Lake Peipsi as a biggest transboundary lake in Europe

Résumé 0

Lake Peipsi sensu lato (s.l.) (Chudskoe or Chudsko-Pskovskoe in Russian) (3555 km2) is the biggest international lake in Europe and the fourth largest lake in Europe after the Ladoga, the Onega, and the Vänern with respect to surface area and is located in the Baltic Sea water basin. Three states share its water basin – the Russian Federation 59%, Estonia 34% and Latvia 7% of the basin area. The formation and distribution of the structural types of bottom deposits of Lake Peipsi is determined by hydro-meteorological (waves, currents, seasonal water-level fluctuations, lake ice impacts) as well as by the local geologic and geomorphologic factors like the topography and coastal morphology. The central part of the Lake Peipsi s.s. is 9–11 m deep; the coastal zone is shallow and the rather monotonous floor descends for some kilometres in the eastern and western coasts. The main land cover of the Lake Peipsi catchment is forest (50–70%) and agricultural lands (~30%). The water quality of the Lake Peipsi basin depends on natural processes and human activities. The trophic level of Lake Peipsi has increased step by step from mesotrophic-eutrophic to eutrophic-hypertrophic during the past decades. The main commercial fishes of Lake Peipsi are lake smelt, perch, ruff, roach, bream, pike, vendace and pikeperch. Being officially approved by the Estonian-Russian Transboundary Water Commission, the Lake Peipsi basin Management Programme forms a base for the future joint actions in the basin. River Basin Management Plan (RBMP) has been established for the shared river basin district, but separately in Estonia and Russia. Both sides notify each other regularly on the planned and implemented measures, however, the implementation of such measures is decided and done independently from each other. The management measures in Estonia should prioritize land use issues, such as a reduction of diffuse emissions from agriculture; in contrast, the Russian policy should focus on improved municipal and industrial waste-water treatment and the drinking water quality.