Oyster reefs as alternatives to mitigate coastal erosion: A study of hydrodynamics and sediment transport around oyster castles

Coastal erosion is a significant challenge to communities worldwide, prompting increasing interest in nature-based solutions as alternatives to traditional hard engineering structures. Oyster reefs are ecologically relevant assets that can be restored using living oyster castles, offering a potential approach for coastal protection. As part of the research for this thesis, experiments were carried out in a wave flume at the Environmental Fluid Mechanics Laboratory (EFML) at the University of Illinois in Urbana-Champaign (UIUC). Experiments were designed to study the impact of interlocking oyster castles on flow hydrodynamics and sediment transport. Using two-dimensional particle image velocimetry (PIV), high-resolution velocity fields were measured to quantify the mean and turbulent flow features (e.g., phase-averaged velocity fields, velocity gradients, spatial velocity distribution, turbulent kinetic energy, Reynolds stresses, vorticity, and shear stresses). Three different configurations of submerged bare castles and castles with scaled-down 3D-printed oyster surrogates were tested under low- and high-wave energy conditions. The results indicate that oyster castles significantly reduce shear stresses, and onshore near-bed turbulent kinetic energy when compared to unobstructed flows and bare castles. The effectiveness of oyster communities in controlling sediment mobility depends on the population density. Although oyster castle cases exhibited minimal suspended sediment with the tested conditions, the trapped sediment on different bare castle configurations demonstrated the impact of castle geometry on flow hydrodynamics and sediment transport. The data suggest that living oyster castles can effectively reduce near-bed stresses and turbulence levels. However, further quantification of sediment transport mechanisms and morphological changes is crucial in the design and implementation of these structures to ensure sustainable nature-based solutions for coastal protection.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Civil Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Alkhidhr, Salman Fahad M

Contributors dc:contributor

• Tinoco Lopez, Rafael Omar

• Oyster Castles
• Turbulence
• Nature-based Solutions
• Coastal Areas
• Suspension
• Morphodynamics

Statement dc:rights

• Copyright 2023 Salman Alkhidhr

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/120408

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F120408