scholarly journals Flood Protection and River Ecosystem Restoration through River Widening: Focusing on European River Restoration Cases

2010 ◽  
Vol 64 (null) ◽  
pp. 127-148
Author(s):  
권태정 ◽  
심우배
2021 ◽  
pp. 117538
Author(s):  
Jiahui Shang ◽  
Wenlong Zhang ◽  
Xinqi Chen ◽  
Yi Li ◽  
Lihua Niu ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isabella Schalko ◽  
Ellen Wohl ◽  
Heidi M. Nepf

AbstractWood is an integral part of a river ecosystem and the number of restoration projects using log placements is increasing. Physical model tests were used to explore how the wood position and submergence level (discharge) affect wake structure, and hence the resulting habitat. We observed a von-Kármán vortex street (VS) for emergent logs placed at the channel center, while no VS formed for submerged logs, because the flow entering the wake from above the log (sweeping flow) inhibited VS formation. As a result, emergent logs placed at the channel center resulted in ten times higher turbulent kinetic energy compared to submerged logs. In addition, both spatial variation in time-mean velocity and turbulence level increased with increasing log length and decreasing submergence level. Submerged logs and logs placed at the channel side created a greater velocity deficit and a longer recirculation zone, both of which can increase the residence time in the wake and deposition of organic matter and nutrients. The results demonstrate that variation in log size and degree of submergence can be used as a tool to vary habitat suitability for different fish preferences. To maximize habitat diversity in rivers, we suggest a diverse large wood placement.


2013 ◽  
Vol 726-731 ◽  
pp. 1764-1769
Author(s):  
Qing Feng Chen ◽  
Hong Yan Yang ◽  
Jun Jian Ma ◽  
Wen Guo Dong ◽  
Meng Liu

The traditional water treatment technologies mainly include physical reparation technology, chemical remediation technology and biological-ecological restoration technology. However, there are many limitations in practical application, especially for heavy polluted river. For this reason, it is extremely urgent to explore new technology and method on river ecosystem restoration. The materials of artificial plants are limited to the factors of water transparency, possesses acid and alkali-resistant, resistance to staining and flexibility. The characteristics of artificial plants are low in investment, effective and no secondary pollution. Therefore, it has a broad prospect of application in water treatment. In this paper, the detailed review and application of artificial plants were involved in order to provide theoretical basis for more widely used of artificial aquatic plants.


2009 ◽  
Vol 60 (9) ◽  
pp. 976 ◽  
Author(s):  
Tamao Kasahara ◽  
Thibault Datry ◽  
Michael Mutz ◽  
Andrew J. Boulton

Many river restoration projects seek to address issues associated with impaired hydrological and ecological connectivity in longitudinal (e.g. effects of dams, weirs) or lateral (e.g. alienated floodplain) dimensions. Efforts to restore the vertical dimension of impaired stream–groundwater exchange are rare, hampered by limited understanding of the factors controlling this linkage in natural alluvial rivers. We propose a simplified two-axis model of the ‘primary drivers’ (sediment structure and vertical hydraulic gradient) of stream–groundwater exchange that acknowledges their interaction and provides a practical template to help researchers and river managers pose hypothesis-driven solutions to restoration of damaged or lost vertical connectivity. Many human activities impact on one or both of these drivers, and we review some of the tools available for treating the causes (rather than symptoms) in impacted stream reaches. For example, creating riffle-pool sequences along stream reaches will enhance vertical hydraulic gradient, whereas flushing flows can remove clogging layers and sustain sediment permeability. Our model is a first step to specifying mechanisms for recovery of lost vertical connectivity. Assessing results of river restoration using this approach at reach to catchment scales will provide scientific insights into the interplay of hydrology, fluvial geomorphology and river ecosystem function at appropriately broad scales.


2019 ◽  
Vol 11 (1) ◽  
pp. 76-100
Author(s):  
Allen Bellas ◽  
Lea Kosnik

AbstractIn 1992, Congress passed The Elwha River Ecosystem and Fisheries Restoration Act with the goal of “full restoration of The Elwha River Ecosystem and native anadromous fisheries.” As part of that act, the federal government was required to produce a benefit-cost analysis on dam removal of the Elwha and Glines Canyon dams, which was published in 1994. This article revisits that initial 1994 benefit-cost analysis; background on its methods and assumptions is given, comparisons are made to current state-of-the-art techniques in benefit-cost analysis, and an ex post benefit-cost analysis of the project is conducted for comparison purposes. We find that the cost and scope of the project exceeded original expectations, the cost of the foregone electricity generation was less than expected, and that anticipated recreational and fisheries benefits were both delayed, and lower, than expected. Furthermore, issues such as the value of hatchery-spawned versus wild anadromous fish seem not to have been anticipated in the original analysis, highlighting the fact that in doing an ex ante analysis, researchers must expect that unexpected factors may influence the ex post results of any project.


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