Lake Cerknica

Lake Cerknica Cerkniško jezero
With the summit of Slivnica in the background (winter)
Location	Inner Carniola
Coordinates	45°44′59″N 14°22′20″E / 45.74972°N 14.37222°E / 45.74972; 14.37222Coordinates: 45°44′59″N 14°22′20″E / 45.74972°N 14.37222°E / 45.74972; 14.37222
Lake type	intermittent
Basin countries	Slovenia
Surface area	38 km² (max.)
Average depth	10 m (max.)
Surface elevation	546 m to 551 m
Settlements	Cerknica, Dolenje Jezero, Gorenje Jezero, Grahovo

Lake Cerknica (Slovene: Cerkniško jezero, German: Zirknitzer See) is an intermittent lake near Cerknica in Inner Carniola, a region of Slovenia. When full, it is the largest lake in the country. It lies in the southern part of the Cerknica Polje. The surface of the lake can reach up to 38 km² and the surface level varies from 546 to 551 metres above sea level.

Lake Cerknica is an important wildlife resort, especially as a nesting place for many bird species. It is therefore a part of two Natura 2000 areas of protection^[1] and is the focus of the Inner Carniola Regional Park which covers additional Natura 2000 areas in the broader region.^[2]

Intermittent behavior

It lies in a depression of the limestone plateau known as the Karst, and exhibits some of the most remarkable features of Karst phenomena. The lake, which under ordinary conditions has an area of about 10 square miles (26 km²) and a mean depth of 20 feet (6.1 m), communicates through a number of openings with a series of subterranean reservoirs or caverns, some of which are above the lake level in the surrounding hills. In the autumn, when the rainfall is slight, the lake is completely drained into the reservoirs lying below its level, and its bed is speedily covered with rich vegetation. With the returning heavy rains, the surrounding higher reservoirs are filled and discharge suddenly through the subterranean passages into the lake, so that the latter very rapidly regains its ordinary volume and may even inundate the surrounding country. The changes in level are, however, very irregular. Sometimes the lake does not disappear for several years, and it can remain dry for over a year, as it did in 1834-35. It is rich in fish, which disappear and return with the water.^[3]

Research history

Strabo in his Geography (v. 7, ch. 5) mentions a "marsh called Lugeum" (helos Lougeon kaloumenon) which has been identified with Lake Cerknica,^[4] Lougeon being Strabo's Greek rendition of a local toponym, perhaps of Illyrian origin. It is Romanized as Lugeum. In 17th century, the Carniolan polymath Janez Vajkard Valvasor described the lake in his letter to the Royal Society which was later published in society's Proceedings. He proposed a model of filling and emptying the lake, based on Descartes' mechanics.^[5]

References

1. ^ Projektno območje. Project Life. Notranjska Regional Park. Accessed 2009-12-16. (in Slovene)
2. ^ Notranjska Regional Park - informative leaflet. Accessed 2009-12-16.
3. ^  "Zirknitzer See". New International Encyclopedia. 1905. 
4. ^ Strabo, Geography, v. 7, ch. 5 at perseus.tufts.edu
5. ^ Weichard, John (1686-1692). "An Extract of a Letter Written to the Royal Society out of Carniola, by Mr. John Weichard Valvafor, R. Soc. S. being a Full and Accurate Description of the Wonderful Lake of Zirknitz in That Country". Philosophical Transactions (1683-1775) 16: 411–427. JSTOR 101905. 

External links

• Cerknica Lake at official Slovenia travel guide