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a part of the RSFSR. Formed on Sept. 26, 1937. Situated in the south of Eastern Siberia, adjacent to Lake Baikal. Area, 767,900 sq km. Population, 2, 350,000 (1972). Included within the oblast is the Ust’-Ordynskii Buriat National Okrug. Comprising 27 raions, Irkutsk Oblast has 20 cities and 52 urban-type settlements. Its center is the city of Irkutsk. On June 9, 1967, the oblast was awarded the Order of Lenin.
Natural features Irkutsk Oblast occupies the southeastern portion of the Central Siberian Plateau (with an average elevation of 500–700 m), bordered by the Vostochnyi Saian Mountains and the mountain ranges of the Baikal Region (with elevations up to 2,900 m). Located in the oblast’s northeastern part are the Northern Baikal and Patom plateaus, with an average elevation of approximately 1,000 m; individual peaks stand as high as 3,000 m. The Central Siberian Plateau is dissected by deeply entrenched river valleys. The southeastern and northeastern sections of the Oblast are characterized by a high degree of seismicity.
The climate is continental. The average January temperature ranges from— 15°C on the Baikal shores to— 21°C in Irkutsk and— 33°C in Bodaibo. The snow cover lasts 160–170 days a year. The average July temperature is 17°-19°C. Total annual precipitation ranges between 350 and 430 mm; most of it falls during the second half of the summer and the beginning of autumn. On the northwestern and western mountain slopes precipitation is as much as 800 mm. The growing season ranges from 116 to 127 days, with a total accumulated temperature of from 1, 600° to 1, 900°C. Permafrost is widespread, mostly in the north and in the mountainous regions.
The oblast’s river network is part of the basins of the Enisei River (the Angara, Nizhniaia Tunguska) and the Lena River. The principal rivers are the Angara (approximately 1,100 km of which are within the oblast) and the rivers of its basin—the Irkut, Kitoi, Belaia, Oka, Uda (Chuna), Biriusa (Ona), and Ilim. The Lena originates in the Baikal Mountain Range and within the oblast has a length of about 1,500 km; its right-bank tributaries are the Vitim and the Kirenga. The western and southern parts of Lake Baikal are located within the oblast. The large rivers and Lake Baikal are of great economic importance for navigation and fishing, but especially as great sources of water power (the potential hydroelectric power resources amount to 201 billion kW-hr, approximately 10 percent of the RSFSR’s hydroelectric power resources) and water supply.
Taiga soils are widespread over most of the oblast’s territory. Soddy-carbonate, soddy-podzolic, and podzolic-marshy soils predominate in the north; podzolic soils with varying degrees of podzolization in the west; and dark brown and dark gray forest-type, weakly podzolized soils in the southern, forest-steppe region. The Angara Forest-steppe and the Ust’-Ordynskii Buriat National Okrug have extensive chernozems, which are salinized in places. In the mountains there are mountain-forest, mountain-tundra, and bald-mountain-soddy soils. The area covered by forest totals 581,000 sq km (75 percent of the territory of Irkutsk Oblast) and timber reserves, 8.2 billion cu m. Light-coniferous, larch, and pine forests are widespread along with dark-coniferous taiga forests of cedar, spruce, and fir. Steppe and forest-steppe vegetation still remains in some small unplowed areas. There are Japanese stone pine (Pinus pumila) and mountain-tundra vegetation in the high-mountain regions.
There are many valuable fur-bearing animals in the forests (sable, squirrel, Siberian weasel), ungulates (Manchurian red deer, roe deer, elk), and game birds. Acclimatized muskrat are widespread in bodies of water. Lake Baikal and the rivers have valuable species of fish (Arctic cisco, grayling, whitefish, taimen).
Population About 87 percent of Irkutsk Oblast’s population consists of Russians; there are considerable numbers of Ukrainians, Byelorussians, Tatars, and Chuvash. Of the 73,000 Buriats living in Irkutsk Oblast, 48,000 reside in the Ust’-Ordynskii Buriat National Okrug. The Evenki dwell in the north and the Tofalary in the mountains of the Vostochnyi Saian.
The average population density is three persons per sq km. Most heavily populated are the southeastern forest-steppe regions along the railroad. The territories along the Nizhniaia Tunguska and Vitim rivers and along the Vostochnyi Saian are sparsely populated. Urban population amounts to 74 percent. Since the October Revolution, 15 new cities have appeared, including Angarsk, Shelekhov, Svirsk, Zheleznogorsk-Ilimskii, Biriusinsk, and Baikal’sk. The major cities with populations of more than 100,000 are Irkutsk, Angarsk, and Bratsk.
Economy Irkutsk Oblast is developing as one of the most important regions in Siberia for electric power production, power- and heat-consuming enterprises, the lumber industry, the wood-products industry, and the paper and pulp industry as well as for nonferrous metallurgy and the mining of valuable minerals. About 60 percent of the work force is engaged in industry, construction, and transportation. Compared with 1950, the total industrial output in 1970 increased by a factor of 8.3; particularly rapid development has been observed in electric power production and the chemical, petrochemical, and aluminum industries. Approximately 70 percent of the industrial output is produced by the lumber, paper and pulp, wood-products, coal, chemical, and petroleum refining industries as well as by electric power production, the machine-building industry, and nonferrous metallurgy. The light and food industries are represented by furniture, clothing, footwear, knitted goods, leather, meat and dairy, and confectionery enterprises; breweries; distilleries; and fish-canning plants. Most of the industrial enterprises are situated in the southeastern part of the oblast (Irkutsk, Angarsk, Usol’e-Sibirskoe, Cheremkhovo). The industry of Bratsk is also developing rapidly.
Power production in the oblast has developed on the basis of the water resources of the Angara River and the coal of the Irkutsk Basin. The electric power produced by the Bratsk and Irkutsk hydroelectric power plants constitutes about two-thirds of the oblast’s total electric power production. The Ust’-Ilimsk Hydroelectric Power Plant is under construction (1972). About 90 percent of the fuel used is coal. More than 23 million tons of coal a year is mined in the vicinity of the cities of Cheremkhovo and Tulun (the Azei Deposit). On the basis of inexpensive electric power and fuel the following power- and fuel-consuming enterprises have developed greatly: aluminum (Shelekhov, Bratsk); chemical, petrochemical and petroleum refining (Angarsk, Usol’e-Sibirskoe); and pulp (Baikal’sk, Bratsk). An electrochemical combine is under construction (1972) in Zima.
The principal branches of the mining industry are gold (in the vicinity of Bodaibo), mica (in the region of the Mama and Chuia rivers, with processing at Irkutsk and Nizhneudinsk), talc (Onot Mine), iron ore (Korshunovo Ore-dressing Combine), salt (Usol’e-Sibirskoe; a mine at Tyret’ is under construction), marble-type limestones (the Pereval Deposit near Sliudianka), and gypsum (the Zalari Mine).
Machine-building is concentrated in the Irkutsk-Cherem-khovo Industrial Region and is represented by enterprises producing equipment for the mining industry (including dredges for working gold-bearing placer deposits), as well as for the petrochemical and metallurgical industries. Also produced are metal-cutting machine tools, cable products, automobile and tractor parts, receivers, washing machines, and river boats.
The lumber industry is based on the abundant raw material resources of the coniferous forests in the Angara Region. In volume of commercial timber (23 million cu m in 1970), Irkutsk Oblast is the country’s leading producer, whereas in the output of sawn lumber it yields only to Arkhangel’sk Oblast. The logging industry is being moved to the regions of the middle courses of the Angara, Ilim, and Lena rivers. The first unit of the Bratsk Lumber Industry Complex has been put into operation; this entire complex has been designed to process more than 6 million cu m of timber. The Baikal and Bratsk Pulp Plants have begun producing cord pulp. In Usol’e-Sibirskoe the Baikal Plywood and Match Combine is now in operation.
The building-materials industry is represented by the following plants: cement, ceramic, and gypsum (plaster) products (Angarsk); glass (Tulun); precast concrete; and bricks. Enterprises of the light and food industries are concentrated in Irkutsk, Angarsk, Usol’e-Sibirskoe, and Cheremkhovo; outstanding among these are the Irkutsk Tea-Packing Plant, the Usol’e Salt Extraction Plant, the Irkutsk Oil and Fat Combine, and the Khaitinskii Porcelain Plant.
As of 1971 there were 83 kolkozes and 98 sovkhozes in Irkutsk Oblast. Lands suitable for agriculture constitute 3.2 percent of the oblast’s territory. Some 1.7 million hectares (ha) are arable. Hayfields total 300,000 ha and pastures, 400,000 ha. Between 1954 and 1960 some 426,000 ha of virgin and unused lands were plowed up. In comparison with the pre-revolutionary period, the sown area has more than tripled and has reached 1.5 million ha, of which more than 60 percent is occupied by spring grain crops, for the most part, wheat (663,000 ha in 1971), oats, and barley. Sown areas of winter rye total 400 ha. The area under industrial crops totals 2,200 ha. There are 73,000 ha under potatoes and other vegetables. Fodder crops occupy 34 percent of the sown area; corn for silage and annual grasses are the major crops planted. The principal regions for grain production are the forest-steppe regions of the Ust’-Ordynskii Buriat National Okrug and the southeastern part of the oblast (the Tulun-Balagansk Forest Steppe).
Stock-raising provides over one-half of all agricultural income. At the beginning of 1972 the livestock comprised 747,000 head of cattle (of which 36 percent were cows), 481,000 pigs, 419,000 sheep and goats, and 4,400 fowls. More than 60 percent of the sheep and goats are in the Ust’-Ordynskii Buriat National Okrug. Reindeer (6,000) are raised in the Katanga Raion and in the Vostochnyi Saian Mountains. Fur farming is important (fox and mink) as well as hunting (sable, squirrel, and muskrat). Pine nuts and berries are gathered in the taiga region. There is fishing in Lake Baikal and in the Angara and Lena rivers.
As of 1970 railroads totaled 1,881 km. During the postwar years the following new railroads were built: Taishet-Lena (730 km), Irkutsk-Sliudianka (134 km), and the eastern section of the Abakan-Taishet Railroad. Under construction in 1975 was the Khrebtovaia-Ust’-Ilimsk Railroad (about 200 km). Approximately 85 percent of the railroad network within the oblast has been electrified. The Tuimazy-Angarsk pipeline ensures the supply of Bashkir petroleum to the Angarsk Petroleum Refinery. As of 1970 automobile roads totaled 16,000 km, of which 3,700 km were paved. The principal roads are the Moscow Highway, the road from Kultuk to the border of the Mongolian People’s Republic, and the roads from Irkutsk to Kachug, and from Tulun to Bratsk. About 7,500 km of waterways are suitable for navigation; the main ones are the Lena, Vitim, and Angara rivers and Lake Baikal. There is an international airport in Irkutsk.
INTERNAL DIFFERENCES. The Irkutsk-Cheremkhovo region has more than one-half of the oblast’s population and almost two-thirds of the oblast’s industrial output. The principal industrial centers are Irkutsk, Shelekhov, Angarsk, Usol’e-Sibirskoe, and Cheremkhovo. In this region are the Irkutsk Hydroelectric Power Plant and large thermal electric power plants and the machine-building, coal, petrochemical, aluminum, cement, light, and food industries. Suburban farming has become a well-developed trend.
The Ust’-Ordynskii Buriat National Okrug is the oblast’s principal agricultural region. It has one-third of all the output of agriculture and stock-raising. The Tulun-Zima region is the second major region of agriculture. It also has the coal (the Azei Deposit), glass, hydrolysis, and wood-products industries.
The Bratsk-Taishet region, which has developed on the basis of the Bratsk Hydroelectric Power Plant, is the principal region of the lumber, wood-products, and pulp industries (Bratsk, Bi-riusinsk, Nizhneudinsk, Lesogorsk). An aluminum plant is located here as well as the Korshunovo Iron-ore Dressing Combine (Zheleznogorsk-Ilimskii). The Ust’-Ilimsk Hydroelectric Power Plant is under construction (1972).
The Lena-Vitim region is known for the mining of gold and mica, for water transport service along the Lena River (cargo hauls to Yakutia), and for shipbuilding. This region has prospects for developing the lumber and petroleum and gas industries (the Markovo Deposit). There is also commercial hunting.
V. A. KROTOV
Education, cultural affairs, and public health During the 1914—15 academic year Irkutsk Oblast had 954 schools with 58,900 pupils; there were no higher educational institutions. In the 1971–72 academic year there were 475,000 pupils studying at 1,822 general education schools of all types; 49,500 pupils were enrolled in 50 specialized secondary educational institutions; and 56,400 students were studying at seven higher educational institutions (A. A. Zhdanov University, polytechnic, medical, pedagogical, foreign-language, agricultural, and national economics institutes—all in Irkutsk). In 1971 there were 129,300 children in 1,331 preschool institutions. Actively operating are 34 scholarly and scientific institutions, including the Eastern Siberian affiliate of the Siberian Division of the Academy of Sciences of the USSR with eight institutes.
Irkutsk Oblast (as of Jan. 1, 1972) also has 1,047 libraries (with 11, 675,000 books and journals); six theaters (the musical comedy, dramatic, young people’s and puppet theaters in Irkutsk; the Cheremkhovo Dramatic Theater; and the Bratsk Puppet Theater); museums including the regional studies museum in Irkutsk (with its affiliate the home of the Decembrist S. P. Tru-betskoi in Irkutsk), an art museum, a district regional studies museum in the settlement of Ust’-Ordynskii, and a regional studies museum in Bratsk; 1,228 clubs; 60 motion-picture theaters; and 1,845 motion-picture projectors. Extracurricular institutions in the city of Irkutsk include a Palace of Pioneers, a station for young naturalists, and a children’s railroad.
The following oblast newspapers are published: Vostochno-Sibirskaia pravda (since 1917) and the Komsomol newspaper Sovetskaia molodezh’ (since 1924). There is one radio station and one television channel in the oblast. Broadcasts are relayed from Moscow, and the program entitled “Orbit” is received. There are television centers in Irkutsk and Bratsk.
By Jan. 1, 1972, there were 301 hospitals in Irkutsk Oblast and 56 dispensaries. There were 29,400 hospital beds (12.5 beds per 1,000 population) and about 6,000 physicians (one physician per 395 population). The oblast has the health resorts of Usol’e-Sibirskoe and Ust’-Kut in addition to sanatoriums and houses of rest.
REFERENCESAtlas Irkutskoi oblasti. Irkutsk-Moscow, 1962.
Grigor’eva, A. A., V. P. Sotskii, and V. V. Vorob’ev. Irkutskaia oblast’. (Ekonomiko-geograficheskaia kharakteristika). Irkutsk, 1962.
Problemy razvitiia i razmeshcheniia promyshlennosti i transporta Irkutskoi oblasti. Irkutsk, 1965. (Collection of articles.)
Narodnoe khoziastvo Irkutskoi oblasti. Statisticheskii sbornik. Irkutsk, 1967.
Rossiiskaia Federatsiia. Vostochnaia Sibir’. Moscow, 1969. (From the series Sovetskii Soiuz. )
Vostochnaia Sibir’. Moscow, 1963.
Razvitie proizvoditel’nykh sil Irkutskoi oblasti v 1971–1980 gg. Irkutsk, 1971.