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Evaluating the concrete grade-control structures built by modified fish-nest bricks in the river restoration: A
Jianhua Liu1, Zhonghua Yang1, Ming Li2
1State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, China.
Journal of Environmental Management
|April 23, 2022
Summary
New indicators evaluate concrete grade-control structures (CGCSs) for river restoration. Staggered CGCSs improve riverbed protection and fish habitats by increasing flow diversity and sweep events.
Area of Science:
- River engineering
- Environmental fluid mechanics
- Ecological restoration
Background:
- Concrete grade-control structures (CGCSs) are vital for large river restoration.
- A lack of laboratory-based evaluation indicators for CGCSs hinders research.
- Assessing CGCS impacts on geomorphology and fish habitats is crucial.
Purpose of the Study:
- To propose and validate novel indicators for evaluating CGCSs in laboratory settings.
- To assess the geomorphological and fish habitat impacts of CGCSs.
- To provide a theoretical basis for CGCS application in river restoration.
Main Methods:
- Conducted flume experiments with CGCSs made of modified fish-nest bricks.
- Varied Reynolds number and structural layout conditions.
- Analyzed flow field data (streamwise, transverse, vertical) using quadrant analysis and Shannon's entropy.
Main Results:
- Identified large recirculation zones around CGCS elements.
- Quantified suspended sediment deposition mechanisms through sweep and ejection analysis.
- Observed higher spatial-averaged sweep event probability and flow diversity with staggered CGCS arrays.
Conclusions:
- Staggered CGCS arrangements enhance riverbed protection and fish habitat suitability.
- The proposed indicators (spatial-averaged sweep probability and flow diversity) effectively predict CGCS performance.
- This research offers a scientific foundation for utilizing CGCSs in river restoration projects.
Keywords:
Evaluation indicatorsFlow diversityModified fish-nest bricksRiver restorationSediment transportMore Related Videos
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