Effects of riparian plant roots on the unconsolidated bank stability of meandering channels in the Tarim River, China
Effects of riparian plant roots on the unconsolidated bank stability of meandering channels in the Tarim River, China
复制标题
河岸植物根系对塔里木河曲流河道松散河岸稳定性的影响
DOI：
10.1016/j.geomorph.2019.106958
复制
发表时间：
2020-02
期刊：
影响因子：
3.9
通讯作者：
Yi Yujun
中科院分区：
文献类型：
--
作者：
Yu Guo-An;Li Zhiwei;Yang Hanyuan;Lu Jianyin;Huang He Qing;Yi Yujun
中国西北部塔里木河中下游发育曲折、扭曲的曲折河道。由松散材料组成的河岸强度低得多，特别是在高流量条件下，容易受到河流侵蚀和堤岸坍塌的影响。因此，在这样的环境中曲折的形成和发展似乎是不直观的。在没有粘性沉积物的情况下，推测河岸植物根系对岸坡稳定性和弯道发育有显著影响是合乎逻辑的，但这一点尚未得到证实。为确定根系凝聚力对塔里木河曲流河河道岸坡稳定性的影响，对塔里木河曲流河弯道上局部优势河岸植被胡杨(PE)、多枝柳(Trarix Ramosis Sima)和芦荟(Phrigmites Australis)的根系进行了现场测量和取样，得到了直径和根面积比等根系参数。利用遥感图像计算了与采样点对应的局部弯曲曲率半径。利用岸坡稳定性和坡脚侵蚀模型(BSTEM)，定量估计了不同根系条件对河道岸坡强度的影响。结果表明，树根(和砂根复合材料)对松散岸坡起到了有效的加固作用，控制了岸坡的侵蚀，从而提高了岸坡的稳定性。然而，在不同的根系条件下，影响是高度不同的。PA根对岸坡强度的改善作用普遍大于PE和TP，PA、PE和TP对岸坡强度的改善幅度分别为88.2%、73.2%和63.6%。因此，在这种极端干旱和松散的沉积物环境中的河岸植被似乎是维持曲折河道的先决条件。
Meandering channels with highly sinuous and distorted bends have developed along the middle and lower reaches of the Tarim River in northwestern China. Riverbanks composed of unconsolidated materials have much lower bank strengths and are susceptible to fluvial erosion and bank collapse, particularly under high flow conditions. Thus, the formation and development of meander bends in such environments appear unintuitive. It is logical to speculate that riparian plant roots in unconsolidated banks have significant effects on bank stability and bend development in the absence of cohesive sediments, but this has not been verified. To determine the influence of root cohesion on the bank stability of meandering channels in the Tarim River, in situ measurements and sampling of roots from locally dominant riparian vegetation, i.e.,Populus euphratica(PE),Tamarix ramosissima(TR), andPhragmites australis(PA), were conducted on the meandering bends to obtain root parameters, including diameter and root area ratio. The radius of curvature of local bends corresponding to sampling sites was also calculated using remote sensing imagery. We used the Bank Stability and Toe Erosion Model (BSTEM) to quantitatively estimate the effects of different root conditions on channel bank strength. The results confirmed that roots (and sand–root composites) provide effective reinforcement to unconsolidated banks, control the bank erosion, and hence enhance bank stability. However, the effects were highly variable under different root conditions. PA roots generally improved bank strength more than those of PE or TR, with PA, PE, and TR improving bank strength by 88.2%, 73.2%, and 63.6%, respectively. Riparian vegetation in this extremely arid and unconsolidated sediment environment therefore appears to be a prerequisite for sustaining the meandering channel.
登录
查看更多内容
影响因子：
5.4
作者：
W. M. Dijk;R. Teske;W. Lageweg;M. Kleinhans
通讯作者：
W. M. Dijk;R. Teske;W. Lageweg;M. Kleinhans
影响因子：
3.9
作者：
N. Pollen-Bankhead;A. Simon
通讯作者：
N. Pollen-Bankhead;A. Simon
影响因子：
4.6
作者：
Xia J;Deng S;Lu J;Xu Q;Zong Q;Tan G
通讯作者：
Tan G
影响因子：
3.9
作者：
Zhiwei Li;Guoan Yu;G. Brierley;Zhaoyin Wang;Y. Jia
通讯作者：
Zhiwei Li;Guoan Yu;G. Brierley;Zhaoyin Wang;Y. Jia
影响因子：
3.3
作者：
M. Tal;C. Paola
通讯作者：
M. Tal;C. Paola