Lake Sevan

Lake Sevan
Aerial view of the lake
Lake Sevan is located in central eastern Armenia
Location	Gegharkunik Province, Armenia
Coordinates
Primary inflows	28 rivers and streams
Primary outflows	evaporation: 85-90%, Hrazdan River
Basin countries	Armenia
Managing agency	Ministry of Nature Protection
Max. length	74 km (46 mi)
Max. width	32 km (20 mi)
Surface area	1,242 km2 (480 sq mi) (2009)
Average depth	25.9 m (85 ft) (2009)
Max. depth	79.4 m (260 ft) (2009)
Water volume	32.8 km3 (26,600,000 acre·ft) (2009)
Salinity	0.7%
Surface elevation	1,900.19 m (6,234.2 ft) (2012)
Islands	formerly 1 (now a peninsula)
Sections/sub-basins	2 (Major Sevan, Minor Sevan)
Settlements	Gavar, Sevan, Martuni, Vardenis

Designations
IUCN Category II (National Park)
Official name	Sevan National Park
Designated	14 March 1978
Ramsar Wetland
Designated	6 July 1993

Lake Sevan (Armenian: Սևանա լիճ, Sevana lič̣) is the largest body of water in Armenia and the Caucasus region. It is one of the largest freshwater high-altitude lakes in Eurasia. The lake is situated in the central part of Armenia, in the Gegharkunik Province, at the altitude of 1,900 m (6,200 ft) above sea level. The total surface area of its basin is about 5,000 km² (1,900 sq mi), which makes up 1/6 of Armenia's territory. The lake itself is 1,242 km², and the volume is 32.8 billion m³. It is fed by 28 rivers and streams. Only 10% of the incoming water is drained by the Hrazdan river, while the remaining 90% evaporates.

Sevan provides some 90% of the fish and 80% of the crayfish catch of Armenia. It has significant economic, cultural, and recreational value. Its only island (now a peninsula) is home to a medieval monastery.

Sevan was heavily exploited for irrigation of the Ararat plain and hydroelectric power generation since the 1930s. Consequently, its water level decreased by around 20 meters and its volume reduced by more than 40%. Two underground tunnels were later built to divert water from highland rivers, which halted its decline and its level began rising. Before human intervention dramatically changed the lake's ecosystem, the lake was 95 m (312 ft) deep, covered an area of 1,416 km² (5% of Armenia's entire area), and had a volume of 58.5 km³. The lake surface was at an altitude of 1,916 m above sea level.

Etymology

Origins of Sevan

Sevan is thought by scholars to have originated from the Urartian word suinia or suinna or sunia ("lake"), which is found in an inscription left by the Urartian king Rusa I. The cuneiform inscription from the 8th century BC was found in Odzaberd, in the southern shore on the lake.

There are at least two popular versions of origins of the word "Sevan". According to one, Sevan comes from the Armenian words sev (black) and vank’ (monastery), referring to the island monastery. The second version links Sevan's name with that of Lake Van. It is said that long ago, Armenians came from the areas around Lake Van to Lake Sevan. They saw that the lake was dark and almost black yet reminded them of Van, therefore the lake was called sev ("black") + Van.

Other names

• Since antiquity up to the Middle Ages, Sevan was mostly known as a sea and referred to in Armenian as the Sea of Gegham (Գեղամա ծով, Geghama tsov). The name is mentioned by several medieval Armenian historians, including in Movses Khorenatsi's History of Armenia (ծով Գեղամայ).
• In the classical antiquity, the lake was known as Lychnitis in Latin and Greek (Λυχνῖτις). It is mentioned in Ptolemy's map of Greater Armenia in his Geography.
• The historic Georgian name of the lake is გელაქუნი, Gelakuni. It is called "Lake Ereta" by Leonti Mroveli in The Georgian Chronicles drawing from the name of its old inhabitants (i.e. before the fall of Urartu), the Èrs.
• At least from the early modern era, the lake was often referred to as Gokcha (from Turkish Gökče, which translates to "blue water"). Besides being used by the Azeri population (Azerbaijani: Göyçə), the name Gokcha appeared in Russian and European sources until the early twentieth century.
• Russian and European sources of the nineteenth and early twentieth century referred to the lake as Sevanga.

Significance

Cultural

Along with Lake Van and Lake Urmia, Sevan is considered one of the three great "seas" of historic Armenia. It is the only one within the boundaries of present-day Republic of Armenia, while the other two are located in Turkey and Iran, respectively. Lake Sevan is considered the "jewel" of Armenia and is "recognized as a national treasure" in the country. The 2001 Law on Lake Sevan defines the lake as "a strategic ecosystem valuable for it environmental, economical, social, scientific, cultural, aesthetic, medical, climatic, recreational, and spiritual value." German naturalist and traveler Friedrich Parrot, who with the renown Armenian writer Khachatur Abovian conquered the summit of Mount Ararat in 1829 for the first time in history, wrote that the "sea enjoys a high celebrity for sanctity with all Armenians, far and near, on account of the many old, and now partly deserted religious houses on its shores; and with all the rest of the natives for its wonderful stores of fish, of which salmon-trout is peculiarly esteemed, being dried and carried to great distances for sale."

Economic

It is important for the Armenian economy: being the main source of irrigation water, Sevan provides low-cost electricity, fish, recreation, and tourism.

Origin

Sevan originated during the early Quaternary when a Palaeo-Sevan, ten times larger than the present lake, came into existence by tectonic formation. The current lake was formed some 25 to 30 thousand years ago.

Human intervention

Exploitation and reduction

Background

Sevan was recognized as being a major potential water resource in the 19th century. Its high attitude location relative to the fertile Ararat plain and limited energy resources attracted engineers to explore ways of usage of the lake's water. In his 1910 book, Armenian engineer Sukias Manasserian proposed to use Sevan's water for irrigation and hydroelectric power generation. He proposed draining the lake by 50 meters. Major Sevan would completely dry out, while Minor Sevan would have a surface of 240 km².

Implementation

Manasserian's proposal was adopted by the Soviet authorities in the 1930s when, under Joseph Stalin, the country was undergoing rapid industrialization. Works on the project started in 1933. The riverbed of Hrazdan was deepened thorough excavation. A tunnel was bored around 40 metres (130 ft) under the lake's surface. The tunnel was completed in 1949 and thereafter the Sevan's level began to drop significantly, at a rate over 1 meter per year. The water was used for irrigation and the Sevan–Hrazdan Cascade of six hydroelectric power stations on Hrazdan River.

Hydrometric indices of Lake Sevan before and after intervention

Indices	1930	2009
Height above sea level, m	1915.89	1896.46
Lake surface, km²	1416	1242
Mean depth, m	41.3	25.9
Maximum depth, m	98.7	79.4
Water amount, km³	58.5	32.8

Effects

During the second half of the 20th century, the ecological condition of Lake Sevan underwent tangible changes and vast degradation due to reduced water level, increased eutrophication, and detrimental impact of human activity on the biological diversity of the lake. According to Babayan et al. the lake level dropped by 19.88 m by 2002, while the volume decreased by 43.8% (from 58.5 to 32.9 km³). Due to the water level decrease, the quality of the water deteriorated, natural habitats were destroyed that meant loss of biodiversity. Vardanian wrote that drop of the lake level and the economic development in the basin brought about the change in hydro-chemical regime of the lake. The quality of the water deteriorated, water turbidity increased. The inner circulation of the water constituents as well as the circulation of the biological substances altered.

Reversal and recovery

According to Babayan et al. "by the 1950s it had become evident that the ecological and economic consenquences of extensive exploitation of the water of Lake Sevan were too undesirable to continue in the same way."

Map showing the two tunnel bringing water to the lake and the Hrazdan River and the six hydroelectric power stations built on it.

Arpa-Sevan tunnel

In 1964 a project began to divert the Arpa River (from a reservoir near Kechut) through a 49 km long tunnel to to the lake near Artsvanist. The tunnel, called Arpa-Sevan, was completed in 1981. It brings up to 200 million m³ of water to Sevan per year.

Vorotan-Arpa tunnel

Since the water level in the lake did not rise as fast and as much, on 20 April 1981 the Council of Ministers of the Soviet Union made a decision for the construction of the "Vorotan–Arpa" tunnel. This 21.6-km tunnel was begun from the Spandarian Reservoir on Vorotan Riverm further south from Kechut. Due to the Nagorno-Karabakh conflict and the 1988 earthquake in northwestern Armenia construction was halted. The tunnel was inaugurated on 26 April 2004. The Vorotan-Arpa tunnel bring an additional 165 million m³ to the lake annually.

Increase in water level

After the construction of the two tunnels the water level began rising significantly since the mid-2000s. In 2007 it was reported that the water level rose by 2.44 meters in the last 6 years. It reached 1900.04 in October 2010. The government committee on Sevan predicts that the level will reach 1903.5 by 2029.

Population

Armenia's Gegharkunik Province shown in red

The Gegharkunik Province, which roughly corresponds to the lake's basin, had a de facto population of 211,828 according to the 2011 Armenian census. The largest settlements in the province are: Gavar (20,765), Sevan (19,229), Martuni (12,894), Vardenis (12,685), Vardenik (9,880), Yeranos (6,119), Chambarak (5,660), Lchashen (5,054), Tsovagyugh (4,189).

Tourism

Beaches

Lake Sevan has the only beaches in Armenia. They are a popular destination for the Armenians. Sevan's beaches provide a unique experience within the landlocked country for Armenians. The beaches adjacent to hotels are usually privatized. Numerous beaches are located along the entire lake shore. The most popular of them is a 2.5-km stretch on the northern shore, extending northwest from the peninsula. Resorts include Harsnaqar Hotel, Best Western Bohemian Resort, and numerous smaller facilities. Activities include swimming, sunbathing, jet skiing, windsurfing, and sailing. The area also includes numerous campgrounds and picnic areas for daytime use. A less-developed beach destination stretches along the eastern shore from Tsovagyugh to Shorzha, with numerous small cabins at Shorzha. The Avan Marak Tsapatagh Hotel, a Tufenkian Heritage Hotel, is a luxury resort on the undeveloped southeastern shore of the lake near Tsapatagh.

The Armenian government pledged to "reduce the growing commercialization of rest at Lake Sevan that makes it unaffordable for most citizens struggling to find other beach options during hot Armenian summers." In 2011 the government established public beaches in the Sevan National Park’s recreational zone. The first two public beaches were opened in July. Some 100,000 people visited the public beaches in summer of 2011. The beaches have free parking space, children’s and sports playgrounds, toilets, medical aid stations, and rescue services. They are also equipped with beach couches. By 2014, the number of public beaches reached 11. Some 200,000 people took holiday there in 2014.

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  Best Western Bohemian Resort

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  Sevan city beach

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  The Harsnaqar Hotel Complex

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Sites of interest

The most famous cultural monument is the Sevanavank monastery located on the peninsula, which was until the mid-20th century an island. Another prominent monastery at the western shore is Hayravank, and further south, in the village of Noratus, is a field of khachkars, a cemetery with about 900 khachkars of different styles. Additional khachkars are found at Nerkin Getashen on the south coast.

Island

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Fauna

Fish

Sevan trout (Salmo ischchan) is an endemic species of the lake, but it is endangered as some competitors were introduced into the lake, including common whitefish (Coregonus lavaretus) from Lake Ladoga, goldfish (Carrasius auratus), and crayfish (Astacus leptodactylus). If the Sevan trout is likely to become extinct in its "home" lake, it seems that it will survive in Issyk-Kul Lake (Kyrgyzstan) where it was introduced in the 1970s.

Due to anthropogenic impact, changes have occurred in all the biological components of the lake, including bacteria, benthos, and of course fish. Thus, the benthic mass increased 10-fold in 1940, due to oligochetes and chrinomices. Today, the former prevail and multiply the oxygen-rich residue at the bottom of the lake.

The bojak and winter bakhtak species of the Sevan-endemic trout have already disappeared. The summer bakhtak occurs rarely; the gegharkuni is still capable of reproducing naturally. In 1980s, the quantity of Sevan koghak significantly decreased. Numerous reasons for this have been identified:

• The level of the water was lowered, the patches of rivers changed, and the trout (gegharkuni and Aestivalis species) lost their natural spаwning places. Changes in the areas near the shore (mossing, disappearance of macrophyte plants) also had a negative impact on the trout lays. The trout spawn only in certain areas, with oxygen-rich underground water at the depth of 25–30 m.
• Deoxidization of the bottom is extremely detrimental for salmon, which are used to more than 4 mg O₂ per litre.
• In the last 10 years, poaching rapidly increased, which significantly reduced the number of fish in the lake.

Other species

The lake is an important breeding ground for the Armenian gull (Larus armenicus) with about 4,000–5,000 pairs. Other birds which visit the lake include Bewick's swan (Cygnus columbianus), lesser white-fronted goose (Anser erythropus), red-crested pochard (Netta rufina), ferruginous duck (Aythya nyroca), and great black-headed gull (Larus ichthyaetus). The mouflon are suffering a great population decline due to poaching and habitat loss. The Sevan trout, which made up 30% of the fish in Lake Sevan, have virtually disappeared. Another endangered visitor to the lake is the Armenian leopard or panther (Panthera pardus tullianus).

References

Bibliography