Simulating dune evolution on managed coastlines: Exploring management options with the Coastal Recovery from Storms Tool (CReST)

Abstract

Despite the importance of coastal dunes to many low-lying coastal communities and ecosystems, our understanding of how both climatic and anthropogenic pressures affect foredune evolution on time scales of years to decades is relatively poor. However, recently developed coupled numerical modeling tools have allowed for the exploration of the erosion and growth of coastal foredunes on time scales of hours to years. For example, Windsurf is a new process-based numerical modeling system (Cohn et al. 2019a) that simulates the evolution of dune-backed sandy coastal systems in response to wave, wind, and water level forcings. CReST, developed as a front-end interface to Windsurf, aims to add the ability to incorporate beach nourishment and dune construction, beach and dune grading, dune grass planting scenarios, dune grass removal, and the presence of hard engineering structures into the model framework to better account for the complex dynamics of managed coastlines. Initial model sensitivity tests suggest that the model provides a flexible framework to investigate the complex interactions between beaches and dunes for a variety of exploratory and applied applications.