Chatyr-Köl ( ; ), also Chatyr-Kul (), is a large endorheic freshwater alpine lake in the Tian Shan mountains in At-Bashy District of Naryn Province, Kyrgyzstan. It occupies the lowest part of the tectonic Chatyr-Köl Depression between the At-Bashy Range and Torugart Range, at an elevation of more than above sea level.
The lake is long and up to wide. Its surface area is about although some sources give . Its maximum depth is (or according to other measurements ), its mean depth is , and its volume is about . The shoreline is approximately long.
Geography The Chatyr-Köl basin is characterized by a weakly dissected lacustrine-fluvial accumulative plain. Most of the shoreline is low; the southern and eastern shores are predominantly marshy and include six terrace levels. Along the northern shore, where folds of Middle Paleozoic rocks approach the lake, the banks are higher and form abrasion scarps.
The lakeside plain consists mainly of Quaternary deposits of lacustrine origin and is bordered by alluvial-proluvial plains. The basin lies within a zone of widespread permafrost. Thermokarst depressions and sink-like hollows, some occupied by small lakes, as well as frost-heave mounds, gullies and bank collapses, are associated with seasonal freezing and thawing under the severe climate of the Inner Tian Shan.
Climate The mean annual temperature in the lake basin is , with mean temperature of in January, and in July. The maximum temperature in summer is , and the minimum one in winter is . Some 88-90% of the lake basin's 208–269 mm of annual precipitation falls in summer. From October to end of April the lake surface freezes, the ice becoming as much as 0.25-1.5 m thick.
Hydrology The water of Chatyr Kul Lake is yellowish-green with water transparency of up to . The mineralization of the lake ranges from 0.5 to 1.0 milligrams per liter (chloride, hydrocarbonate, sodium and magnesium type of mineralization). The salinity of the lake is 2 ppt. Mineral sources in the south part of the lake have mineralization of from per liter and pH = 5,8-6,0. Flow rate is in winter and during summer. 41 small streams debouches into the lake, of those 21 originate in Torugart Range and 20 - in Atbashy Range.
Negative water balance of the lake over the last decades causes the decline in the lake level. The mineral water from the sources is cold and has a strong mineral taste and flow first into the small Chatyr Kul lake that is about 1,5 meters higher than the actual Chatyr Kul.
Protection Since 1998, a section of the lake and its shore (3,200 ha land, 3,954 ha water) is protected as part of the Karatal-Japyryk Nature Reserve. The whole lake has been a game reserve (IUCN category IV) since 1972. The game reserve was established to protect water fowl, including the bar-headed goose. The lake is a Ramsar site of globally significant biodiversity (Ramsar Site RDB Code 2KG002).
Gallery
References