Wave transformation at a saltmarsh edge and resulting marsh edge erosion: observations and modeling

This study examines wind generated waves during winter storms, their transformation/attenuation near the marsh edge, and the resulting saltmarsh edge erosion. A simple numerical model for wave generation, transmission and marsh edge erosion was developed and validated against observations from Lake...

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Bibliographic Details
Main Author: Trosclair, Kevin J
Format: Others
Published: ScholarWorks@UNO 2013
Subjects:
Online Access:http://scholarworks.uno.edu/td/1777
http://scholarworks.uno.edu/cgi/viewcontent.cgi?article=2801&context=td
Description
Summary:This study examines wind generated waves during winter storms, their transformation/attenuation near the marsh edge, and the resulting saltmarsh edge erosion. A simple numerical model for wave generation, transmission and marsh edge erosion was developed and validated against observations from Lake Borgne, Louisiana. Results suggest that meteorological conditions modify the local water depth via wind or wave setup and atmospheric pressure, thus exerting a first order control on the location of wave attack, which in turn determines the type of wave forces (shear vs. impact) that dominate the erosion process. Scarp failure follows, at a location determined by water level, creating multiple erosive scarps and terraces. High measured erosion, likely due to marsh edge destabilization followed by subsequent frontal passage forces differential marsh erosion, exposing underlying substrate to further erosion. A conceptual model for marsh edge retreat is developed using these observations and supported further by model predictions.