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The Ostend beach (adjacent to Mariakerke), located almost in the middle of the Belgian coast, is a dissipative beach, characterised by a low beach gradient, a surf zone with the presence of numerous spilling lines of breakers and by fine to medium sandy sediments (D50=0.214 mm). The study area is densely populated with apartment buildings on the dyke and a promenade protected by a seawall without naturally-developed dunes. The coastal defence is designed for to give protection for a T100 storm event (return period of 100 years).
The Belgian coast has a bi-diurnal tide with a small asymmetry and an average tidal range of 4m. The tidal wave moves along the coast from west to east. The tidal range decreases in the same direction by +/- 0.5 m. Spring tides occur twice a month when the tidal variation has reached its maximum (+/- 5 m), while for neap tides occur the tidal range reaches its minimum, i.e. +/- 3 m. The tidal curve has an asymmetric shape because the low tide lasts half an hour longer than the high tide. Meteorological circumstances can significantly influence the curve as well. Long-lasting intense winds may influence the water level, resulting in extremely low or high water levels. This important tidal range is linked to quite significant tidal currents, which exceeds generally 1.5 knots in the near shore areas. Because of the shallow seas and the short fetch, waves are typically short crested at the Belgian coast.
The wave climate along the coast is mainly determined by meteorological circumstances, predominantly westerly winds, and by the shallow depth of the North Sea. Under normal circumstances the wave along the coast is lower than 1 meter. During (heavy) storms wave heights of over 5 meters can occur. The wave period is 3 to 4 seconds under calm weather conditions, but during storms it can reach 10 to 15 seconds \citep{IMDC2005}.
Between 08/11/2007 0000Z and 1800Z an active depression moves from just southeast of Iceland towards Norway and settles afterwards in south Scandinavia. On the back of this depression, strong northerly wind fields develop and spread over the Norwegian Sea and the North Sea. This situation causes high water levels and waves along the North Sea Coasts \citep{Versluys2007}.
Currently, beach and dune erosion at the Belgian coast is estimated with Durosta. For the storm of November 2007, calculations have been performed with Durosta for Ostend beach and compared with the measurements. Durosta has been run with default settings. Several profiles (1D) have been modelled on a grid that varies from 6m offshore to 1m near the seawall. The seawall has been included as a non-erodible element.
To compare the performance of XBeach with Durosta, the same 1D-profiles haven been modelled for Ostend beach. The grid in XBeach has been chosen identical to that of Durosta and varies from 6m offshore to 1m near the seawall. The performance of XBeach will be compared with Durosta. Since Durosta is a 1D model, also XBeach has been applied in 1D mode.

In \autoref{fig:MICORE_Mariakerke_and_Ostend_Beach_s116a_profiles} the model results from XBeach and Durosta are compared with the measurements for the November 2007 storm at Ostend beach. Additionally the Brier Skill Score has been determined between the dyke and -500m.

% if interpret:

Both XBeach and Durosta give a more uniform beach profile than is observed in the measurements. Small bars in the profile are hardly predicted with both models. For the presented results XBeach obtains a better score than Durosta. 
Comparing both models it is concluded that XBeach delivers (also for most other cases presented in the WP4 report) a slightly better result than Durosta. Especially the prediction of the beach erosion front seems a bit more accurate in XBeach.

% endif

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##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/s114a/', 'profiles.eps')}
##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/s115a/', 'profiles.eps')}
${tools.image('MICORE_Mariakerke_and_Ostend_Beach/s116a/', 'profiles.eps')}
##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/s117a/', 'profiles.eps')}

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##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/2d/', 'profile_113.eps')}
##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/2d/', 'profile_114.eps')}
##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/2d/', 'profile_115.eps')}
##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/2d/', 'profile_116.eps')}
##${tools.image('MICORE_Mariakerke_and_Ostend_Beach/2d/', 'profile_117.eps')}