MODELING AND MAPPING 21ST CENTURY BEACH SAND SUPPLY AND DEMAND ALONG THE DELAWARE-MARYLAND ATLANTIC COASTLINE AND BEYOND (Invited Presentation)

Rising sea levels and increasingly frequent major storm surges related to climate change will continue to threaten coastal habitats and communities along the Mid-Atlantic coastline throughout the 21^st century and beyond. For decades, beach nourishment has been the primary coastal stabilization strategy for protecting both natural and man-made assets in this region. In an ongoing effort with the U.S. Bureau of Ocean Energy Management, the Delaware Geological Survey is developing methods for forecasting sand resource demand and modeling potential sand resource supply along the Mid-Atlantic coastline. This work will provide valuable information for offshore resource managers that must plan for competing offshore interests such as wind energy infrastructure, shipping, carbon sequestration projects, and more.

We estimated that between 50 and 150 million cubic yards of offshore sand may be required by 2100 to meet the demands of just the Delaware and Maryland Atlantic coastline and suggest that additional sand resource areas may be needed by the middle of the century. Forecast uncertainty reflects differences in major storm surge frequencies and sea level under different climate change scenarios. We identified numerous promising sand resource units using a machine learning approach that utilized offshore core logs and bathymetric derivatives. However, we highlight the wide array of competing interests on the continental shelf that complicate or restrict access to these resources. Data products from this project include forecasts of sand resource demand under different climate scenarios and maps of modeled sand resource units with estimated sand volumes. The results of this project will help guide offshore geological studies and coastal resiliency planning in the 21st century.