淤地坝对黄土浅层滑坡的减蚀作用  

The Erosion Reduction Effect of Check Dam on Loess Landslide

作　　者：张霞[1] 于国强[2] 李鹏[1] 李占斌[1] ZHANG Xia;YU Guoqiang;LI Peng;LI Zhanbin(State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048;Key Laboratory of Groundwater and Ecology in Arid and Semi-arid Areas,Xi’an Center of Geological Survey,China Geological Survey,Xi’an 710054)

机构地区：[1]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048 [2]中国地质调查局干旱-半干旱区地下水与生态重点实验室,西安710054

出　　处：《水土保持学报》2022年第5期51-57,共7页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(42177346,52009103);陕西省创新能力支撑计划项目(2019TD-040);陕西省重点研发计划项目(2021ZDLSF05-01)。

摘　　要：为了研究淤地坝淤积对浅层滑坡的减蚀作用,基于三维连续介质动态数值模型,采用Voellmy流变模型,分析了侵蚀基准面抬升后黄土滑坡运动参数、动力参数以及能量参数的变化规律。结果表明:浅层滑坡在沟谷坡运动过程中,平均速度、前缘速度、侵蚀物质体积和总动能急剧增加,导致滑坡在接触坡脚时前缘速度出现波动且坡脚处侵蚀严重,极具破坏性。随着侵蚀基准面逐渐抬升,滑坡运行时间和平均速度峰值呈“S”形函数下降趋势,前缘速度和滑坡移动距离呈线性函数下降趋势,侵蚀物质体积和总动能呈指数函数下降趋势。随着侵蚀基准面逐渐抬升,滑坡的运动空间和侵蚀空间逐渐减少,仅在一定程度上降低了滑坡速度,但却有效抑制了滑坡的侵蚀作用,使侵蚀物质质量急剧减少,从而有效减少了滑坡体侵蚀总动能,在很大程度上减轻了浅层滑坡的致灾强度和致灾规模。研究结果揭示了淤地坝可以通过抬升侵蚀基准面来减少侵蚀,有助于加深淤地坝对黄土浅层滑坡减蚀作用机理的理解。To study the erosion reduction effect of a check dam on the landslide, the variation of motion parameters, dynamic parameters, and energy parameters of loess landslide with the rising elevation of the erosion base level were analyzed by Voellmy model based on three-dimensional continuum model. The results showed that the mean velocity, frontal velocity, erosion volume, and total kinetic energy of the landslide masses all increased sharply during the gully-slope motion. As a result, the frontal velocity fluctuated and severely eroded at the slope’s foot, which was extremely destructive. Landslide running time and mean velocity varied within the sigmoidal function distribution range, frontal velocity and landslide moving distance varied within the linear function distribution range, and erosion mass volume and total kinetic energy varied within the exponential function distribution range with the rising elevation of the erosion base level. The motion space and erosion space of the landslide were gradually reduced, which only reduced the landslide velocity to a certain extent, but it could effectively inhibit the erosion effect of the landslide and sharply reduce the mass of eroded materials, thereby effectively reduced the total kinetic energy of the landslide, and reduced the disaster intensity largely with the rising elevation of the erosion base level. The information indicated that the check dam could reduce erosion by the rising elevation of the erosion base level, and the results could be useful for better understanding the erosion reduction mechanisms of a check dam on loess landslide.

关 键 词：黄土高原 淤地坝 沟谷坡 侵蚀能量 减蚀作用 

分 类 号：S157.1[农业科学—土壤学]