A METHOD TO SYSTEMATICALLY CLASSIFY DESIGN CHARACTERISTICS OF SAND NOURISHMENTS

Rik Gijsman, Jan Visscher, Torsten Schlurmann

Abstract


The decades of collected monitoring data of coastal profiles in combination with the decades of experience with sand nourishments in the Wadden Sea, forms an invaluable basis to study the inter-site efficiency of sand nourishment design. However, a systematic data-driven study of this type needs to be applicable for the inter-site varying (i) nourishment design strategies, (ii) coastal monitoring data sets and (iii) natural morphodynamics of the shorelines, respectively. This study introduces a four-step method able to systematically classify the influence of individual nourishment design parameters on the nourishment lifetime (i.e. the period of influence on the natural dynamics of a coastal profile). With the non-linear and adaptive principle component analysis (PCA) method, nourishment lifetimes of beach- and shoreface nourishments are extracted from data sets that describe different natural morphodynamics. Based on an application of the method to a limited number of nourishments placed in two coastal areas in the Netherlands (Ameland) and Germany (Sylt), increasing nourishment concentration, alongshore nourishment length and absolute nourishment peak elevation seem to increase the lifetime of beach- and shoreface nourishments. Nourishment lifetimes at profile more downstream seem to decrease for beach nourishments, but increase for shoreface nourishments. The method supports inclusion of additional coastal profiles and parameters related to the nourishment design, natural morphodynamics of the coastal profile and hydrodynamic forcing, to quantify nourishment design influences on nourishment lifetimes at different locations.

Full Text:

PDF

References


Aubrey, D. G. (1979). Seasonal patterns of onshore/offshore sediment movement. Journal of Geophysical Research: Oceans, 84(C10):6347–6354.

Dette, H. H. (1977). Effectiveness of beach deposit nourishment. Coastal Sediments Proceedings, pages 211–227.

Gijsman, R., Visscher, J., and Schlurmann, T. (in review). The lifetime of shoreface nourishments in fields with nearshore sandbar migration. Coastal Engineering.

Grunnet, N. M. and Ruessink, B. (2005). Morphodynamic response of nearshore bars to a shoreface nourishment. Coastal Engineering, 52(2):119–137.

Hamm, L., Capobianco, M., Dette, H., Lechuga, A., Spanhoff, R., and Stive, M. (2002). A summary of european experience with shore nourishment. Coastal engineering, 47(2):237–264.

Hanson, H., Brampton, A., Capobianco, M., Dette, H., Hamm, L., Laustrup, C., Lechuga, A., and Spanhoff, R. (2002). Beach nourishment projects, practices, and objectives - a european overview. Coastal engineering, 47(2):81–111.

Jolliffe, T. (2002). Principle component analysis. Springer.

Kroon, A., Larson, M., Möller, I., Yokoki, H., Rozynski, G., Cox, J., and Larroude, P. (2008). Statistical analysis of coastal morphological data sets over seasonal to decadal time scales. Coastal Engineering, 55(7-8):581–600.

Larson, M., Capobianco, M., Jansen, H., Rózy´nski, G., Southgate, H. N., Stive, M., Wijnberg, K. M., and Hulscher, S. (2003). Analysis and modeling of field data on coastal morphological evolution over yearly and decadal time scales. part 1: Background and linear techniques. Journal of Coastal Research, pages 760–775.

LKN.SH (2016). Fachplan küstenschutz sylt (in german).

Mulder, J. P. and Tonnon, P. K. (2011). Sand engine: Background and design of a mega-nourishment pilot in the netherlands. Coastal Engineering Proceedings, 1(32):35.

Ojeda, E., Ruessink, B., and Guillén, J. (2008). Morphodynamic response of a two-barred beach to a shoreface nourishment. Coastal Engineering, 55(12):1185–1196.

Rijkswaterstaat (2007). Richtlijnen onderwatersuppleties (in dutch).

Ruessink, B., Wijnberg, K., Holman, R., Kuriyama, Y., and Van Enckevort, I. (2003). Intersite comparison of interannual nearshore bar behavior. Journal of Geophysical Research: Oceans, 108(C8).

Spanhoff, R., Kroon, A., and De Keijzer, S. (2006). Shoreface nourishments as a natural laboratory with emphasis on the egmond case. Coastal Dynamics Proceedings.

Stive, M. J., de Schipper, M. A., Luijendijk, A. P., Aarninkhof, S. G., van Gelder-Maas, C., van Thiel de Vries, J. S., de Vries, S., Henriquez, M., Marx, S., and Ranasinghe, R. (2013). A new alternative to saving our beaches from sea-level rise: The sand engine. Journal of Coastal Research, 29(5):1001–1008.

Van Duin, M., Wiersma, N., Walstra, D., Van Rijn, L., and Stive, M. (2004). Nourishing the shoreface: observations and hindcasting of the egmond case, the netherlands. Coastal Engineering, 51(8-9):813– 837.

Wijnberg, K. M. and Terwindt, J. H. (1995). Extracting decadal morphological behaviour from highresolution, long-term bathymetric surveys along the holland coast using eigenfunction analysis. Marine Geology, 126(1-4):301–330.

Wilmink, R., Lodder, Q., and Sørensen, P. (2017). Assessment of the design and behaviour of nourishments in the north sea region. towards an nsr guideline for nourishments. Coastal Dynamics Proceedings.

Wright, L. and Short, A. D. (1984). Morphodynamic variability of surf zones and beaches: a synthesis. Marine geology, 56(1-4):93–118.




DOI: https://doi.org/10.9753/icce.v36.papers.95