文献类型： 外文期刊

第一作者： Su Zheng-an

作者： Su Zheng-an;He Zhou-yao;Zhou Tao;Wang Jun-jie;Wang Xiao-yi;Wang Li-juan;Liu Yi-han;Wu Zuo;He Zhou-yao;Zhou Tao;Wang Jun-jie;Wang Li-juan;Wang Xiao-yi;Wu Zuo;Fang Hai-dong;Shi Liang-tao;Liu Yi-han

作者机构：

关键词： Soil erosion; Indigenous grass species; Bank gully; Concentrated flows; Flow energy consumption; Dry and hot valley

期刊名称：JOURNAL OF MOUNTAIN SCIENCE （ 影响因子：1.55； 五年影响因子：1.651 ）

ISSN： 1672-6316

年卷期： 2021 年 18 卷 4 期

页码：

收录情况： SCI

摘要： To quantify the impacts of native vegetation on the spatial and temporal variations in hydraulic properties of bank gully concentrated flows, a series of in situ flume experiments in the bank gully were performed at the Yuanmou Gully Erosion and Collapse Experimental Station in the dry-hot valley region of the Jinsha River, Southwest China. This experiment involved upstream catchment areas with one- and two-year native grass (Heteropogon contortus) and bare land drained to bare gully headcuts, i.e., Gullies 1, 2 and 3. In Gully 4, Heteropogon contortus and Agave sisalana were planted in the upstream catchment area and gully bed, respectively. Among these experiments, the sediment concentration in runoff in Gully 3 was the highest and that in Gully 2 was the lowest, clearly indicating that the sediment concentration in runoff obviously decreased and the deposition of sediment obviously increased as the vegetation cover increased. The concentrated flows were turbulent in response to the flow discharge. The concentrated flows in the gully zones with native grass and bare land were sub- and supercritical, respectively. The flow rate and shear stress in Gully 3 upstream catchment area were highest among the four upstream catchment areas, while the flow rate and shear stress in the gully bed of Gully 4 were lowest among the four gully beds, indicating that native grass notably decreased the bank gully flow rate and shear stress. The Darcy-Weisbach friction factor (resistance f) and flow energy consumption in the gully bed of Gully 4 were notably higher than those in the other three gully beds, clearly indicating that native grass increased the bank gully surface resistance and flow energy consumption. The Reynolds number (Re), flow rate, shear stress, resistance f, and flow energy consumption in the gully beds and upstream areas increased over time, while the sediment concentration in runoff and Froude number (Fr) decreased. Overall, increasing vegetation cover in upstream catchment areas and downstream gully beds of the bank gully is essential for gully erosion mitigation.

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