A linear relationship between wave power and erosion determines salt-marsh resilience to violent storms and hurricanes

Proceedings of the National Academy of Sciences of the United States of America
By: , and 

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Abstract

Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title A linear relationship between wave power and erosion determines salt-marsh resilience to violent storms and hurricanes
Series title Proceedings of the National Academy of Sciences of the United States of America
DOI 10.1073/pnas.1510095112
Volume 113
Issue 1
Year Published 2016
Language English
Publisher National Academy of Sciences
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 5 p.
First page 64
Last page 68