Kotra River

Infobox River
river_name = Kotra River


caption =
origin = 22 km southeast from Varėna
mouth = Neman River
basin_countries = Belarus, Lithuania
length = 109 km
elevation =
mouth_elevation =
discharge = 12.8 m³/s
watershed = 2010 km²

Kotra River ( _lt. Katra) is a 109 km length river in Belarus and Lithuania. It is an interesting river due to a rare phenomenon of river bifurcation. At first Kotra and Ūla Rivers form one river sometimes known as Pelesa River. Pelesa starts in Belarus and flows in northwest direction. Just passed Belarus-Lithuania border, between Paramėliai and Kazliškės villages situated some 22 km southeast of Varėna, it branches out into two independent rivers: Kotra, tributary to the Neman River, and Ūla, tributary to the Merkys. Such situation developed in the second half of the 19th century when Ūla due to its channel erosion crossed the water divide between its own and Kotra drainage basins. As a result Ūla enlarged its basin by some 410 km². Two of former Kotra tributaries now carry their water to Ūla. Also, these processes have caused the decrease of the groundwater level and almost total disappearance of several large lakes located in the site.

Kotra flows in southwest direction along the Belarus-Lithuania border for 24 km and the remaining 85 km through Belarus. Kotra flows along the southern border of Čepkeliai Marsh, an area protected as nature reserve. With the changes in drainage basins and groundwater levels some 20 km² of open marshes overgrew with trees. Kotra and surrounding marshes form wetlands of international importance. Varėna district municipality established a 1.085 km² reservoir to protect natural Kotra environment.

References

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* " [http://www.ekoi.lt/info/lter/cepkeliai.htm Cepkeliai] ". "Long Term Ecological Research (LTER) Network in Lithuania". Institute of Ecology of Vilnius University. Accessed 9 October 2006.

External links

* [http://www.wetlands.org/RSDB/_COP9Directory/Directory/ris/3BY004en.pdf Information Sheet on Ramsar Wetlands (PDF)]
* [http://www.ekoi.lt/uploads/docs/AZL_2005_2_173-178psl.pdf Environmental Changes in the Ūla and Katra Upper Reaches During the Last 14,000 Years (PDF)]
* [http://www.ekoi.lt/info/lter/cepkeliai.htm Čepkeliai Marsh and Kotra River]