Особенности литодинамики галечных пляжей южного берега Крыма

Abstract

The results of the study of the peculiarities of lithodynamics of pebble beaches of the South Coast of Crimea based on the long-term monitoring of the state of beaches performed at the Black Sea Hydrophysical Subsatellite Proving Ground of the Marine Hydrophysical Institute of the Russian Academy of Sciences in the settlement of Katsiveli are presented. Long-term changes of the beach of Limensky Bay since 1950 and of beaches of the shore protection structures since 1988 are characterized. The volume of income and outcome of pebbles during the change of wind-wave regimes was estimated by the example of Limensky Bay beach and the artificial beaches of the coast protection structures in the coastline section from Katsiveli to Ponizovka settlement. The most influential factor in the formation of the pebble beaches of the Southern Coast of Crimea is the change in alongshore wind-wave regimes in the “days-months” time scale, which leads to significant fluctuations in sea level near the coast and a corresponding change in the directions of the bottom current velocity components perpendicular to the shoreline. The largest expense and income of beach-forming material (up to 1 m3/day per linear meter of beach) occurs during storms, respectively, with wind-wave regimes of the eastern and western directions. The largest irreversible removal of the mass of beach-forming materials during the change in wind-wave regimes occurs from the eastern and central sections of the bays and artificial beaches of coastal protection structures, and partial restoration of beaches—on their western sections. Natural underwater reefs in the coastal waters of bays and artificial beaches of shore protection structures contribute to the preservation of beaches in them. The reason for the gradual average long-term degradation of beaches may be the predominance of eastern storm winds over western ones in conditions of blocking the natural income of beach-forming materials from the coast by the coastal infrastructure objects.