The influence of beach buildings on coastal dune development is still largely unknown, and it could pose a risk to the functionalities coastal dunes provide. The objectives of this research are covered by the main research question: What is the influence of specific types of beach buildings on aeolian coastal dune development and what are suitable dune management measures? This study uses high resolution LiDAR elevation measurements taken with an UAV of two case areas in the Netherlands to investigate the influence of beach buildings on aeolian coastal dune development. Measurements are made of two stretches of beach located in Julianadorp and Sint Maartenszee, where various beach building types are present. Different dune regions are classified based on the presence of building types. The elevation data is discretized in grids that are placed adjacent to the dune foot along these classified regions. Elevation changes and cross-profile evolution of the dunes within these regions make it possible to consistently analyse differences in dune development with quantitative parameters.

Coastal dunes are dominant features along much of the world’s sandy coastlines serving as the first line of protection against coastal flooding. Besides this primary purpose, the coastal dunes also provide a variety of other functions such as the supply of drinking water, nature conservation and recreational areas. With the secondary functions in mind, the Dutch coastal management strategy changed in 1990 from erosion control and stabilization of the coastline (reactive) to a policy of dynamic preservation (pro-active) with the introduction of a law called ‘’Dynamic preservation of the Dutch coast’’. This new dynamic strategy naturally induced irregularities in dunes that were completely stabilized before. One of these irregularities is the formation of a blowout. A small depression or hollow in the foredunes formed by wind erosion or wave impact may grow in time as sediment from the beach and foredunes is transported into the back dunes. In several Dutch cases such a blowout feature was artificially initiated as the exchange of sediment from the coastal system into the back dunes enhances the biodiversity significantly. Due to the high importance of the coastal dune performance as flood protection, good understanding and prediction of the (dynamic) coastal dune system is desired. Lately, general interest in this topic increased even more due to new societal challenges, such as decisions on coastal development for longer time scales, more complex management settings and sustainability. Coastal dunes and blowouts are shaped by wind induced sediment transport (aeolian sediment transport), biological - and hydrodynamic processes. To better understand and increase the predictability of dynamic systems, this study focuses on simulating the development of artificially initiated blowout features by including the combination of these relevant processes in the numerical model AeoLiS. This process-based model was originally developed to simulate aeolian sediment transport in supply-limited conditions, such as coastal areas. The study describes simulations of several academic dune formations to validate the applicability of the different (new) processes that were included in the numerical model. Finally, all processes are combined in simulations of a practical case that is used to compare numerical model results to field data on the development of multiple artificially initiated blowout features in the Dutch coast at Meijendel.