Kuma–Manych Depression
The Manytsch lowlands (also Kuma- Manytsch lowlands; Russian Кумо - Манычская впадина, Kuma- Manytsch Valley ) is a 500 kilometer long valley between the Kuban - Azov lowland, and the Caspian Sea basin in southern Russia. The lowland forms, together with the Caspian basin, the southeastern boundary of the East European Plain.
- 4.1 See also
- 4.2 Notes and references
Location and Geology
The valley extends between the lower reaches of the Don and the northwestern part of the Caspian Sea basin. The actual valley is only 20 to 30, in the central part of only 1 to 2 miles wide. It separates the northern Jergenihügel from the south gradually increasing Stavropol ridge, which is part of the foothills of the Greater Caucasus.
The valley is named after her and the same lake system flowing river, Manytsch. To some extent, the eastern extension of the valley towards the Caspian Sea basin, respectively, of the Terek - Kuma Lowland, which is drained by the lower reaches of the Kuma, counted in the lowlands. This explains the alternative and used in Russia name, literally " Kuma- Manytsch Valley " because it meets the eastern part necessary for a dip in the geomorphological sense criterion of the surface height below sea level. The highest point of the valley is 27 m above sea level ( Lage45.71544.105 ), in a northwesterly and southeasterly direction she lowers to just above sea level, in the southeast, depending on the demarcation also slightly lower.
The Manytsch lowland located on the territory of Rostov Oblast, forms across broad segments of the boundary of the Stavropol region with the Republic of Kalmykia and reached the east, the Republic of Dagestan.
The valley is of tectonic origin. It is in the area of a depression of the earth's crust, which is accompanied by a fault zone, the southern edge of the "old" Russian platform marked and this separates from the northern Caucasus foothills, the geological already belongs to the young, alpidischen folding area of the Caucasus. Until in Quaternary Black or Azov Sea and Caspian Sea were connected again in the area of today's Manytsch lowlands, interrupted by periods of low water level of the Caspian Sea. The last time there was a connection during the so-called (early) Chwalynsker transgression of the Caspian Sea, which ended no later than 10,000 years ago.
The Manytsch lowlands as the boundary of Europe
Since Philip Johan von Strahlenberg's publication of the 1730 Manytsch lowlands in Russia and the German-speaking area is usually considered part of the geographical border between the two continents, Europe and Asia on the section between the Caspian and the Sea of Azov. This determination is based, among other things, that had once existed a connection between the Caspian and the Azov and Black Sea at the site of Manytsch lowlands. International among geographers binding definitions over the course of the boundary between the continents but there is no so in some cases the main crest of the Greater Caucasus is regarded as the limit on this section, especially in the English-and French-speaking countries. According to this view the entire Manytsch lowlands would be in Europe.
Hydrographic
The largest part of the axis of the Manytsch lowlands traversed by the two components of the eponymous Manytsch. Before the human impact of the 20th century the most remarkable part of the water of Kalaus, the coming reached the lowlands at its highest point from Stavropol ridge, where he formed a bifurcation, as Eastern Manytsch in the direction of the Caspian Sea. He reached, as well as today, the Caspian Sea is not, but got lost between small salt lakes in a semi-desert area about 100 kilometers off the coast. The lower part of the water of Kalaus flowed as Western Manytsch (or simply Manytsch ) in a westerly direction to the Don, but took in its course a large number and relatively water-rich tributaries, as the Eastern Manytsch, including the ( Great) Jegorlyk. He crossed it more salty to varying degrees and very shallow lakes: the water of medium Booth 344 km ² Manytsch - Gudilo (also Big Manytschsee, Bolshoi Manytsch, Gudilo ), the little Manytsch Lake ( Maly Manytsch, simply Manytsch; 78.8 km ²) and a further 10.7 km ², also Manytsch mentioned lake.
In the 1930s, several dams were built on the western Manytsch that form a closed chain practically over the entire course of the river: Ust- Manytschskoje near the mouth, Wessjolowskoje, and Proletarskoje at Proletarsk. The latter is the largest of the reservoirs, which also raised the previous Manytsch lakes united and its water level by several meters. On the eastern Manytsch Tschograiskoje the dam was completed in 1969, and at the same time prevented the water supply from Kalaus into the river by building a dam. The Eastern Manytsch has since been mainly by its previous tributary Tschograi and fed to 1965, built the Kuma- Manytsch channel. Below the dam, he is a significant part of the water over the Tschograi channel back towards Kuma underflow for irrigation of the intervening areas from.
Conservation
The Manytsch lowland wetland under the Ramsar Convention is one of the most significant regions of Russia, especially in ornithology. There are two Sapowednik than under nature protection areas:
- Biosphere Tschornyje Semli ( since 11 June 1990): the western, 27,600 -acre area includes part of the (former) lake Manytsch - Gudilo
- Rostowski - Sapowednik ( since 27 December 1995): one of the four sub-areas located in the west of Manytsch - Gudilo - area