Lake Sevan

Lake Sevan is the largest body of water in both Armenia and the Caucasus region. It is one of the largest freshwater high-altitude lakes in Eurasia. The lake is situated in Gegharkunik Province, at an altitude of above sea level. The total surface area of its basin is about, which makes up of Armenia's territory. The lake itself is, and the volume is. 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 has significant economic, cultural, and recreational value. Its sole major island is home to a medieval monastery. The lake provides some 90% of the fish and 80% of the crayfish catch of Armenia.
Sevan was heavily exploited for irrigation of the Ararat plain and hydroelectric power generation during the Soviet period. Consequently, its water level decreased by around and its volume reduced by more than 40%. Later, two tunnels were 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 at an altitude of above sea level, deep, covered an area of , and had a volume of.

Etymology

In the Middle Ages, Sevan was solely the name of the island and the monastery built on it. In the 19th and early 20th centuries, Russian and European sources sometimes referred to the lake as Sevanga or Sevang, Per folk etymology, Sevan is either a combination of sev and vank’, sev + Van, or originates from the phrase sa ē vank'ə.
The scholarly explanation, first suggested by in 1896, is that Sevan originated from the Urartian word suinia, usually translated as "lake". It is attested on an 8th-century BC cuneiform inscription by the Urartian king Rusa I, found in Odzaberd, on the southern shore of the lake.
The historical Armenian name of the lake, attested in early medieval texts, is Sea of Gegham. The historic Georgian name of the lake is Gelakuni, which is essentially the Georgian transcription of Armenian Gegharkuni. In classical antiquity, the lake was known as Lychnitis. John Chardin, who visited the lake in 1673, called it the "Lake of Erivan" and wrote that it was called Deria-Shirin by Persians and Kiagar-couni-sou by Armenians.
The Turkic name Gokcha or Gökche, which means "blue lake" was also used in Russian and British sources from the 17th to early 20th centuries.

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 its environmental, economical, social, scientific, cultural, aesthetic, medical, climatic, recreational, and spiritual value."
Chardin in 1673 noted the "extraordinary sweetness of the water", the "small Island in the middle of it; where stands a Monastery built about 600 years ago, of which the Prior is an Archbishop", and "nine sorts of fish which are there taken; the fairest trouts and carps which are eaten at Erivan being caught in this Lake".
Naturalist and traveler Friedrich Parrot, best known for ascending Mount Ararat in 1829 for the first time in history, wrote:

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 tectonic formation created a Palaeo-Sevan, ten times larger than the present lake. 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 altitude 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 booklet, Armenian engineer Sukias Manasserian proposed using Sevan's water for irrigation and hydroelectric power generation. He proposed draining the lake by. Major Sevan would completely dry out, while Minor Sevan would have a surface area of.

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 through excavation. A tunnel was bored around 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 per year. The water was used for irrigation and the Sevan–Hrazdan Cascade of six hydroelectric power stations on Hrazdan River.

Indices	1936	2000	Decrease
Height above sea level, m	1915.97	1896.65	-19.32
Lake surface, km²	1416.2	1238.8	12.5%
Mean depth, m	41.3	26.8	35%
Maximum depth, m	98.7	79.7	19%
Water amount, km³	58.48	33.20	43.2%

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 by 2002, while the volume decreased by 43.8%. 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

Arpa–Sevan tunnel

By the time of the Khrushchev Thaw, "it had become evident that the ecological and economic consequences of extensive exploitation of the water of Lake Sevan were too undesirable to continue in the same way." Soviet Armenian leaders soon agreed that "the best way to solve the issue would be to construct a canal to divert water from Armenia's Arpa River into the lake." To support this project, Yerevan needed assistance from the all-union budget. On Victory Day 1961, Armenian officials, led by First Secretary Yakov Zarobyan, together with Marshal Ivan Bagramyan, met with Nikita Khrushchev at the lake to discuss the Arpa-Sevan proposal. Guided by advice from Khrushchev's close ally Anastas Mikoyan, the Armenian leadership managed to persuade Khrushchev to support the project, "estimated to be 480 million rubles."
The plan for the Arpa-Sevan tunnel was approved on 12 August 1961 by the Council of Ministers of the Soviet Union. It envisioned diverting water from a reservoir of the Arpa River near Kechut through a long tunnel to the lake near Artsvanist. Armenian authorities "moved to begin the implementation of the project" on 29 August 1961. The tunnel was eventually completed in 1981 and continues to bring up to of water to Sevan per year. However, it is estimated that due to climate change, the outflow of the Arpa river will decrease by 22% by 2030.

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 long tunnel was begun from the Spandarian Reservoir on the Vorotan River 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 brings an additional 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 had risen by in the previous six years. It reached in October 2010. The government committee on Sevan forecasts that the level will reach by 2029.
Water level stood at 1900.44 m in November 2019.

Population

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, Sevan, Martuni, Vardenis, Vardenik, Yeranos, Chambarak, Lchashen, Tsovagyugh.

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 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.