ИСТИНА

The most dynamic landforms of the studied coast are sandy beaches. Those are formed at the base of cliffs partly covering shore platforms developed in low-resistance bedrock. Only glacial boulder loams are characterized by relatively higher resistance to wave action. Sediment supply from rivers or from sea bottom erosion is minimal. A significant portion of sediment delivered onto the beaches from the underwater offshore slope during moderate waves periods is represented by sand previously washed away from the beaches and cliffs during heavier storms but still remaining above the coastal zone lower limit. Main source of sediment for beaches are wave erosion and denudation of cliffs. Abrasion occurs only during heavy storms with typical return period exceeding one year. During periods of low to moderate wave intensity it in most cases affects colluvial fringes and landslide bodies accumulated along the cliffs toes rather than cliff faces themselves. Other processes acting on cliffs, mainly landslides, falls and screes are main contributors into the coastal zone sediment budget. Runoff erosion processes on cliffs are not intensive. Colluvial material deposited along the cliff toes is sorted and redistributed by waves and currents. Beach topography experiences active and frequent transformations often at opposite directions. However certain zones can be distinguished where beaches are relatively stable and others dominated by beach degradation in longer terms. At some coastline sections sandy beaches become washed away completely and replaced by shore platforms armored by cobbles and boulders. In most cases such zones are associated with artificial coastal protection structures with wave-reflecting effect such as embankments walls, landslide-prevention belts or gabions.