1. Multi-year evolution of a nourished beach preliminary results Kathelijne Wijnberg Stefan Aarninkhof

2. Objective Monitor a nourished beach with Argus video remote sensing technology in terms of one or more CSI’s defined in the Coastview project

3. Study area Egmond (NL), Argus site: Jan van Speijk lighthouse Beach nourishment: June 30 – July 5, 2000 location: y = 0 – 800 m volume 0.2x10 6 m 3

4. Data set Data set: 43 monthly intertidal bathymetries (IBMapper) t range : Jun. 1999 to Dec. 2002 y range: -680 m to +680 m z range: 0/-0.4 m NAP to + 0.9 m NAP  +0.2 m NAP contour (Mean Tide Level)

5. Monthly Intertidal Bathymetries (after: Caljouw / Nipius) Egmond station ‘Jan van Speyk’ June 1999 - August 2001

6. Approach to data analysis Temporal evolution of alongshore-averaged MTL position Temporal evolution of spatial patterns in MTL position set of spatial patterns empirically defined by EOF method (empirical eigenfunctions)

7. The data Mean :60 m60 m0 m St.dev. :29 m12 m 26 m Variance:844 m 2 149 m 2 (18%) 695 m 2 (82%)

8. Results EOF analysis Explained variance 184.3%(84.3%) 24.9% (89.2%) 33.3%(92.4%) 42.3%(94.7%) nourishment

9. Reconstructed MTL data

10. Conclusions At Egmond beach : Position of the shoreline (MTL) largely (82%) determined by positioning and amplitude of naturally occurring spatial patterns, rather than cross-shore movement of the beach as a whole Beach nourishment incorporated in dominant spatial pattern (explaining 84% of spatial pattern variance) within ~ 4 months

11. Future work Expand analysis to beach width and/or volumes Analyse morphological evolution in relation to hydrodynamic conditions (H, T, wave direction, water level), for prediction purposes.