Sea bottom forms influence the hydrodynamic processes along the Polish coast and facilitate the generation of semi-stable macro- and meso-circulation systems in the coastal zone. Due to hydrodynamic factors, in conditions of a permanent system of forms in the outer and inner nearshore zone, a specific coastal system of erosion/accretion forms has developed along the coastline. The macroforms of the Southern Baltic seafloor, occurring at the lower boundary of wave influence, help to conserve the trend prevailing along certain stretches, in certain regions, bistructures, groups of bistructures and in the whole coastal system of the Southern Baltic coast. The many year observations carried out along the Southern Baltic coast suggest that along many parts of the coast, erosion is permanent. One of the reasons for coastal zone changes is the geomorphological predisposition of the closer and further nearshore zone, inherited from the glacial and postglacial age. Investigations confirm that macro- and mesoscale forms on the seafloor play a basic role in the shaping of circulation systems. As a result of their long-, medium- and short-term influence, erosion / accretion bistructures of various scale are generated in the nearshore zone and on the shore. Changes in the thickness of the coastal zone’s dynamic layer, determined by means of parameterization of the nearshore zone and based on seismoacoustic profi ling, are also indicators of the erosion / accretion system of the coastal zone. Analysis of the obtained field data showed a distinct relationship between the systems of forms, the resources of the dynamic layer and the coastal abrasion / accretion systems in the region of the Southern Baltic coast.

Keywords: coastal barriers, sandbars, morpho-dynamic, South Baltic coast