Abrasion of the Lithuanian Sea coast

摘要

The most of Lithuania's coast (approx. 92 km) is being eroded by the Baltic Sea. Accumulation is observed only during calm periods. Lithuania's coastal area can be divided into two different zones. The peninsula Kurshiu Spit which has fine sandy beaches, unique nature and where there are no hydrotechnical constructions. It's used for rest resorts, tourism. The other zone, that is the continental part, mostly with sandy beaches too is used not only for rest and health, but for different economical purposes as well. The piers of Klaipėda Port, a former port of řventoji and the groyne near the promenade pier of Palanga partly stabilize the seashore. Time from time the beaches and the foredunes suffer great damages made to them by hurricanes and strong gales. The 4.5 km length morainic cliffs are attacked by waves. Far more actively they are damaged by suffosian processes. Strong hurricanes with the highest rise of the water level were most catastrophic for the coast in the period of the previous 40 years. During the hurricane “Anatoly” (December 1999) the coast lost about 55 hectares of the foredunes or shore. The next hurricane “Earwin” (January 2005) caused the loss of about 13.5 hectares. All the coastal zone is under systematic monitoring control by the Center of Marine Research of the Environmental Ministry. The collected field data revealed that abrasion of the coast of the continental part is by 2-3 times more intensive than that in the peninsula zone. It depends on different management of them. During the 19-20 centuries a 10-20 m high foredune, streching along the seacoast, was built. Its western slope was covered with specific plants such as European beach-grass (Ammophila arenaria) which is one of the best species to strengthen the sand cover and protect it from drift. The seashore of the continental part lost most of the foredune. The rest of it is planted by 2-3 times less than- it is on the Kurshiu Spit coast. The main abrasion focus (to 7 meters per year) formed near Palanga where the groyne, which earlier stabilized the coast, was destroyed. Currently the groyne replacing the part of the destroyed one was constructed thus enabling a partial restoration of the beach zone. But the width of the beach zone is still significantly lesser than the one observed in nineties of 20 century.