Assessment of dune failure along the Dutch coast using a fully probabilistic approach

Abstract This paper describes an investigation into the added value of a fully probabilistic approach to dune resilience assessment over the currently applied deterministic and semi-probabilistic approaches. The method is applied to the Dutch coast but is generically applicable, provided of course the sufficient availability of data. The DUROS+ model in its most basic form was used to quantitatively assess dune resilience. The Monte Carlo method was used for the probabilistic investigation. Important research questions were (1) where can the DUROS+ model in combination with the fully probabilistic approach be applied along the Dutch coast? and (2) what is the alongshore variability of failure probability using this probabilistic approach? The main conclusion of the work presented in this paper is that the fully probabilistic approach provides valuable added insight with respect to the actual failure probability of transects. At the same time it is noted that the current dune erosion model in its most basic form is not able to cover all of the Dutch coast. Reasons lie in the availability of sufficient quality boundary conditions, applicability limits associated with model assumptions and insufficient quality coastal profile information. To extend the coverage of the analysis of failure probabilities along the Dutch coast it is recommended (1) to involve more process-based model concepts that can cope with the situations DUROS+ cannot, and (2) to expand currently available data on boundary conditions.