COASTAL VULNERABILITY AND RESISTANCE: A YEARLONG STUDY OF STATEN ISLAND BEACHES

On October 29th, 2012, superstorm Sandy made landfall on the mid-Atlantic coast causing severe damage throughout the region. The eastern coastline of Staten Island in particular showed its vulnerability to storm surges as the neighborhoods around the surrounding area were extremely inundated, resulting in lives lost and billions of dollars in damages. Surveying on the beach during previous studies has shown that the beach in question is reflective, suggesting limited seasonal changes but can experience significant erosion during major storm events. This current work expands on the initial surveying completed in 2018 by taking regular beach surveys over the course of a year. These surveys consist of measuring the slope of the beach in 2-meter intervals, using a ranging pole and a transit, as well as collecting sediment samples at the low tide ridge, the high tide mark, as well as other significant locations throughout the beach.

In this project, beach surveys were conducted between summer of 2022 to 2023 using comparable methodologies. Building upon previous studies, these measurements were also brought into ArcGIS to better understand the coastal morphology. Inverse distance weighted (IDW) interpolation was used to identify values between sampling transects to create a continuous dataset of the beach surface. This technique will help us understand how the coastline has responded to disturbances to better predict the future response of the coastline to storm events.

Results confirm that the beach is reflective, based on the beach face slope (5° to 9°), ridge of coarse sediment at the low tide line and lack of significant variation in morphology over the course of the year. Most of the variability is related to longshore currents interacting with groins, resulting in areas of erosion and deposition with movement of between 1-2 meters. Winter storms also move some beach face and berm sediment offshore, and it gradually builds back over the summer. Overall, this survey provides a useful baseline that can be used to understand changes that will occur after the construction of a buried seawall and the influence of future storms.