Yenisei L.
The largest river in Russia. Located in northern Asia, on the west side of the Central Siberian Plateau. It is formed by the confluence of the Yenisei River and the Yenisei River. It originates from the Dongsayan Mountains and the Tangnuoula Mountains, and meanders northward into Yenisei Bay in the Kara Sea of the Arctic Ocean. The length below the junction is 3487 kilometers, and it is 4092 kilometers away from the source of the Little Yenisei River. The basin covers an area of 2.58 million square kilometers. The main tributaries are Angara River, Shiquan Tunguska River, Lower Tunguska River and Kuleyika River.
Above the exit of Mincinsk concave, it is upstream, with a length of 474 kilometers. The area from Heyuan to Kemchik estuary is a wide grassland basin with a riverbed width of 200 ~ 400 meters. Below the Kemchik estuary, the river turns sharply north and goes deep into the Xisayan Mountains. The deep water in the valley is urgent, there are many dangerous beaches and many people fall into the water. It is 876 kilometers long from the exit of Minsusinsk concave to the middle reaches of angara estuary. After the Abakan River was flooded, the water volume increased greatly, the valley was widened to 5 kilometers and the riverbed was more than 500 meters wide. Then it enters Krasnoyarsk Reservoir, with a total length of 386 kilometers, passing through the northwest branch of East Sayanling. Below Krasnoyarsk, the valley widens again, but there are many rivers and hills in the valley, with rapid water flow and large drop. From the confluence of Angara River to the downstream of the estuary, the length is 2 137 km. Several tributaries were accepted one after another, the water volume soared, the river bed widened and the valley expanded. Below the Lower Tunguska River, the current is slow and stable, and sand island beaches, swamps and wetlands appear in the valley. There are many tributaries and islands in the delta, and the width of the estuary is 80 kilometers. The average annual discharge of the estuary is 1.98 million cubic meters per second, and the annual runoff is 624 cubic kilometers. Due to the asymmetry of the water system, the water volume of the east bank tributary is 5 ~ 6 times that of the west bank tributary. The ratio of seasonal runoff to annual runoff is 6% in winter (12 ~ February of the following year), 5 1% in spring (March ~ June), 22% in summer (July ~ August) and 9 ~165438+/kloc-in autumn. River water supply mainly comes from melting ice and snow, followed by summer and autumn rainfall. The flood volume is large and long in spring, small and short in summer, flooding in spring and summer, and the flood season lasts for 2 ~ 3 months. The headwaters and tributaries of the angara River flow out of Lake Baikal, which can regulate the main stream. The maximum flood-dry flow ratio (estuary) is 53∶ 1. In the winter dry season, the flow rate is 2500 cubic meters per second. Due to the large span of the river, the difference between freezing period and thawing period is great, and there are many floating ice in spring, which blocks the river and causes the water level in the middle reaches to skyrocket. There are many ice flows in autumn, and ice blocks are formed in some areas, which is easy to cause floods. June 10 ~ 1 1 The whole river was frozen, which lasted for 6 ~ 8 months, with the upstream thawing in April and the downstream thawing in June. The sailing period is about 3 ~ 5 months.
Water resources are abundant. Large Krasnoyarsk Hydropower Station and Sayan-Shushensk Hydropower Station have been built on the main stream. The river is also an important waterway trunk line in the nearby area. Seagoing ships can be traced back to Igalka, and there are regular voyages under Sayan Nogol. The basin is rich in forest, coal, iron, copper, nonferrous metals and aquatic products. The downstream fishery is developed. The scenery on both sides of the strait is beautiful and magnificent, and the summer tourist routes can reach Dixon. The main river ports are Abakan, Yenisesk, Igalka and Dujinka.