Paper No. 49
Presentation Time: 9:00 AM-6:00 PM

CHARACTERIZING SMALL ASSOCIATED ISLANDS OF PUERTO RICO AND USVI: PROVIDING A BASIS FOR FORECASTING SHORELINE RESPONSE TO SEA-LEVEL RISE


RUNYAN, Ryann M.1, PERISON-PARRISH, Elizabeth M.1, LOCURTO, Patricia L.1, SIEMER, Kyle W.2, JACKSON Jr., Chester W.3, BUSH, David M.1, LLERANDI-ROMÁN, Pablo A.4 and NEAL, William J.4, (1)Department of Geosciences, University of West Georgia, Carrollton, GA 30118, (2)Environmental sciences, University of Toledo, 2801 Bancroft Ave, Toledo, OH 49606, (3)Department of Geology and Geography, Georgia Southern University, Statesboro, GA 30460, (4)Department of Geology, Grand Valley State University, Allendale, MI 49401, rrunyan1@my.westga.edu

Puerto Rico is a densely populated island extremely vulnerable to coastal hazards. Coastal zone planning and management plays a vital role in reducing vulnerability. Coastal managers must rely on sound science on which to base planning decisions. This study centers on several techniques with which to describe island physical characteristics to help guide future land-use plans. Potential future sea-level rise (SLR) effects are the main focus of the study. Selected small associated islands of Puerto Rico and the United States Virgin Islands were chosen as study sites. Small size means slight changes in sea level can have large effects, and they can be evaluated relatively quickly and in great detail. Moreover, islands of varying geology, land cover, land use, and in different hydrographic regimes can be evaluated. Islands with an important recreational, historical, or cultural aspect were chosen.

In order to characterize each island, field and laboratory techniques were employed. Each island’s size, shape, position, and land use/cover were measured and/or delineated along several transects pathed on Google Earth imagery. Island topography was examined using USGS 7.5 Minute Series and Google Earth’s elevation profiles. Shoreline change was evaluated from air photos. In the field, beach profiles were obtained using the stake and horizon method, Real Time Kinematic GPS, and terrestrial LIDAR scans. At each field site, a geoindicator checklist evaluation was done as a basis for long-term monitoring.

The combination of a well-rounded physical description, quantifiable shoreline measurements, and long-term monitoring provides a comprehensive description of each islands’ physical conditions and allows for predictions of potential changes to each island under various sea-level rise scenarios. Ideally, the techniques developed here can be applied to the main islands of Puerto Rico and the USVI, as well as to the Caribbean basin in general.