Lake level
The term lake level describes the average height of the water surface of a standing body of water ( water level in still water ). A lowering of the same can be caused or accelerated by lack of precipitation , as for example in the Aral Sea or by climate changes . However, this can fluctuate due to natural inputs such as precipitation or snowmelt or as a result of deliberately undertaken interventions such as damming or lowering of the water level to gain agricultural land. An example of the latter is the Great Plön Lake during the 19th century .
Similar, unnatural changes in the lake level are observed in dams or reservoirs , where the water level can be artificially regulated. Therefore, the maximum water height is generally referred to here with the term storage target .
It should also be taken into account that the reference level of the measurement may be slightly different depending on the country. While in Germany the height of the lake is given in "meters above sea level " with reference to the Amsterdam level , in Austria the height is in " meters above the Adriatic " - measured at the Molo Sartorio in Trieste - and in Switzerland " meters above sea " with the reference point Repère Pierre du Niton , a measuring point on a rock in Lake Geneva near the port of the city of the same name .
Information sheet lake level
There is also an information sheet of the same name that focuses on Lake Constance . It appears twice a year in June and December and is published by the International Water Protection Commission for Lake Constance (IGKB).
literature
- François Alphonse Forel: Handbook of Seenkunde / General Limnology. Engelhorn publishing house, Stuttgart 1901