In addition, there are some gaps in the data for technical reasons: from 16 August 1989 to 7 November 1991, from 15 December 1992 to 14 September 1994, and from 10 November 1994 to 4 October 1995. The shore at CRS Lubiatowo has a gently sloping beach from several to tens of metres wide. The dune toe lies from 1 to 2 m above the mean water level, whereas all points of the dune crest are at least 2 m higher than the dune toe

(adjacent to the landward edge of the beach). Locally, there is a small beach berm near the shoreline. Both the beach and dunes consist of fine quartz sand with a median grain diameter of around d50 ≈ 0.22 mm. Since there are practically no tides (a maximum of 6 cm), swell and wind waves are the only drivers of water motion in the nearshore PF-06463922 in vitro zone. The complex shape of the sea bed (see the example of a multi-bar cross-shore transect in Figure 2) causes multiple wave breaking and

the CTLA-4 antibody dissipation of much wave energy over the bars. According to investigations by Pruszak et al. (2008), only about 40% of the wave energy actually reaches the immediate proximity of the shoreline. The sea bed on the shore section of interest is characterized by bars, of which there may be from 3 to 5. The first stable bar is located at about 100–120 m, the second bar about 250 m and the third one 400–450 m from the shoreline; the fourth and fifth bars occur (sometimes as a single morphological entity) at a distance of 650–850 m offshore. In addition, there is often one more irregular sea bed form very close to the shoreline – a flat shoal that migrates in

various directions and disappears periodically. The shoreface has a mean slope of tan β = 0.015 (locally, at the shoreline, with a maximum of 0.04). The complicated nature of this coastal area, implying complex hydrodynamic and lithodynamic processes, is illustrated in Figure 3. Since 1983, geodesic surveys of the dunes and beach have been carried out every month along the 2.6 km section of shore. The tachymetry comprises cross-shore profiles every 100 m along the shore. This gives 27 measured transects. The results of the field investigations described above are plotted in Figure 4. The data comprising, by way of example, a short-term annual period from aminophylline September 2006 to September 2007 are shown in Figure 4a, whereas the data collected during the entire 25 year time span (1983–2007) are shown in Figure 4b. The shoreline position, interpreted as the distance of the shoreline point from a certain geodesic baseline, is denoted by ys, while the dune toe position, interpreted as the distance of the dune toe point from the geodesic baseline, is denoted by yd. Figure 4 shows that the range of shoreline migration ys is much larger than the range of changes of dune toe position.