a city, the center of Aldan Raion, Yakut ASSR, on the Amur-Yakut highway, 648 km north of the Bol’shoi Never railroad station. It is situated on the Aldan Plateau in the basin of the Aldan River. Population in 1966, 15,000. Aldan is the economic and administrative center of the gold and mica industry of Southern Yakutia. The city is the site of a machine-repair plant, a polytechnical school, and a medical school. Formerly the settlement Nezametnyi, which grew with the discovery of major gold deposits in the 1920’s, Aldan officially became a city in 1939. [1—1183—1]
a river in Yakut ASSR, the largest right-bank tributary of the Lena. The Aldan is 2,273 km long and drains 729,000 sq km. The Aldan Basin is located in a permafrost zone where crystalline bedrock appears near the surface. The river originates on the northern slopes of the Stanovoi Range. The riverbed within the Aldan Plateau is stony and full of sandbars. Between the mouths of the Uchur and the Maya rivers, the Aldan flows down a wide valley that narrows in places. Below that it flows gently through an intermontane plain; there are many lakes in the floodplain. In its lower reaches, the Aldan breaks into many branches. The largest tributaries are the Timpton, Uchur, Maya, and Allakh-Iun’ on the right bank and the Amga on the left. Fed by melting snows and rain, the river has a mean annual flow rate of 5,060 cubic meters per second (m3/sec) at its mouth. One-third of the volume of the Lena River comes from the Aldan. The flooding period is at its peak from May through July, with high floods in August and September; the water level increases by 7 to 10 m and the flow rate at the river’s mouth reaches 30,000 to 48,000 m3/sec. In the winter the Aldan’s flow rate is very small (4 percent of the annual); from February to April it usually does not exceed 230 to 300 m3/sec. Icebound for about seven months of the year, the Aldan begins to freeze in its lower reaches at the end of October and is open for navigation again in May. Its chemical composition is calcium-hydrocarbonate water, the maximum concentration of dissolved salts being 0.3 gm// during the winter low water. The Aldan is well stocked with such fish as sturgeon and sterlet.
The Aldan is navigable as far as the harbor of Tommot. The river is important for shipping out mining products and for shipping in food and manufactured goods from the Lena. The principal ports are Tommot, Ust’-Maya, and Khandyga. The river basin has large deposits of gold, coal, and mica.
A detailed hydrographic exploration of the Aldan was made by the Administration for Internal Waterways for the Lena Basin in 1918–26.