Geomorphic Versus Climatic Drivers of Changing Coastal Flood Risk

PI Philip Orton, Stevens Institute of Technology

Co-PI Thomas Wahl, University of Central Florida 

Co-PI James Booth, City University of New York

Co-PI Stefan Talke, Portland State University / California Polytechnic State University

Funding agency/program:  National Science Foundation, Prediction of and Resilience to Extreme Events (PREEVENTS)

Project Period:  June 2019 to May 2023

Abstract

Coastal flooding is one of the most dangerous and damaging natural hazards that societies face, and coastal development and climate change are causing a dramatic rise in vulnerability.  Since the 19^th century, estuary channels have typically been deepened and widened by a factor of two or three, harbor entrances have been deepened and streamlined, and a large proportion of wetlands have been filled over and replaced with neighborhoods.  Such geomorphic changes increase flood risk by reducing natural resistance to storm surge and tides.  Similarly, sea level rise and climate-modulated variations in storm characteristics such as intensity, size and track path also alter flood risk.  The overarching goal of the proposed research project is to reveal and contrast the mechanisms by which these geomorphic and climatic changes alter flood risk.  This goal will be met using a combination of computational modeling, historical climate and storm surge data analysis, and theory-based synthesis.  The study will provide support for a postdoctoral research associate and several graduate students and undergraduates, including underrepresented groups.  It will improve the well-being of communities within urbanized harbors and estuaries by highlighting coastal development practices that can worsen coastal flooding.  The project plan increases scientific literacy and engagement, and connects the research to applications through interactions with local stakeholders and governments, as well as the US Geological Survey and the US Army Corps of Engineers.

The project will improve the understanding and separation of climatic and geomorphic factors in coastal flooding through several elements of novel research and technical innovation.  The investigators will use a unique tide-gauge data set that extends back to the 19^th century together with contemporary, retrospective, and idealized hydrodynamic models to elucidate system sensitivities.  Well-known, simplified insights into tidal dynamics will be tested for storm surge, then used to help interpret how altered local topography, bathymetry and wetland area have changed frictional damping and long-wave mechanics.  A combined analysis of climate, storm characteristics, and morphologic change will identify the modes and pathways through which climate variability and bathymetric change modulate storms surges.  Advanced non-stationary univariate and multivariate statistical models will be developed and employed to incorporate these changes and assess how statistical properties relevant for coastal design and risk assessments respond.  A flood model inter-comparison workshop will help quantify relevant modeling sensitivities, which will help to improve estuary and floodplain predictions for the academic and operational forecasting community.

SELECTED PROJECT PUBLICATIONS

Li, S., T. Wahl, S. A. Talke, D. A. Jay, P. M. Orton, X. Liang, G. Wang, and L. Liu (2021), Evolving tides aggravate nuisance flooding along the U.S. coastline, Science Advances, 7(10), eabe2412, doi:10.1126/sciadv.abe2412.  Open access.

Orton, P. M., E. W. Sanderson, S. A. Talke, M. Giampieri, and K. MacManus (2020), Storm tide amplification and habitat changes due to urbanization of a lagoonal estuary, Natural Hazards and Earth System Science, 20(9), 2415-2432, doi:10.5194/nhess-20-2415-2020. open access.

Pareja-Roman, L. F., Orton, P. M., & Talke, S. A. (2023). Effect of estuary urbanization on tidal dynamics and high tide flooding in a coastal lagoon. Journal of Geophysical Research: Oceans, 128, e2022JC018777.  web

De Leo, F., Talke, S.A., Orton, P.M., Wahl, T., 2022. The effect of harbor developments on future high‐tide flooding in Miami, Florida, Journal of Geophysical Research, doi:10.1029/2022JC018496.  web

Rodríguez Enríquez, A., Wahl, T., Baranes, H., Talke, S. A., Orton, P. M., Booth, J. F., & Haigh, I. D., 2022. Predictable changes in extreme sea levels and coastal flood risk due to nodal and perigean astronomical tidal cycles. Journal of Geophysical Research, 127.  web

Strauss, B., P. Orton, K. Bittermann, M. K. Buchanan, R. E. Kopp, S. Kulp, C. Massey, H. de Moel, and S. Vinogradov, 2021. Economic Damages from Hurricane Sandy Attributable to Sea Level Rise Caused by Anthropogenic Climate Change, Nature Communications, 12(2720), doi:10.1038/s41467-021-22838-1.  open access

Talke, S.A., Familkhalili, R. and Jay, D.A., 2021. The influence of channel deepening on tides, river discharge effects, and storm surge. Journal of Geophysical Research: Oceans, 126(5), p.e2020JC016328.

Familkhalili, R., Talke, S.A. and Jay, D.A., 2020. Tide‐storm surge interactions in highly altered estuaries: How channel deepening increases surge vulnerability. Journal of Geophysical Research: Oceans, 125(4), p.e2019JC015286.

Familkhalili, R., Talke, S.A. and Jay, D.A., 2022. Compound flooding in convergent estuaries: insights from an analytical model. Ocean Science, 18(4), pp.1203-1220.

Towey, K.L., Booth, J.F., Rodriguez Enriquez, A. and Wahl, T., 2022. Tropical cyclone storm surge probabilities for the east coast of the United States: a cyclone-based perspective. Natural Hazards and Earth System Sciences, 22(4), pp.1287-1300.