The Aldan River
The Aldan River, which is the right tributary of Lena, is located in Eastern Siberia, on the territory of Yakutia. Its total length is 2273 kilometers, and the total area of the basin is 729 thousand square kilometers. The source of the river is on one of the northern slopes of the Stanovoi Range, at an altitude of about 1400 meters above sea level. Then her path goes along the Zvereva ridge, then turns north and northeast, along the Aldan upland, and finally, the river turns west and flows into Lena about 160 kilometers below Yakutsk. Part of this route Aldan (between the tributaries of the tributaries Uchur and Mai) flows through a wide valley, then - along the plain between the mountains. In the lower reaches, not far from the mouth, the river is divided into several separate branches. Aldan is one of the largest Siberian rivers. In some places of the lower part its width reaches 15 kilometers. The average annual water runoff ranges from 5000 to 5200 cubic meters per second. This is slightly less than one-third of the total flow of the Lena. The greatest runoff of water is observed in the summer months, and the smallest in winter, when the river is covered with ice. The average flow velocity for the most part of 1.3 is 1.4 m / s. In the same Aldan flows 275 tributaries, the length of which exceeds 10 kilometers. Most of them are located on the right side. The largest of them - Uchur (has the largest drainage), May, Tyra, Timpton. The most significant left-bank tributaries are the Amga (the largest is 1462 kilometers), Notora. In addition, within the Aldan Basin there are more than 51 thousand lakes. The largest of them, Lake Bolshoy Toka, has an area of water mirror 82.6 sq.km. Usually Aldan freezes at the end of October, and the ice cover is opened by the beginning of May. During floods in May and June, the water level in the river rises from 7 to 10 meters. The main food of the river is due to the melting of snows and rains. According to its chemical composition, the water in the river belongs to the category of hydrocarbonate-calcium, the maximum concentration of salts reaches 0.3 grams per liter.
Most of Aldan is navigable, from its mouth to the settlement of Tommot. Navigation on the river continues from June to October. The main cargoes that are transported by water are ore and ore concentrates, as well as industrial goods and food. In the river basin there are numerous mining enterprises processing ore of various metals. There are quite large gold-bearing deposits, as well as deposits of coal and mica. Aldan is rich in fish resources. Of the valuable breeds, it is worth noting, first of all, sturgeon, nelma, sterlet, as well as taimen and burbot (the latter are found in the upper part of the river). The first known settlements of people appeared in these places about 35-40 thousand years ago. There are also numerous parking lots of a later time - the Iron Age and the Bronze Age. At the beginning of the XVII century, the first Russian explorers and settlers began to penetrate here. It was along the Aldan that they moved to Cupid And further to the east, to the Pacific Ocean. Currently, there is a construction project in the Aldan Basin hydropower cascade, consisting of 9 HPS (South Yakutian cascade). However, the timing of its implementation is still unknown.
Hydrology Power snow and rain. Flood is observed from May to July, when the water level rises by 7-10 m, and the flow reaches 30-48 thousand m3/ Sec. Floods are also observed in August and September. Winter consumption is small (4% per annum), in February-April usually does not exceed 230? 300 m2/ Sec. Ledostav lasts about seven months, freezing begins at the end of October, autopsy - in May. Water in chemical composition is hydrocarbonate-calcium, the maximum content of dissolved salts is up to 0,3 g / l (in winter low-water). Having a length of 2 273 km and an area of the basin 729 thousand km2, Aldan is the largest tributary of the Lena, bringing in it more than 30% of its runoff. Estimates of the average annual water discharge at the mouth in different sources differ among themselves and are usually indicated within 5 000? 5 200 m3/ Sec. For 58 years of observations at the hydrological station "Verkhoyansky transport" at 151 km from the confluence of the river to Lena, the average annual water discharge was 5 245,85 m3/ Sec or in the mouth? 5 494,58 m3/ Sec.
Tributaries The largest tributaries are on the right: Timpton, Uchur, Tyry, May, Allah-Yun, Tompo, Barayy, Tumara; Left - Amga, Notor and Tatta. In total, the river receives 275 tributaries, having a length of more than 10 km. The most abundant of these is the Uchur River with an average flow at the mouth of 1 350 m3 / s. The largest catchment near the tributary of May is 171 000 km2. The longest tributary is the Amga, which flows practically parallel to Aldan from its upper reaches and has a length of 1 462 km. At the same time, Amga has the smallest drainage modulus among all other significant tributaries - the average discharge in the estuary is 178 m3/ Sec, which corresponds to the flow module 2,57 l (sec · km2). In the Aldan basin there are more than 114 thousand watercourses and more than 51 thousand lakes. The largest of the lakes within the catchment of the river is Lake Bolshoy Toko. Economic use Aldan is navigable to the quay Tommot, is an important waterway for the export of products of mining enterprises and the importation of food and industrial goods from Lena. The main piers: Tommot, Ust-May, Khandyga, Eldikan. In the basin of the river there are large deposits of gold, coal and mica. In the Aldan basin, it is planned to build the South Yakutian HPP cascade, and the Verkhnayaalda HPP can be built on the river itself.