Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Kirkland, Brenda L.

Committee Member

Skarke, Adam

Committee Member

Schmitz, Darrel W.

Committee Member

Sherman-Morris, Kathleen

Date of Degree

8-10-2018

Original embargo terms

Visible to MSU only for 3 years

Document Type

Dissertation - Open Access

Major

Earth and Atmospheric Sciences

Degree Name

Doctor of Philosophy

College

College of Arts and Sciences

Department

Department of Geosciences

Abstract

Nourishing beaches and coastlines is a common practice in mitigating the effects of coastal erosion. Cullet, a geologically compatible aggregate, has been suggested for use in beach nourishment practices instead of dredged sands. The goal of this research is to assess the suitability of using of cullet to replace dredged sand as a nourishment aggregate and to educate the public about the potential uses for cullet as it relates to coastal erosion. The compatibility of cullet to natural quartz sand relies heavily on the comparison of physical characteristics of the grains and ecological compatibility, which compares the microorganisms that naturally exist on a sand grain to the microorganisms that occur on cullet in the same environment. Results show under the same environmental parameters, similar assemblages and amounts of microorganisms grow on both natural quartz and cullet substrates. Initial resistance to the concept of purposely putting broken glass onto a beach from coastal communities and their visitors is anticipated. An opinion survey to measure potential acceptance of the practice and to test the value of a hands-on educational program was conducted using both online and in-person platforms. These surveys will guide the development of an education program regarding mitigation of coastal erosion and the potential impacts of beach replenishment with cullet. Results show there is a concern regarding cullet in beach environments, but a hands-on learning approach may aide in acceptance. A comparison of sediment transport models that analyze the movement of a nourished shoreline and associated variables was conducted. This comparison determined a need for a model specifically accounting for morphological grain characteristics, the grains break down over time, and influences on the life of a nourishment project. The variables of importance include grain size evolution throughout the lifespan of a nourishment project, grain angularity, and composition relative to the native sediments of a nourished beach. Ambiguity of grain variables need further refinement with a forthcoming model. The biota and survey results show favor of cullet as a suitable beach fill material, however models including hardness and composition might contest the results related to project lifespans and overall suitability.

URI

https://hdl.handle.net/11668/21213

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