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Coastal Adaptation Impacts on Water Quality and Flooding

Principal Investigators Philip Orton, Nickitas Georgas, Alan Blumberg, Stevens Institute of Technology; James Fitzpatrick, HDR, Inc.

Funding Agency:  Department of Interior, National Parks Service

Project Period:  November 2014 – October 2016

  1. Summary

Hundreds of thousands of NYC residents in Jamaica Bay’s watershed live on land vulnerable to flooding from a hurricane storm tide. Many types of coastal protective features, ranging from surge barriers to natural features like wetlands and oyster beds, have been suggested as solutions for coastal flooding around the bay. Water quality and storm damage avoidance are integrally linked research topics, as storm protection efforts can harm water quality and alter ecosystems. A project is outlined here to improve upon existing mathematical computer modeling capabilities for Jamaica Bay and to run experiments to study climate change, sea level rise and coastal adaptation impacts on water quality and storm damages. An important part of the project plan is to build Jamaica Bay Science and Resilience Institute consortium technical capacity by making these models available for consortium member use.

View of New York City's skyline, over Jamaica Bay wetlands (credit: Jeanne Hillary)

View of New York City’s skyline, over Jamaica Bay wetlands 

  1. Introduction

Hurricane Sandy was a painful reminder that coastal storms are among the world’s most costly and deadly disasters, capable of causing tens-to-hundreds of billions of dollars in damages and destroying entire neighborhoods. For New York City, hundreds of thousands of NYC residents live at low elevations (below 5 m) surrounding Jamaica Bay, a bay situated on the south-east edge of the city.

Jamaica Bay has an area of 107 km2, is ecologically rich, and has some of the largest remaining tidal wetlands in New York State. However, aerial photographs from 1974 to 1999 show that 2.5 km2 of marshes in the bay’s interior and nearly 80 percent of the interior islands vegetative cover disappeared over this period [Hartig et al., 2002]. The total loss of interior wetlands for the bay since the mid-1800s is estimated to be 12000 of the original 16000 acres [DEP, 2007], and the bay once supported a large oyster fishery producing 700,000 bushels of oysters per year in the early 1900s [Franz, 1982].

Many types of coastal protective features, ranging from surge barriers to natural features like wetlands and oyster beds, are being studied as solutions for coastal flooding. Decisions on which coastal protections to use require detailed studies using computer models that are not available or fully developed for most locations. These models must include many features in addition to physical storm surges, such as chemistry and water quality, to be able to evaluate whether water quality and ecosystems will be harmed by the protections.

Mathematical modeling is useful for understanding water circulation, waves, flooding, water quality, and ecosystem dynamics, among other topics.  Model experiments can reveal dynamics of each of these systems, within the constraints of a given model construct.  Modeling connects with observations, which are used for model development and validation, yet are also interpolated in time and space by the model, to provide a more complete picture a water body, such as Jamaica Bay.  As a result, modeling has major benefits for any comprehensive analysis of the bay, such as for quantification of flood damage reductions.  Modeling also connects with decision analysis, as it opens the door to experimentation to understand future changes due to climate change, sea level rise, and human alterations around and within the bay.

A project is outlined here to improve upon existing modeling capabilities for water quality, flooding and waves for Jamaica Bay, and to run experiments to study climate change, sea level rise and coastal adaptation impacts on water quality and storm damages. An important part of the plan is to build Jamaica Bay Science and Resilience Institute consortium technical capacity by making these models available for consortium member use at CUNY’s High Performance Computing Center (HPCC).

 The primary goals in the project will be to:

  • Improve the existing water quality modeling in Jamaica Bay (J-Bay) with enhanced model representations of wetlands, macro-algae, and wetland and benthic chemical/nutrient fluxes.
  • Improve hydrodynamic model representations of J-Bay wetlands and air-sea interaction
  • Utilize higher-resolution modeling in the bay and improve modeling of exchanges with the coastal ocean by coupling the J-Bay models with inputs from regional scale models
  • Calibrate the improved models using data collected by the consortium and USGS in J-Bay
  • Run experiments to study climate change, sea level rise and coastal adaptation impacts on flooding, waves, water quality and residence time

The two-year project brings together some of the best ocean and water quality modelers from the region, leveraging extensive experience with Jamaica Bay.  It will also include an educational research component and be carried out, in part, by a PhD student and a post-doctoral researcher.

References

DEP (2007), Jamaica Bay Watershed Protection Plan, Volume 1, New York, 128pp pp.

Franz, D. R. (1982), An historical perspective on mollusks in Lower New York Harbor, with emphasis on oysters, Ecological Stress and the New York Bight: Science and Management. Columbia SC: Estuarine Research Federation, 181-197.

Hartig, E. K., V. Gornitz, A. Kolker, F. Mushacke, and D. Fallon (2002), Anthropogenic and climate-change impacts on salt marshes of Jamaica Bay, New York City, Wetlands, 22(1), 71-89.

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