BUILDING TOGETHER OUR TERRITORIES LIMNOLOGY, LAKE BASINS, LAKE WATERS
Petre GÂŞTESCU Valahia University, Târgovişte
Limnology. There are two ways of interpreting the term limnology: The science which studies lakes (its name comes from the Greek 'limnos' which means 'lake', 'swamp', 'pond'). Lakes can be classified , according to lake basin genesis, water thermal and chemical .regime, development of floral and faunal associations, relationships with the environment and usefulness for humans.
Limnology is a border discipline between geography, hydrology and bi- ology, and is also closely connected with other sciences, from it borrows re- search methods. Physical limnology (the geography of lakes), studies lake biotopes, and biological limnology (the biology of lakes), studies lake biocoe- noses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904), which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuchandbuch der Seenkunde: allgemeine Limnologie,(1901). Since both the lake biotope and its biohydrocoenosis make up a single
whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems), a micro- cosm in itself, as the American biologist St .A. Forbes put it (1887). Second, limnology is science which studies the biology of continental
waters, that is of running waters, stagnant waters and springs, either fresh, brackish or saline. It is, in effect, a subdivision of hydrobiology. The promoters of this study trend were Aug. Thienemann and E. Naumann, who in 1922 had founded the Societas Internationalis Limnologiae (SIL) at Kiel in Germany. This society, which gathers remowned specialists in the field, organizes inter- national congresses every 3 years. Classification of lakes basins. The lake is a relatively stagnant stretch
of water which fills a ground depression. From this point of view, a lake con- sists of two distinct parts - the basin and the water body. Lakes may have a very wide range of surface areas,from a few thou-
sands of square meters to hundreds of square kilometers (e.g. the Caspian Sea, the largest lake in the world, 371,000 sq km). Natural lakes cover some 2.7 million
sq.km ( 1.8 % of the Earth’s surface),encompassing a water vol- ume of about 176 400 cubic kilometers ( 0.013% of the planetary water vo-
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