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Article
Channel Shallowing as Mitigation of Coastal Flooding
Journal of Marine Science and Engineering
  • Philip M. Orton, Portland State University
  • Stefan A. Talke, Portland State University
  • David A. Jay, Portland State
  • Larry Yin, Stevens Institute of Technology
  • Alan F. Blumberg, Stevens Institute of Technology
  • Nickitas Georgas, Stevens Institute of Technology
  • Haihong Zhao, ARCADIS
  • Hugh J. Roberts, ARCADIS
  • Kytt MacManus, Columbia University
Document Type
Article
Publication Date
7-1-2015
Subjects
  • Storm surges,
  • Tides,
  • North Atlantic oscillation -- Environmental aspects,
  • North Atlantic Ocean -- Climate
Abstract
Here, we demonstrate that reductions in the depth of inlets or estuary channels can be used to reduce or prevent coastal flooding. A validated hydrodynamic model of Jamaica Bay, New York City (NYC), is used to test nature-based adaptation measures in ameliorating flooding for NYC’s two largest historical coastal flood events. In addition to control runs with modern bathymetry, three altered landscape scenarios are tested: (1) increasing the area of wetlands to their 1879 footprint and bathymetry, but leaving deep shipping channels unaltered; (2) shallowing all areas deeper than 2 m in the bay to be 2 m below Mean Low Water; (3) shallowing only the narrowest part of the inlet to the bay. These three scenarios are deliberately extreme and designed to evaluate the leverage each approach exerts on water levels. They result in peak water level reductions of 0.3%, 15%, and 6.8% for Hurricane Sandy, and 2.4%, 46% and 30% for the Category-3 hurricane of 1821, respectively (bay-wide averages). These results suggest that shallowing can provide greater flood protection than wetland restoration, and it is particularly effective at reducing "fast-pulse" storm surges that rise and fall quickly over several hours, like that of the 1821 storm. Nonetheless, the goal of flood mitigation must be weighed against economic, navigation, and ecological needs, and practical concerns such as the availability of sediment.
Description

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Originally published by the Journal of Marine Science and Engineering and can be found online: http://dx.doi.org/10.3390/jmse3030654

DOI
10.3390/jmse3030654
Persistent Identifier
http://archives.pdx.edu/ds/psu/16063
Citation Information
Orton, P.M.; Talke, S.A.; Jay, D.A.; Yin, L.; Blumberg, A.F.; Georgas, N.; Zhao, H.; Roberts, H.J.; MacManus, K. Channel Shallowing as Mitigation of Coastal Flooding. J. Mar. Sci. Eng. 2015, 3, 654-673.