Hrazdan (river)

Names

The river is called Ildaruni in Urartian inscriptions.

The name Hrazdan derives from a Middle Iranian form of Avestan Frazdānu, which in Zoroastrian mythology is the body of water by which Vishtaspa converted to Zoroastrianism. Frazdānu is composed of the elements fraz 'elevated, high' and dānu 'river'. Dānu derives from the same Iranian root as a number of hydronyms in Europe, such as Don, Dnieper, Danube and Dniester. The change of word-initial fr- to hr- can be seen in a number of Iranian borrowings into Armenian. The Hrazdan is mentioned in Movses Khorenatsi's history. In the history attributed to Sebeos, the form Hurazdan is used, while some later Armenian historians use the form Hurastan.

Its name in Turkic languages is Zangu, Zanga, Zangi, or Zengy. It was called Zanga in Tsarist Russian nomenclature.

Geography

Lake Sevan (with 30 rivers contributing to its storage), the largest located in the central part of the country and the Hrazdan River which originates from it, together form the "Sevan-Hrazdan Management Area", which is one of the five sub-basins of the 14 sub-basins of Kura and Araks basins of Armenia. The river originates from the lake at an elevation of 1900 m.

The river drains a total catchment area of 2566 km2. Precipitation volume is 1572 million cubic metre from an annual rainfall of 257 mm with a maximum of 43 mm in May and a minimum of 8 mm during August. The average temperature recorded in the basin varies from -3 C in January to 26 C in July with diurnal variation with the lowest night temperature of -15 C in January and highest day temperature of 44 C in July. The total flow in the river is 733 million cubic meter. The regulated outflow into the river, which forms the Ararat Valley, is utilized for irrigation and hydro-power benefits.

File:Davtashen panorama.jpg|A panorama of the Hrazdan River gorge and Davtashen from Arabkir, Yerevan

Fauna

The fauna reported from the river includes 33 species of chironomids and 23 species of blackflies. The chironomids belong to five subfamilies of Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae, and Chironominae. 25 species of invertebrates comprising two species of rotifers, 13 species of cladocerans and 10 species of copepods have been recorded in the river.

While the fish species contained in the lake consist of the Sevan trout (Salmo ischchan) or "Prince Fish," siga, crucian, carp, crayfish, bojak (Salmo ischchan danilewskii) and winter bakhtak (Salmo ischchan ischchan) and summer bakhtak (Salmo ischchan aestivalis), the river is reported to have species of crayfish as well as karas in abundance.

Development

Main article: Sevan–Hrazdan Cascade

The lake waters have been used for irrigation since the 19th century, and from early 20th century hydro-power development has also been implemented. The lake waters were planned to be used through the river for irrigating 100000 ha in the Ararat Valley out of which an irrigation of 80000 ha was created. The hydro-power development was planned on the river as the Sevan–Hrazdan Cascade involving seven schemes in a 70 km stretch of the river with a total installed capacity of 560 MW with mean annual energy generation of around 500 million kilowatt hours; it is the largest hydro-power generating scheme in Armenia.

The civil works involved construction of diversion works, open canals or tunnels and power house which over the years were in need of substantial rehabilitation as they were all built around the middle of the twentieth century. The works were carried out under a US$25 million loan from the Asian Development Bank.

River pollution

The river water is polluted by effluent flows from agricultural, commercial, industrial, and residential development, but particularly by the untreated wastewater from Yerevan. This affects the water quality in the river with dissolved oxygen (DO) levels (less than 5% of the saturated dissolved oxygen level) remaining much lower than the permissible limits. A study carried out in 2008 indicates that a 16 km stretch of the river, from 2 km upstream of the Yerevan wastewater outfalls to 14 km below, is insufficiently aerated to provide a healthy environment for aquatic life.

References

Bibliography

References

1. "Armenia". Encyclopædia Britannica.
2. "Monitoring Dissolved Oxygen in the Hrazdan River". Acopian Centre for Environment.
3. "Armenia:Water resources". [[FAO]] Organization.
4. (1992). "The Geography of Ananias of Širak: Ašxarhacʻoycʻ, the Long and the Short Recensions". Reichert.
5. (2018). "The Art of Armenia: An Introduction". Oxford University Press.
6. Lang, David Marshall. (1970). "Armenia: Cradle of Civilization". [[Allen & Unwin]].
7. (2002). "Armenian Tsopk/Kharpert". Mazda Publishers.
8. Nalbandian, G. M.. (1983). "К этимологии армянского հրաժեշտ (= hražešt = прощание) и гидронима Հրազդան (= hrazdan = раздан)". Banber Erevani Hamalsarani.
9. Russell, James R.. (1982). "Zoroastrianism in Armenia". University of London, School of Oriental and African Studies.
10. Hübschmann, Heinrich. (1904). "Die altarmenische Ortsnamen". Verlag von Karl J. Trübner.
11. (1999). "Armenia after the coming of Islam".
12. (15 December 1987). "Ayrarat".
13. (1922). "Reports and Papers on the Work for the Refugees". [[League of Nations]].
14. Kiesling, Brady. (1999). "Aediscovering Armenia: An Archaeological/touristic Gazetteer And Map Set For The Historical Monuments Of Armenia".
15. (1834). "A Dictionary of Geography, ancient and modern, etc". Thomas Tegg & Son.
16. (1843). "A Residence of Eight Years in Persia, Among the Nestorian Christians: With Notices of the Muhammedans". Allen, Morrill & Wardwell.
17. [[:ru:Владислав Иванович Масальский. (1894). "[[Brockhaus and Efron Encyclopedic Dictionary".
18. "Hrazdan Gorge Palaeolithic Project: the Geoarchaeology". University of Winchester.
19. (February 2007). "The fauna of chironomids and blackflies (Diptera: Chironomidae, Simuliidae) and hydrochemical characteristics of the Hrazdan River (Armenia)". Entomological Review.
20. (2012). "Zooplankton changes in the long profile of Hrazdan river, Armenia". Scientific Journal of Chemistry and ecology.
21. "Fishing in Armenia". Fishing Centre.
22. (21 May 2013). "ADB makes loan for Sevan-Hrazdan cascade modernization project". HydroWorld: Hydro News.