Coastal erosion Lithuania
Lithuania has an about 92 kilometer long coastline of the Baltic Sea. It is a complex area including terrestrial and marine features: sandy beaches, dunes, fens, inshore waters and an underwater slope, a few moraine cliffs (3). The area of the Curonian Lagoon is about 1584 km2. The Lagoon is a semi-enclosed almost fresh water body, which is separated from the sea by a narrow sandy spit (minimum width is about 400 m). About 26% of the Curonian Lagoon area belongs to the Lithuanian Republic, the other part to the Russian Federation. The length of the Lithuanian part of the Lagoon coastline is about 150 km (1,3).
The northern part of the Lithuanian coast currently experiences rapid erosion, reaching 60-70 m during the last 70-80 years in some sections (2). The southern part of the Lithuanian coast is stabler and accumulation has reached up to 80-90 m during the last 100 years (8). The length of the eroding coastline has increased from 18 to 27% between 1990 and 2003. The proportion of the accreting coast fell from 40 to just 12% over the same period. Port development and recreational activities are among the most important factors causing coastal erosion. Also, acceleration of sea level rise has been observed on the Lithuanian coast (9). Between 1970 and 2000, Baltic Sea level rose by more than15 cm (10). Rising sea level and more frequent winter storms will determine the more frequent floods in the coastal zone (especially on the River Nemunas delta); destruction of the Baltic sea shores and the degradation of dunes will grow stronger, average height of waves will keep growing bigger (4).
The strength of erosive processes on the sandy south coasts of the Baltic Sea is enhanced with the lengthening of the ice-free period. It has also been seen that the number of strong storms is on the rise. Lithuania for example has experienced 10 storms previously considered as ‘once in a hundred years events’ during the past 50 years! (5). In addition, significant changes in wind direction along the Lithuanian coast have been observed that have led to enhanced occurrence of southwestern waves being one of the causes of more intensive erosion of the Lithuanian coast (7).
All countries along the southern Baltic seashore suffer from coastal erosion (6):
- In Denmark, the most visible erosion has taken place at capes and cliffs, with cliff erosion amounting to 0.2–0.5 m/year on average.
- On the German coast, major erosion takes place at capes and cliffs in the region of Kiel Bay (on average, 0.3–0.4 m/year), on the islands of Rügen and Usedom, and east of Rostock.
- On the Polish coast, the average coastal retreat in the period 1875–1979 was 0.12 m/year, increasing to 0.5 m/year in the period 1960–1983, and 0.9 m/year in 1971–1983. Erosion processes are now present over 74% of the Polish coast. Owing to this, coastal defense structures have been erected along 26% of the Polish coast.
- In Latvia, over the past 50–60 years, long-term cliff erosion has occurred at the rate of 0.5–0.6 m/year, reaching a maximum of 1–1.5 m/year along certain stretches of the coast. Since 1980/1981, the rates of erosion along the Latvian coast have increased to 1.5–4 m/year. A similar situation has also been observed along the coast of Lithuania.
- In Estonia, there has been increased activity of both erosion and accumulation processes in recent decades.
Hard constructions are limited. Beach and nearshore nourishments are being used to restore the sand balance disturbed by the port breakwaters (1).
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Lithuania.
- Tonisson et al. (2013)
- Gudelis (1998), in: Tonisson et al. (2013)
- Dailidiené et al. (2006)
- Republic of Lithuania (2010)
- Haanpää et al. (2007)
- HELCOM (2007)
- Kelpšaitė and Dailidienė (2011)
- Gudelis (1995), in: Tonisson et al. (2013)
- Jarmalavičius et al. (2007), in: Tonisson et al. (2013)
- Johansson et al. (2001); Dailidienė et al. (2006), both in: Tonisson et al. (2013)