返回
Assessing Riverbed Surface Destabilization Risk Downstream Isolated Vegetation Elements
DOI:10.3390/w14182880.png)
摘要
En 中文
A few decades ago, river erosion protective approaches were widely implemented, such as straightening the river course, enhancing riverbed/bank stability with layers of concrete or riprap, and increasing channel conveyance capacity (i.e., overwidening). However, recent research has established that such practices can be tremendously costly and adversely affect the rivers' ecological health. To alleviate these effects, green river restoration has emerged as a sustainable and environmentally friendly approach that can reduce the negative impact of the riverbed and bank destabilization and flooding. One of the typical green restoration measures, especially for instream habitat improvement, is the establishment of instream vegetation, which leads to a more diversified flow regime, increasing habitat availability and serving as refugia for aquatic species. Within the perspective presented above, flow-vegetation interaction problems for several decades received significant attention. In these studies, rigid rods have commonly been used to simulate these vegetative roughness elements without directly assessing the riverbed destabilization potential. Here, an experimental study is carried out to investigate the effect of different instream vegetation porosity on the near-bed flow hydrodynamics and riverbed destabilization potential for a range of simulated vegetation species. Specifically, the flow field downstream, four distinct simulated vegetation elements is recorded using an acoustic Doppler velocimetry (ADV), assuming about the same solid volume fraction for the different vegetation elements. In addition, bed destabilization potential is assessed by recording with optical means (a He-Ne laser with a camera system) the entrainment rate of a 15 mm particle resting on the uniform bed surface and the number of impulses above a critical value. Results revealed that the number of impulses above a critical value at the normalized distance equal to two is a good indicator for cylinder and five for other vegetation to assess the riverbed destabilization potential. The experimental findings from this study have interesting geomorphological implications regarding the destabilization of the riverbed surface (removal of coarse particles induced by high magnitude turbulent impulses) and the successful establishment of seedlings downstream of instream vegetation.
Keyword:
instream vegetation
entrainment rate
coarse sediment
flow turbulence
impulse
sensors
instrumentation
期刊
W
IF:
3
论文数:
3.2W
被引数:
7.4W
机构
引用论文
Awareness, Knowledge, and Preferences of United States (US) Patients with Chronic Lymphocytic Leukemia (CLL) and Their Caregivers Related to Finite Duration (FD) Therapy and Minimal (Measurable) Residual Disease (MRD)美国(US)慢性淋巴细胞白血病(CLL)患者及其照护者对有限疗程(FD)治疗和微小(可测量)残留病灶(MRD)的认知、知识和偏好
Blood
IF0
Decreased in situ expression of interleukin-10 receptor is correlated with the exacerbated inffammatory and cytotoxic responses observed in mucosal leishmaniasis.局部白介素-10受体表达的下调与黏膜利什曼病中观察到的加剧的炎症和细胞毒性反应相关。

