A Framework for the Design of Coastal Dunes as a Nature-Based Solution

Abstract Coastal dunes offer ecosystem services like coastal protection, recreation, habitat and drinking water. To maintain, restore and create coastal dune areas, Nature-Based Solutions such as artificial blowouts, vegetation planting, sand fences and hybrid dunes are implemented. NBS project goals depend on the local issues that need to be addressed and the social and environmental setting. The primary project goal is often coastal protection. This objective depends on coastal erosion, while project goals that go beyond coastal protection rely on additional processes such as dune growth and vegetation development. A variety of models are available that simulate coastal erosion, dune growth and ecological processes. The suitability of these models to assess coastal dunes as NBS depends on the project objectives. We present a framework that can be used by researchers, engineers and planners to consider which numerical models are appropriate to quantitatively optimize NBS design. This framework is a first step towards increasing the use of numerical models in coastal dune NBS design. In the future, we aim to improve knowledge of unknown factors within the framework and improve the applicability of various models for assessing the objectives of coastal dune NBS projects.