Lake Bohinj - Slovenia

Lake Bohinj is of tectonic-glacial origin and was transformed by the Bohinj glacier. Its surface area is 3.28 km 2 , its volumeWeather conditions and chlorophyll concentrations determine long-term macrophyte community dynamics of Lake...92.5 × 10 6 m 3 and its maximum depth 45 m. It is located at an altitude of 525 m a.s.l. and issurrounded by mountains that are up to 2000 m high. Lake Bohinj is conditioned by the main inflow from River Savica and by several karst springs from the base of Mount Komarča and has a single outflow, River Sava Bohinjka. The residence time of the water in Lake Bohinj is about 4 months, which means that the total volume of the water in Lake Bohinj changes three times a year. The surrounding watershed comprises around 94.3 km2 and is mostly uninhabited, with a large portion extending above the tree line; therefore, the input of nutrients into Lake Bohinj is moderate. This watershed receives about 3300 mm of rainfall a year. Long-term temper-atures show a tendency to a rise. In winter, usually in January, the surface water cools and the lake can be frozen over. From 1961 to 1990, Lake Bohinj was frozen over for a mean of > 50 days/year, while in the decade from 1991 to 2000, the mean number of days with ice cover was reduced to 31 days/year. Since 1990, the lake did not freeze completely in individual years. The majority of the lake catchment area consists of carbon-ate rock, and therefore, the main lake sediment fraction is carbonate, while quartz and feldspar represent a minor part.