BEACH-DUNE SYSTEM SUSCEPTIBILITY ASSESSMENT - APPLICATIONS AND VERIFICATION

The State of New Jersey contains areas of eroding bluff coastlines to the north and sand barrier-spit/island complexes to the south. Many of the sand beaches and shorelines along the New Jersey coast are sand starved and have been experiencing erosion for many decades. Much of this beach erosion is due to the effects of coastal storms such as hurricanes, and more commonly, northeast storms. These storms can cause catastrophic damage to the coastal infrastructure and adversely impact the livelihood of residents and tourists in these communities. Because it has a large coastal economy, New Jersey has been the most proactive state in the USA in undertaking shore protection projects to guard against beach erosion and maintain this valuable coastal resource.

The Richard Stockton College Coastal Research Center (CRC) has developed a state-wide GIS-based beach-dune system susceptibility assessment. The assessment incorporates multiple geospatial and remote sensing techniques (primarily the use of coastal LiDAR elevation data and aerial photography) into a knowledge-driven spatial data integration model. The goal of the assessment is to evaluate the performance of the oceanfront beach-dune system in response to various storm events. The storm event simulations used in the CRC beach-dune susceptibility assessment are consistent with FEMA storm classifications (i.e., 2-, 5-, 10-, 20-, 50-year storm events). In addition, the beach-dune susceptibility assessment provides federal, state, and local entities a useful tool to better manage a state's valuable coastal economy.

Recently, the New Jersey beach-dune assessment has been revised to simplify the spatial data preparation process through the use of a stand-alone GIS software application developed by PhotoScience, Inc. in cooperation with the CRC. The application, Beach-Dune Analyst (BDA), aids in the automation of many time-consuming tasks, which allows for rapid analyses of beach-dune systems on a regional scale. In addition, BDA allows for more thorough and timely field verification of the susceptibility model which aids in highlighting coastal areas vulnerable to storm damage (Figure 1). Field verifications of the susceptibility model were recently carried out in Harvey Cedars, New Jersey, following a northeast storm in November 2009, which resulted in a Presidential Disaster Declaration. The field observations coincide with the susceptibility model output (Figure 2).

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