Bas Hoonhout, Kees den Heijer


The dune assessment methods used to ensure the safety of the lower areas in The Netherlands are based on simple empirical relations that are, strictly speaking, only valid for infinitely long, uniform and straight coasts. The wide application of these relations is mainly justified due to intentional overestimation of the expected dune erosion. In context of climate change and expected sea level rise, it is worthwhile to investigate the needs for this overestimation before any physical measures are taken. This paper describes a research to the influence on the dune erosion process of two longshore phenomena that are neglected in these relations so far: coastal curvatures and oblique wave attack. It is shown that the normative retreat distance can increase over 100% for curvatures relevant for The Netherlands. Furthermore, it is shown that the sensitivity of dune erosion models changes when working with curved coastlines. It is also shown that the importance of several model parameters is influenced by coastal curvatures and special attention should be paid to the correlations between storm surge levels and wave parameters.


dune erosion; curved coastlines; reliability; assessment


Dillingh, D. and Visser, C. 1984. Rekenmodel voor extra duinafslag ten gevolge van een gradiënt in het langstransport als gevolg van een kromming van de kustlijn (Computational model for extra dune erosion due to a gradient in the longshore transport due to the curvature of the coastline), Centrum voor Onderzoek Waterkeringen (Centre for Research Water Defences), S-81.040 (in Dutch).

Fisherman, G. S. 1996. Monte Carlo: concepts, algorithms, and applications. Springer.


Hoonhout, B. M. 2009. Dune erosion along curved coastlines. Delft University of Technology, MSc Thesis.

JARKUS. 2008., Internet.

Meeuws, P. 1997. Het ontwerppunt bij Monte Carlo simulatie (Design point with Monte Carlo simulation). Delft University of Technology, MSc Thesis.

Roelvink, J. A., Reniers, A. J. H. M., van Dongeren, A. R., van Thiel de Vries, J. S. M., Lescinski, J. M., and McCall, R. T. 2006. XBeach model description and manual, UNESCO-IHE Institute for Water Education, N62558-06-C-2006.

Steetzel, H. J. 1990. Effect langstransport gradiëenten op mate van duinafslag, berkeningen met het DUROSTA-model (Effect of longshore transport gradients on the amount of dune erosion, computation with the DUROSTAmodel), WL | Delft Hydraulics, H298, part V (in Dutch).

Steetzel, H. J. 1992a. Vergelijking DUROS/DurosTa (Comparison DUROS/DurosTa), WL | Delft Hydraulics, H1201, part II (in Dutch).

Steetzel, H. J. 1992b. Verifcatie DurosTA (Verification DurosTA), WL | Delft Hydraulics, H1201, part I (in Dutch).

Steetzel, H. J. 1993. Cross-shore Transport during Storm Surges, Delft University of Technology, PhD Thesis.

Van Thiel de Vries, J. S. M. 2009. Dune erosion during storm surges, Delft University of Technology, PhD Thesis.

Vellinga, P. 1983. Duinafslag bij gebogen kusten, orde-grootte bepaling van de gradiënt van het langstransport tijdens duinafslag aan een gebogen kust (Dune erosion at curved beaches, determination of the order of magnitude of the longshore sediment transport gradient under dune erosion conditions), WL | Delft Hydraulics, M1263, part V (in Dutch).

Vellinga, P. 1986. Beach and Dune Erosion during Storm Surges, Delft University of Technology, PhD Thesis.

VTV2006. 2007. Voorschrift Toetsen op Veiligheid Primaire Waterkeringen (Regulation Safety Assessment Primary Water Defences), Ministerie van Verkeer en Waterstaat (Ministry of Transport, Public Works and Water Management), (in Dutch).

Walstra, D. J. R., Diermanse, F. L. M., van Geer, P. F. C., van Thiel de Vries, J. S. M., and van de Graaff, J. 2008. SBWDuinen2-Ontwikkeltraject, eerste aanzet tot de ontwikkeling van het 2011 Duintoetsinstrumentarium (SBWDuinen2-Developmentroute, first initiative to the development of the 2011 dune assessment instrument), Deltares, H5019.20 (in Dutch).

WL | Delft Hydraulics. 2006. Dune Erosion - Product 2: Largescale model tests and dune erosion prediction method, WL | Delft Hydraulics, H4357.

WL | Delft Hydraulics. 2007. Dune Erosion - Product 3: Probabilistic dune erosion prediction method, WL | Delft Hydraulics, H4357.

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