<%namespace name="tools" file="tools.tex"/>

The Polish study site is the 14 km long Dziwnow Spit of barrier type built of Holocene deposits (mainly sands) with dunes 3.5 to 10 meters high. Behind the spit there are relatively wide lowlands of glacial or glaciofluvial origin, in most cases filled with peat. Their surface is 1 to 3 m above sea level. In the lowlands alos the Kaminski Lagoon is found with a rather small depth (maximum 2-3 m). At the middle of the spit there is a connection between the lagoon and sea (Dziwna). The mean beach width calculated for the pilot area is 33 m.
The average tide range in the Baltic is very small and is less then 10 cm. This is due to the small area of the Baltic, its geographical situation and the presence of the Danish Straits, which prevent propagation of North Sea tides into the Baltic. Thus, surface waves (wind waves and swell) are the most important factor of the Baltic coastal zone hydrodynamics. The wave climate in Poland is highly diversified because of the wealth of fetches and wind speeds occurring throughout the year.
Since 1 June 2008, (from the beginning of observations taken within MICORE project) 1 extreme storm (12.10.2009) was noticed which caused significant morphological changes at the shore. The storm return period was about 4 years and was simulated with the XBeach model. 
The storm occurred on 12.10.2009 and lasted for almost 4 days (93hours). The highest sea level observed on tide gauge located in the Dziwna (Dziwnow Port Authority area) was 0,76 m. above mean sea level. The maximum significant wave height (Hs) reached 3.2 m and teh maximum peak period (Tp) was 11.17 sec.

The XBeach model was run for profile 386 in 1D mode. The profile was interpolated to a cross-shore varying grid with a minimum cell size of 3 m. Offshore wave data timeseries from the WAM model were inputted to XBeach using a Jonswap spectrum and setting instat=41. Wave direction values were changed to 270 degrees, which means that incoming waves are shore normal. Surge input data were taken as the hourly mean sea level.

% if interpret:

It is visible from the simulation (see \autoref{fig:MICORE_Dziwnow_Spit_386_profiles}), that at this stage the amount of dune erosion is overestimated by XBeach according to post-storm data.

% endif

${tools.image('MICORE_Dziwnow_Spit/386/', 'profiles.png')}
##${tools.image('MICORE_Dziwnow_Spit/386_5/', 'profiles.png')}
##${tools.image('MICORE_Dziwnow_Spit/391/', 'profiles.png')}

##${tools.image('MICORE_Dziwnow_Spit/2d/', 'overview.png')}
##${tools.image('MICORE_Dziwnow_Spit/2d/', 'profile_pr04.png')}
##${tools.image('MICORE_Dziwnow_Spit/2d/', 'profile_pr18.png')}
##${tools.image('MICORE_Dziwnow_Spit/2d/', 'profile_pr20.png')}