Effects of wet meadow riparian vegetation on streambank erosion. 2. Measurements of vegetated bank strength and consequences for failure mechanics
Effects of wet meadow riparian vegetation on streambank erosion. 2. Measurements of vegetated bank strength and consequences for failure mechanics
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DOI：
10.1002/esp.340
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发表时间：
2002-07-01
影响因子：
3.3
通讯作者：
Kirchner, JW
中科院分区：
文献类型：
--
作者：
Micheli, ER;Kirchner, JW
我们测量了潮湿草甸植被对一个蜿蜒的山地草甸流，南叉的克恩河在莫纳奇草甸，在加州的塞拉利昂内华达州的银行强度和故障力学的影响。河岸殖民地的“湿”禾本科草甸植被的平均5倍强于那些殖民地的“干旱草甸和灌丛植被。我们的测量结果表明，强度与植被密度指标，包括茎数，单位面积的生物量，根质量与土壤质量的比率。灯心草在稳定粗沙洲表面方面似乎比莎草更好，而莎草在稳定活跃侵蚀的切割河岸方面更有效。潮湿的草甸洪泛区植被产生了复合切割河岸配置（覆盖在无粘性材料上的粘性层），通过悬臂破坏而侵蚀。悬臂稳定性的现场测量和岩土模型表明，通过增加河岸强度，潮湿的草甸植被增加了河岸悬臂的厚度、宽度和粘性，这反过来又增加了破坏所需的时间。分离，并删除银行故障块。在Monache Meadow，需要大约四年的时间来生产和移除1米宽的湿草地堤岸。湿草甸植被通过增加河岸强度来限制河岸迁移速率。改变崩岸模式，降低崩岸频率。版权所有（C）2002约翰威利父子有限公司
We measured the effect of wet meadow vegetation on the bank strength and failure mechanics of a meandering montane meadow stream, the South Fork of the Kern River at Monache Meadow, in California's Sierra Nevada. Streambanks colonized by 'wet' graminoid meadow vegetation were on average five times stronger than those colonized by 'dry xeric meadow and scrub vegetation. Our measurements show that strength is correlated with vegetation density indicators, including stem counts, standing biomass per unit area, and the ratio of root mass to soil mass. Rushes appear better than sedges at stabilizing coarse bar surface, while sedges are far more effective at stabilizing actively eroding cut banks.Wet meadow floodplain vegetation creates a composite cut bank configuration (a cohesive layer overlying cohesionless materials) that erodes via cantilever failure. Field measurements and a geotechnical model of cantilever stability show that by increasing bank strength, wet meadow vegetation increases the thickness, width, and cohesiveness of a bank cantilever, which, in turn, increases the amount of time required to undermine. detach, and remove bank failure blocks. At Monache Meadow, it takes approximately four years to produce and remove a 1 m wide wet meadow bank block. Wet meadow vegetation limits bank migration rates by increasing bank strength. altering bank failure modes, and reducing bank failure frequency. Copyright (C) 2002 John Wiley Sons, Ltd.