The dune coast − the state just prior to the construction of hard engineering protection structures (Ustka-Jarosławiec, the Southern Baltic)

The state of a fragment of the southern Baltic Sea shore was assessed on the basis of historical maps, aerial images, the digital elevation model and the data on the geological structure of the nearshore bottom. The alternate erosion and accumulation sections of the coast were observed. They are moving toward the east related to the migration of mega beach cusps. The infrastructure of the military training ground located in the western part of the study area is threatened with abrasion. In 1889-2012, the nearby seashore retreated by an average of 257±11.5 m. The recorded average rate of changes for the period of 1989-2012 was -2.6±0.22 m year^-1. In the eastern part of the study area, at the bottom of the nearshore, a thick layer of sand determines the development of new accumulation sections of the coast. The state of the seashore, recognized in this paper, will change due to the construction of four concrete sea-walls. Their operation will disrupt the natural processes described in these studies.