而显著增强;在相同放水流量时,黄沙壤堆积体平均产流率最大可为紫色土堆积体的1.89倍。(3)不同下垫面堆积体径流含沙量随冲刷时间呈先增加后稳定的波动趋势;径流含沙量在不同流量条件下介于0.21~1278.49 g L~(-1);冲刷过程中坡面面蚀向沟蚀的转化对径流含沙量有显著影响,最大可增加13.73倍;堆积体坡面侵蚀过程存在突变期、活跃期和稳定期3个阶段,细沟发生的偶然性和随机性对产沙量波动贡献率最大。(4)工程堆积体在不同放水流量条件下侵蚀泥沙颗粒粒径分布差异性明显,紫色土堆积体最大侵蚀泥沙颗粒均大于黄沙壤堆积体。研究结果可为重庆市城镇建设工程堆积体新增水土流失量预测和植被生态恢复提供重要科学依据。
[Abstract]:Based on the field investigation results of engineering accumulations in urban construction in Chongqing, the widely existing engineering accumulations of purple soil and yellow sand soil were selected as the research objects, and field field flushing experiments were carried out. The runoff erosion process of engineering accumulative slope with different ratio of soil to rock and slope is analyzed. The results show that the infiltration rate of engineering accumulation body decreases rapidly with the erosion process, and then changes steadily. And the amplitude of fluctuation varies with the scour flow. The steady infiltration rate of the underlying surface is between 0.4 ~ 1.7 mm / min ~ (-1).) the runoff yield of the accumulative body on the underlying surface increases first and then increases steadily with the erosion time, and increases significantly with the increase of the discharge rate, and at the same discharge rate, the flow rate of the accumulative body on the underlying surface increases significantly with the increase of the water discharge rate. The average runoff yield of yellow sandy soil is 1.89 times that of purple soil. The sediment content of runoff is between 0.21 ~ 1278.49 g / L ~ (-1) ~ (-1) under different discharge conditions, and the transformation of slope surface erosion to trench erosion has a significant effect on runoff sediment content, and the maximum increase is 13.73 times. In the three stages of active and stable stages, the probability and randomness of the occurrence of the rill has the largest contribution to the fluctuation of sediment yield. 4) the particle size distribution of the eroded sediment particles in the engineering accumulations is different under different discharge conditions. The maximum eroded sediment particles in purple soil are larger than those in yellow sand soil. The results can provide important scientific basis for the prediction of new soil erosion and vegetation ecological restoration in urban construction engineering in Chongqing.
【作者单位】：西南大学资源环境学院西南大学水土保持生态环境研究所;重庆市水土保持生态环境监测总站;重庆市水利电力勘测设计研究院;
【基金】：重庆市水利局科技项目"生产建设项目工程堆积体水土流失规律研究(ZXKJXM 001286)" "重庆市生产建设项目水土流失危害研究(ZXKJXM 002825)"资助~~
【分类号】：S157.1

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