Modeling the Biogenic Effects of Freshwater Mollusks on Bedload Transport and Dynamics in a Gravel-Bedded Stream

Application of physical modeling in relation to the influence of ecosystem engineers such as the freshwater mussel has been a common source of interest in ecohydrogeomorphic literature, limited by methods and complexity of application. This thesis investigates the influence of biogenic variables on sediment characteristics, the interaction of biogenic alterations in sediment transport modeling, and the range of spatial scales used to identify biogenic effects. Methods used to investigate potential influences include multivariate regression analysis performed for organism (freshwater mussel and Corbicula Fluminea) density, mussel tribe distribution, and biomass; two 1D HEC-RAS sediment transport models integrated with biogenic Manning's roughness and organism-sediment particle size distributions for bankfull discharge events; and reach and patch-scale spatial analysis examining relationships between biogenic variables and sediment particle quantile D50. This study found that separated freshwater mussel and Corbicula Fluminea densities proved to be the most influential multivariate scenario, and reach-scale observation investigating the differences between sites proved to be a better indicator of biogenic sediment relationships than within site-scale analysis. Changes in organism-altered roughness demonstrated site-dependent responses that either disrupted or protected bed sediments. In conclusion, biogenic variables are worth integrating into existing physical models and generally have a protective influence on bed sediments when applied in sediment transport modeling.

Grantor dc:publisher

University of Alabama Libraries

Year dc:date.issued

2024

Author dc:creator

• Tatum, Taylor A.

Advisor dc:contributor.advisor

• Davis, Lisa

Contributors dc:contributor

• Atkinson, Carla
• Cohen, Sagy

• Ecohydrogeomorphology
• Fluvial geomorphology
• Sediment modeling
• Sediment transport

Statement dc:rights

• All rights reserved by the author unless otherwise indicated.

Language dc:language.iso

en_US, English

Dc Identifier Other

1113894

OAI identifier oai:identifier

oai:ir.ua.edu:123456789/15373