History as a guide to the future for cities: coastal storms and Jamaica Bay in New York City as an example.

Abstract:

History can provide a guide to the future by revealing the physical climatic and geomorphological dynamics with which cities must contend. We used historical maps from the U.S. Coast Survey and the Stevens Estuarine and Coastal Ocean Model (sECOM) to simulate how and where coastal flooding from storm surge affected the Jamaica Bay region of southeastern New York City at different points in time. This area, which houses approximately 1.2 million people today and the John F. Kennedy International Airport, was heavily impacted by coastal flooding during Hurricane Sandy. Historical analysis showed that the Rockaway Peninsula was an active barrier island system up until the early twentieth century, growing approximately 70 meters per year to the west between 1844 - 1891. Older historical maps made by American and European cartographers from 1524 - 1844 suggest that Jamaica Bay may have been a much more open system, with few or no interior marsh islands, at the time of European discovery. From these studies, we constructed digital terrain models and land cover maps for two historical periods: ca. 1870s and ca. 1609, and today. Storm simulations of hurricanes over the historical and present-day landscapes showed how a smaller inlet, shallower channel depths, and larger floodplains all can reduce the height of flooding inside the bay, and suggested a series of leverage experiments that test the efficacy of present-day green infrastructure interventions to lessen peak flood heights while maintaining tidal flushing. By combining history, modelling, and policy-relevant scenarios, we believe we have developed a reshreshing and accessible toolkit for policymakers thinking about resilience measures in coastal cities like New York.