Frøylandsvatnet
Encyclopedia
Frøylandsvatnet is a lake
located in the district of Jæren
in Norway
. It forms part of the division line between the municipalities of Klepp
and Time
. The origin of the name is from the Norse god Frey. The lake is quite shallow, with an average depth of 5.5 m.
The town of Bryne
, and the villages Klepp stasjon
and Kvernaland
are all located close to the lake.
The lake is located in an area with very intensive agriculture
. Early in the 1980s the lake was identified as being one of the worst cases of eutrophication
in Norway. Algal bloom
was a widespread problem, and there were cases reported of poisonous algea causing cattle to die from drinking the water.
The release of substances containing nitrogen
and phosphorus
has since been reduced, but large collections of sediment
in the shallow lake causes the problems to decline rather slowly.
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
located in the district of Jæren
Jæren
Jæren is a traditional district in the county of Rogaland. The others are Dalane, Ryfylke and Haugalandet.Jæren is the largest flat lowland area in Norway, stretching from the municipality of Randaberg in the north to Hå in the south. The coast is flat compared to the rest of the Norwegian coast,...
in Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
. It forms part of the division line between the municipalities of Klepp
Klepp
Klepp is a municipality in Rogaland county, Norway. The parish of Klep was established as a municipality on 1 January 1838 ....
and Time
Time, Norway
Time is a municipality in Rogaland county, Norway. It is part of the region of Jæren. The administrative centre of Time is the town of Bryne.-Name:...
. The origin of the name is from the Norse god Frey. The lake is quite shallow, with an average depth of 5.5 m.
The town of Bryne
Bryne
Bryne is a city, located in, and the administrative centre of, the municipality of Time, Norway. Bryne is located about 25 minutes south of Stavanger by train. The area of Bryne is 4,79 km²....
, and the villages Klepp stasjon
Klepp stasjon
Klepp stasjon is a village in the municipality of Klepp, located in the county of Rogaland, Norway. It is located by lake Frøylandsvatnet.When the Jærbanen railway was constructed in 1878, the administrative centre of Klepp was somewhat offset from the convenient path of the railway, so the...
and Kvernaland
Kvernaland
Kvernaland is a village in Rogaland, Norway. The village is located by lake Frøylandsvatnet, right at the division between municipalities Klepp and Time. Of its total population of 5,454, 3,153 reside in Klepp and 2,301 in Time. Several factories, mainly producing equipment for agriculture, are...
are all located close to the lake.
Environmental issues
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
. Early in the 1980s the lake was identified as being one of the worst cases of eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...
in Norway. Algal bloom
Algal bloom
An algal bloom is a rapid increase or accumulation in the population of algae in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration...
was a widespread problem, and there were cases reported of poisonous algea causing cattle to die from drinking the water.
The release of substances containing nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
and phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
has since been reduced, but large collections of sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
in the shallow lake causes the problems to decline rather slowly.