Kolyma(redirected from Kolyma region)
Also found in: Dictionary.
Kolyma(kŏlĭmä`, kōlē`mə, Rus. kəlĭ`mə), river, c.1,500 mi (2,410 km) long, rising in several headstreams in the Kolyma and Cherskogo ranges, Russian Far East. It flows generally N to the Arctic Ocean at Nizhniye Kresty. It is navigable (June–October) for c.1,000 mi (1,610 km). Its upper course crosses the rich Kolyma Gold Fields, which supplied much of the gold for Soviet foreign trade. Gold mining was begun in the 1930s, and both the fields and the surrounding area were developed using the labor of prisoners from Stalin's Gulag. The Kolyma Range (or Gyda Range), E of the Kolyma River, extends NE from Magadan and rises to c.6,000 ft (1,830 m).
a river in Northeastern Siberia, in Magadan Oblast of the RSFSR and the Yakut ASSR. The Kolyma is 2,129 km long, with a basin area of 643,000 sq km. It is formed by the confluence of the Kulu and Aian-Iuriakh rivers, which rise in the Khalkan Range. In its upper reaches, as far as the mouth of the Bakhapcha River, the Kolyma flows through a narrow, deep valley. In places there are rapids, the most significant of which (the Prizhimaiushchii and Dlinnyi) are above the mouth of the Bakhapcha. The Detrin flows into the Kolyma on the right.
In the middle reaches of the Kolyma the valley is broad. The principal tributaries are the Buiunda, Balygychan, Sugoi, and Korkodon on the right and the Seimchan on the left. In its lower course the Kolyma flows across the Kolyma Lowland for 1,150 km. The left bank is low, but the right is mountainous in places. The channel is sinuous and branched. The major tributaries of the Kolyma’s lower reaches are the Popovka, Iasachnaia, Ozhogina, and Sededema on the left and the Berezovka, Omolon, and Aniui on the right. The Kolyma flows into Kolyma Bay of the East Siberian Sea in three major channels: the Kolyma (Kamennaia), which is to the right and is navigable, the Pokhodskaia, and the Chukoch’ia. The delta is 110 km long. Its area is 3,000 sq km.
The Kolyma is fed by snow (47 percent), rain (42 percent), and subterranean waters (11 percent). Flooding occurs from mid-May through September. The level of the river may fluctuate by up to 14 m. At Srednekolymsk (641 km from the mouth) the average water flow is 2,250 cu m per sec, the greatest water flow is 25,100 cu m per sec (June), and the lowest water flow is 23.5 cu m per sec (April). The annual flow at the mouth is 123 cu km (3,900 cu m per sec). The river carries an average of 5.5 million tons of sediment per year. It usually freezes over in the middle of October and more rarely, at the end of September. Before it freezes, the river is covered with drifting ice and slush, as well as ice jams, which last from two days to a month. In the winter there are naledi (bodies of ice formed by layer-by-layer freezing of river or ground waters that flood the surface of the ice). The river thaws in the second half of May and the beginning of June. During the thaw drifting ice and ice jams cover the Kolyma for between two and 18 days.
The Kolyma is navigable for three to 3½ months from the mouth of the Bakhapcha (regular navigation from Ust’-Srednekan). The principal ports are Ust’-Srednekan and Zyrianka and at the mouth, Cherskii, Zelenyi Mys, and Krai Lesov. Above the confluence of the Kolyma with the Debin, the Kolyma Hydro-electric Power Plant is being built on the Kolyma (1973). In the lower reaches fishing is important (vendace, muksun, whitefish, nelma, and omul). There are gold deposits in the Kolyma Basin.
REFERENCESDavydov, L. K. Gidrografiia SSSR, part 2. Leningrad, 1955.
Zalogin, B. S., and N. A. Rodionov. Ust’evye oblasti rek SSSR. Moscow, 1969.
Resursy poverkhnostnykh vod SSSR, vol 19: Severo-Vostok. Leningrad, 1969.
Domanitskii, A. P., R. G. Dubrovina, and A. I. Isaeva. Reki i ozera Sovetskogo Soiuza. Leningrad, 1971.
K. G. TIKHOTSKII
a bay in the East Siberian Sea, which projects into the mainland between Cape Krestovskii and the delta of the Kolyma River. It is 4–9 m deep, with predominantly low-lying shores, and is covered by ice for the larger part of the year. The bottom is silt and sand. Tides are semidiurnal and measure 0.2 m.