Collaborative Proposal; Environment, Society, and Economy: Modeling New Behaviors Emerging from Coupling Physical Coastal Processes and Coastal Economies

Duke University, Durham NC

Investigators

Abstract

Human activities increasingly influence landscape change in many environments, both directly through construction and agricultural activities and indirectly through changes to the natural processes that shape landscapes. In turn, the processes that shape landscapes affect humans, often posing natural hazards. In coastal environments these two-way interactions involve coastal erosion, which threatens coastal communities, and shoreline-stabilization efforts, which affect the evolution of the surrounding coastline. Previous numerical modeling has shown that localized shoreline stabilization efforts, such as nourishing beaches by adding sand, can alter shoreline erosion rates even in distant parts of a coastline. Thus, a coastal community that chooses to stabilize its shoreline inadvertently affects other communities, so that the economies and management of coastal communities are linked. This research will use numerical modeling to address the kinds of coupled environmental and economic patterns that emerge under different decision-making regimes. An economic component to the numerical modeling, based on an empirical relationship between property values and beach width, determines the beach replenishment strategy that optimizes the net benefits to an individual community. Coupling this model to a coastline-change model reveals the unexpected ways that communities unwittingly interact with one another, and the feedbacks that induce some communities to shoulder more of the shoreline stabilization effort than others. In contrast, a different economic-model approach will analyze what pattern of beach replenishment would maximize the net benefits of a stretch of coastline more holistically. This project will investigate the different patterns of coastline change and economic benefits these approaches would produce under different scenarios for: 1) sea-level rise; 2) changing storm climate; 3) coastline physical and economic attributes; and 4) diminishing common-pool sand resources and the associated increase in the price of beach replenishment. Changes in coastal environments can no longer be understood by considering either physical or economic processes in isolation; this research provides a necessary step toward understanding the dynamics of developed coastlines?what causes the patterns of shoreline erosion and economic impacts under various possible futures (given uncertainties in climate change and economic driving factors including sand resources). The results of computer-model experiments testing how coordinated planning for shoreline stabilization could increase net wealth will not only increase basic knowledge about how coupled human/landscape systems work, but it could lead to improvements in coastal management strategies.