Sevan

Until recently, the hydronym Sevan was explained from modern arm. sowing - “black” and arm. Vank - “monastery”, by the color of the walls of the Sevanavank monastery ^[4] , built on this lake from volcanic tuff, which turned out to be folk etymology ^[5] . Decryption of cuneiform writing on a stone found on the shore of a lake dating from the 9th-6th centuries BC e., allowed to establish the origin of Sevan from Urartsk. sunia is the "lake" ^[5] .

Later ^{[6] the} lake was also called Gokcha ^{[7] [8] [9] [10] [11]} ( azerb. Göyçə ; tur . ^[6] Gökçe ^[6] ), which means “ blue water ” in Turkic languages ("Geek tea") ^[9] . The name in the form of “Gekche-deniz” is found in the 16th century manuscript of the Oguz heroic epic “ Kitabi Dede Korkut ” ^[12] . Also used was the name Sevang ^[13]

In the encyclopedia of Yuzhakov (1901), the ancient Persian name for Lake Gaoravaga is given ^[14] .

There are several legends about the origin of the name "Sevan". According to one legend, the lake was formed when one of the daughters-in-law forgot to put a lid blocking the path to the spring. Spilling around, the water began to flood the houses, leaving the residents saying: "Let the one who left the spring open become petrified." The forgetful daughter-in-law immediately turned into a stone, which can be seen on the surface of the lake under the name - Harsnakar (“daughter-in-law's stone”). According to another legend, the Vanish Armenians, forced to leave their lands, moved to the shores of Lake Sevan, reminiscent of their homeland. But they did not like the cold and harsh alpine climate. Remembering the soft and warm air of Lake Van , they exclaimed with bitterness: “The black Van (sowing the Van) went to us, the black Van!”. ^{[15] [16]}

In ancient times, Lake Sevan was located within the ancient Armenian province of Syunik and was named in Armenian Gelam Lake ^[17] , Gegham (Gelam ^[18] ) sea ^[19] ( Armenian Գեղամա ծով ), Gegharkunik ( Armenian Գեղարքունիք ) ^{[7] [20]} ), Sevanga ^[7] . In ancient Armenian sources, Lake Sevan was also called the "sea" ^{[21] [18]} . Movses Khorenatsi , an Armenian author of the fifth century , has a legend about the history of the origin of the ancient name of the lake - Gelam (Gegham). So, talking about the resettlement of the descendants of Hayk , the legendary ancestor of the Armenians , Khorenatsi writes ^[22] :

Over the years, Helam gave birth to Harma in Armavir and, leaving him to live in Armavir with his sons, he himself went to the north-east to another mountain, on the shore of one small lake. He builds up and populates the shore of the pond and gives, also he, names in his own name and this mountain - Gel, and the villages - Gelarkuni; also called the lake.

In 921, the Armenian king Ashot II Zhelezny , having strengthened himself on the island of Sevan, defeated the Arab army of the military leader Beshir on the lake, clearing the Ani kingdom from foreign invaders ^[23] . The battle went down in history as the Battle of Sevan .

The water surface of Lake Sevan is located at an altitude of about 1900 m above sea ​​level . The water surface is 1240 km² (1360 km² until the level drops), depth to 83 m.

28 rivers flow into the lake, one river Hrazdan (a tributary of the Araks ) flows out.

The lake is both tectonic and dam-like. The basin of the same name is of tectonic origin, and the dam was formed due to the outpouring of Holocene lavas ^[24] .

Sevan is surrounded by mountain ranges: from the north Pambak and Areguni , from the northeast - Shahdag ( Sevan ), from the west - Geghama , from the south - Vardenis . ^[25]

Shorzhinsky underwater rampart, Artanish peninsula and Noratus cape , protruding into the lake, Sevan is divided into two parts: Small Sevan (western) and Big Sevan (eastern). Lesser Sevan is characterized by greater depth and indented coasts. It is in this part that a larger volume of lake water is concentrated. The deepest place of Sevan is located near the foot of the Areguni ridge. In Greater Sevan, the bottom is flat, the coasts are slightly indented, and the depth does not exceed 30 meters.

Lake Sevan is freshwater, the water surface has an azure blue color. Mineralization of water up to 700 mg / l, dry residue is 0.5 g / l.

The catchment area of ​​the Lake Sevan basin 4.7 thousand km² ^[26]

Lake Sevan is the only major guaranteed source of fresh water in Armenia and the largest in the entire Caucasus . In this regard, from ancient times the question was raised about the efficient use of the lake’s water resources.

In 1848, the question was raised about the use of lake water for irrigation on the left bank of Hrazdan ^[27] .

At the beginning of the XX century there are several proposals for the use of lake waters for practical purposes. Among them - the project of descent of the lake level, proposed in 1910 by Manaseryan. It was estimated that out of the total volume of inflow, 95% of the water evaporates due to the large surface of the mirror, thus, supposedly, a significant part of the water resources simply “disappears”. It was proposed to reduce the depth of the lake by 45 meters and use the freed water resources for irrigation of the Ararat plain and generation of electricity.

Since 1923, plans have been developed for the use of water for the needs of the national economy. In 1926-1930, for this purpose, the nature of the Lake Sevan basin was studied by the Transcaucasian Commission of the USSR Academy of Sciences . Then the average level of the lake was at an altitude of 1935 m. (1927) ^[28] .

In 1931, the first scheme for lowering the lake level appeared, according to which, for 50 years, it was supposed to be lowered by 55 meters, then the perimeter would be 80 km, and the volume would be 5 km³. At the same time, a small lake with an area of ​​299 km² on the site of Small Sevan should have remained from all Sevan. The liberated area was supposed to be used for planting hazel, oak, etc.

In 1933, after the approval of the project, work began on creating artificial flow paths and deepening the Hrazdan river bed. The drains were tunnel structures at a depth of 40 meters. Since 1937, the intensive use of lake waters began. The start of operation of the Sevan-Hrazdan irrigation and energy complex served as a powerful impetus for the development of the economy of the Armenian SSR . By the end of 1933, the lake level dropped by 10 meters (1925 m.) ^[29] .

With the outbreak of World War II, work was suspended and completed only in 1949. Then every year the water level dropped by more than a meter.

A drop in the lake level, together with an increase in wastewater emissions , negatively affected the biochemical circulation of substances, led to a disruption in the normal functioning of ecosystems, which ultimately led to the process of eutrophication - an increase in the accumulation of organic substances in water from 25 thousand tons in the 1930s 150 thousand tons in 1999. Eutrophication is expressed in the periodic "flowering" of the lake and threatens to deteriorate water quality, unsuitability for use in drinking and household purposes ^[1] .

In the late 1950s, a revision of the lake level reduction project began. This was done for several reasons:

1. There were problems with the development of the liberated lands, which turned out to be completely barren .
2. It became possible to replace the hydroelectric power plants built at Hrazdan with thermal power plants , especially since the former could not satisfy the needs of the national economy of Armenia .
3. With the increasing consumption of water resources, Sevan remained the only reserve source of fresh water in the republic.

In 1961, the report of the Academy of Sciences of the Armenian SSR was published. It spoke of the need to stop the decline in the level of the lake, which had already managed to drop by 13.7 m. Due to the fact that the capacities of the Sevan-Hrazdan cascade were unclaimed, a decision was made to transfer water from the Vorotan and Arpa to the lake. It was estimated that the maximum descent of the water level will reach 18 m.

The project began in 1981, when a 48.3 km long tunnel ^{[30] [31] was built} , leading from the Kechut reservoir on Arpe to a lake near the village of Artsvanist, after which construction of the Vorotan Arpa tunnel 21.6 km long began ^{[32 ]} . In 1988, construction was suspended due to the deteriorating economic situation in the republic, and was completed only in 2003. Operation was officially launched on April 26, 2004 ^[33] .

At the beginning of 2006, the rise in water level was 41 cm compared to last year. During 2006–2010, the lake level rose by 25–35 cm per year.

In the period 2012-2016. the lake level rose by 0.36 m (on average annually by 7.2 cm), which is 0.72 m below the statutory indicator (for five years 1.08 m, annually 21.6 cm) ^[34] .

In 2018, it was reported that the ongoing repair and construction work on the Arpa-Sevan tunnel is planned to be completed in 2019. After that, the volume of water entering Sevan through the tunnel will increase by 100-150 million m³ and will reach 200-250 million cubic meters. m per year. ^[35]

On September 28, 2018, the Minister of Ecology announced that the level of Lake Sevan is 3 cm higher than in the same period in 2017. ^[36] He also assured that the operation of the Arpa-Sevan tunnel will begin in 2019, which suggests that an additional 270 million cubic meters of water can be brought to the lake. ^[37]

On May 13, 2019, the water level amounted to 1900 m 64 cm, which is 3 cm less than in the same period of 2018. ^[38]

As of 2002, nearly 35% of the territory of the Sevan National Park on 12,800 ha allocated for planting was converted into a cutting area ^[39]

On the coastal territory of Sevan there are about 4.5 thousand illegal buildings. ^[40]

In 2011, there was pollution of Sevan by sewage and heavy metals, waterlogging of the lake, the disappearance of fish stocks, changes in biodiversity and fish modification, illegal activities of mining enterprises, etc. Heritage Party MP Larisa Alaverdyan expressed concern over these problems during the parliamentary debate with by the government. Prime Minister Tigran Sargsyan redirected the issue to the Minister of Nature Protection Aram Harutyunyan, however, the latter rejected the accusations. And he said that the transparency of the water column in Sevan has increased, which is an indicator of the improvement of the lake. That soon will be built treatment plants in three cities of the Sevan basin. And that the crushing and screening complex, which Geopromineig-Gold built in Sotka, is not part of the Sevan National Park zone ^[41] .

Water fauna

Endemic fish species live in the lake: Sevan runaway (barbel) ( Barbus goktschaicus ), Sevan temples ( Varicorhinus capoeta sevangi ), Sevan trout (or Ishkhan, Salmo ischchan ).

Ishkhan was previously represented by 4 subspecies; today the subspecies of winter bakhtak and bojak have become extinct. The existence of ishkhan is at stake.

As a result of human activities, the water level in the lake decreased and the area for spawning of the Sevan trout decreased significantly. In addition to two extinct species, in 2019 another subspecies is on the verge of extinction. The fourth subspecies is cultivated at fishing enterprises ^[42] .

The genome of existing and extinct subspecies of ishkhan was sequenced, this gave information about the origin of Sevan trout from the Caspian ^[42] .

Species introduction

Whitefish ( Coregonus lavaretus ), which was imported from Lake Ladoga and Peipsi , crucian carp ( Carassius gibelio ) and narrow-toed crayfish ( Astacus leptodactylus ) ^[43] .

In 1927, 3 hatcheries worked on the lake, employing over 600 people (in the spring season), and 750 tons of fish were caught per year ^[44] . For 1928, according to the Lake Ichthyological Station, fishing was estimated at 475–690 tons per year ^[45] .

90% of commercial fishing in Armenia is carried out on Lake Sevan and in some years amounted to 2000 tons. ^{[46] The} fish stocks of Lake Sevan in 2002 were estimated at 36 million drams. ^[47]

Before the descent of the lake level, the main commercial species were trout , kogak , and after the descent of the level - whitefish , silver carp ^[46] . On the lake shore, fish farms were created for the artificial breeding of trout. In Lake Sevan, Ishkhan is in danger of extinction.

Birds

In the basin of Lake Sevan, the Sevan National Park has been created with four reserves and ten reserves . The lake is an important population center for the Armenian gull ( Larus armenicus ), the number of which reaches 4000-5000 pairs. Other birds staying on the lake are the American swan ( Cygnus columbianus ), piscule ( Anser erythropus ), red-nosed duck ( Netta rufina ), white-eyed dive ( Aythya nyroca ) and black-headed laughter ( Larus ichthyaetus ).

A significant part of the territories (about 17 thousand hectares) liberated due to the descent of the lake level is covered with artificial plantations, which are communities of pine , poplar , goof, sea ​​buckthorn and a number of other trees and shrubs. In the buffer zone, juniper , rosehip , mountain ash , and barberry grow from natural tree-shrub species. There are many astragals and acantholimons, among which there are a number of rare and endangered species. In the Sevan basin, the natural residual islets of oak , hornbeam , maple , juniper, and mixed communities have also been preserved ^[48] .

Of the historical monuments, the most famous is Sevanavank Monastery, located on a peninsula near the city of Sevan in the northwestern part of the lake. Initially, the monastery was located on the island, but due to the lowering of the water level an isthmus was formed that connected the island with the land. Another monastery located on the western slope is Ayrivank . In the village of Artsvanist on the shore of the lake there is a monastery of the 10th century Vanevan. On the shore of the lake is the village of Noraduz , known for the largest cemetery of khachkars , numbering about 900 khachkars of different eras and styles. Khachkars are also in the village of Nerkin Getashen on the south coast. After lowering the water level, numerous archaeological artifacts with an age of 2000 years or more were discovered (some of them from the Bronze Age ). Most of these artifacts are in museums in Yerevan . On the western shore of the lake is a helipad .

Under the guidance of experienced sea captain Yervand Gasparyan, who moved to Armenia in 1921, the engineering structures necessary for navigation, including several marinas, were built along the banks of Sevan. Shipping for the transport of goods and passengers was organized on the basis of several small motor boats purchased in the Caspian shipping company and in Batumi . Due to the increase in traffic, more thorough vehicles were required. The hull of the ship with a displacement of 1230 tons was assembled on a temporary slipway in the courtyard of the Armenian engineering plant in May 1934. The final assembly was carried out on slipways on the shore of Sevan, in 1935 the ship "Mikoyan" was handed over to the shipping company and served until the liquidation of shipping due to lowering the water level in the lake.

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  Traditional sailing boats of Lake Sevan. Reconstruction

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  Beachfront hotel with adjoining beach

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  View of Sevan from Sevanavank Monastery

On July 26, 2012, at the bottom of Sevan, at a depth of about 16 meters, a sunken 18-meter wooden ship was discovered. According to the discoverers, part of the find was preserved almost entirely, another part was damaged. It is planned to carry out underwater excavations at the ship’s location ^[49] .

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  “Lake Sevan on a rainy day” G. Bashinjaghyan , 1899.

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  Sevanavank Monastery.

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  Ayravank Monastery , IX — XIII centuries

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  The medieval cemetery of Noratus on the lake.
  X — XVII centuries

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  Vanevan, X century

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  Kotavank. Founded by Prince Grigor Supan II of the Haikazun clan

• Transcaucasian Commission of the USSR Academy of Sciences

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• The program of annual and comprehensive measures for the restoration, protection, reproduction and use of Lake Sevan / RA Law of December 14, 2001 (in Armenian)
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• Chilingaryan L.A., Mnatsakanyan B.P. Forecast of an increase in the level of a large reservoir lake over many years (for example, Lake Sevan) // Sat. doc. Int. congress "ETEVK"; May 24-27, 2005. - Yalta, 2005 .-- S. 515-518.
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• Chilingaryan L.A., Mnatsakanyan B.P. Assessment of changes in the water balance of Lake Sevan with a decrease in its level // Water: Ecology and Technology EQUATEK-2008. - M. , 2008 .-- S. 94 . Archived December 16, 2012.
• Babayan G.G., Aghababyan K.A. Modern ecological state of water bodies of the Republic of Armenia // Water Resources. - M., 2008. - T. 35, No. 2. - S. 245-250.
• Babayan G.G., Aghababyan K.A. About some reasons of deterioration of water quality of Lake Sevan at present // Water supply and sewage. - 2009. - No. 1 . - S. 9-15 . Archived December 16, 2012.

• Some materials on the ecology of Lake Sevan (1998-2001) (neopr.) . Date of treatment February 18, 2006. Archived December 16, 2012.