On Borrowed Time: The Past, Present, and Future of Virginia's Barrier Islands under Differing Sea-Level Rise Scenarios

TL;DR

This study analyzes historical shoreline changes of Virginia's barrier islands and forecasts future impacts under sea-level rise scenarios, highlighting significant retreat and potential island loss by 2100.

Contribution

It provides a comprehensive analysis of past shoreline trends and projects future changes under different sea-level rise scenarios using advanced modeling techniques.

Findings

Shoreline retreat rates have increased over time.

Sea-level rise by 2100 may cause significant island erosion or disappearance.

Northern islands are more stable than southern ones.

Abstract

Virginia's barrier islands constitute one of the most undeveloped shorelines of the eastern US. Aside from a few islands in the north, the islands are uninhabited and managed for conservation. These islands play important environmental, cultural, and economic roles along Virginia's Eastern Shore. Climate change driven sea-level rise is already having a major impact on these islands and threatens their existence. We utilize transect analysis across each of the barrier islands to depict the shoreline change trends annually from 1850 to 2010. We then utilize time series forecasting and panel modeling to estimate future shorelines up to and including a best estimate 2099 CE shoreline. Results indicate that across almost all the islands, the shoreline retreat rate has been increasing over time. Additionally, we find that year 2100 CE sea-level rise scenarios are likely to accelerate the shoreline retreat occurring on these islands and may erase many of them all together. We find that the northern islands of Wallops and North Assateague will remain generally stable whereas many of the remaining islands will likely experience rapid shoreline retreat under future sea-level rise scenarios.