Researchers in North Carolina have developed a simulation model to explore how coastal management activities meant to protect barrier islands from sea-level rise can impact the natural processes that sustain these islands. The researchers, including A. Brad Murray from Duke University and Laura Moore from the University of North Carolina at Chapel Hill, have published a pair of studies on this work in Earth Futures. Barrier islands are important coastal landforms that absorb wave energy, lessen storm surge, and provide protection to mainland coastlines. However, coastal communities on these islands are facing increasing risks due to sea-level rise caused by climate change.
Coastal communities have been relying on strategies like beach nourishment and engineered solutions to adapt to the changing climate threats. However, some of these interventions can disrupt the natural processes that have been key to maintaining the barrier islands above water level. For example, the practice of protecting roads with tall dunes and removing overwashed sand from paved surfaces can hinder the natural replenishment of sand on the islands. The researchers’ model shows that the success in preventing storm impacts can lead to decreased resilience in the barrier system in the long term, raising difficult tradeoffs when managing coastal areas to preserve coastal living.
The researchers’ simulation model indicates that the longevity of a barrier island’s habitability depends on the coastal management strategies and the climate scenarios implemented. For instance, shifting away from traditional practices like building tall dunes to protect roads or bulldozing overwashed sand off paved surfaces can help barriers adapt better to sea-level rise. Strategies that allow for natural evolution of shoreline segments, such as building bridges instead of roadways, can enhance the resilience of the barrier system in those areas. However, it is important to note that management decisions in one area can impact erosion rates in adjacent areas, affecting neighboring communities.
The study emphasizes the need for stakeholders in neighboring coastal areas to collaborate and consider the interconnectedness of coastal management decisions. Recognizing that there is no perfect solution, the researchers stress the importance of understanding the entire barrier system and its response to various management choices to assess the sustainability of coastal development in the long term. The model developed by the researchers helps in evaluating multiple factors involved in managing coastal areas to ensure that decisions are not inadvertently exacerbating issues over time, and to assess the tradeoffs associated with different strategies.
The funding for this study came from the National Science Foundation, University of Virginia, and the Gulf Research Program Early-Career Research Fellowship. The findings of this research highlight the complexities involved in coastal management, especially in the face of increasing sea-level rise and climate change impacts. By considering the natural processes that sustain barrier islands and the potential disruptions caused by human interventions, stakeholders can make more informed decisions regarding coastal development to ensure the long-term resilience of these vital coastal ecosystems.
