Aeolian processes and forms development on coasts of Ukraine

Abstract

The length of the Black and Azov Seas within Ukraine are 2835 km, from the Danube delta in the West to the Kryvaya spit in the East. Aeolian processes and relief forms are spread on sandy spits, barriers, terraces. They occupy almost 703 km of Ukrainian shore length, or 43.2% in total. Acute sediment deficit and prevailing of seaward winds by energy determine the small size of aeolian forms, their spreading as separate hearths and discontinuous ridges. As spits and barriers are very narrow (up to 100-250 m), aeolian forms being very low (usually 1-2 m, maximum not over 5 m high). During gales, 1-2 times a year waves overflow the spit or barrier on their dorsal side. Such phenomenon determines very close interaction of all elements on accumulative form surface, in contrast to these coasts where dunes are high and of great width. Besides the total sediment deficit, direction of prevailing winds and accumulative forms sizes, aeolian processes are influenced by composition and humidity of sediments, thickness of dry sand layer, density and height of vegetation, the distance of wind momentum over sandy surface, duration and reoccurence of wind action. Sediment supply in the coastal zone very often does not influence the size of coastal dunes: retreating shores can have in themselves bigger shore dunes than accumulative ones.