The mouth of the Lena River and the source

The mouth of the Lena River begins 150 km from the coast of the Laptev Sea, after it, bypassing the island of Stolb, is divided into a multitude of ducts (there are more than 150 of them). They fan out over a huge area of 45 500 km ² , forming a classic river delta.

Let's begin the description of the river from the very beginning - from its source. In this case, the characteristics of the parameters will be taken from the officially documented information of the Water Register of the Russian Federation.

The source of the river

A small lake of Nagediene, according to the State Water Register, is the source of the Lena River. It is located 7 km from Lake Baikal, on the western side of the foot of the nameless mountain of the Baikal ridge with a mark of 2023 m. The coordinates of the source are determined by the values: northern latitude 53 degrees 56 minutes, eastern longitude 108 degrees 5 minutes. In administrative terms, this is the territory of the Kachugsky District of the Irkutsk Region. The great Siberian river begins with a small brook, which can go to a five-year-old baby. Here the bed of Lena is subject to freezing and drying. But after the first tributaries flow into it, it acquires a constant flow.

The source and mouth of the river

Lena is located in Eastern Siberia. The river flows through the Irkutsk region and Yakutia, taking tributaries from Transbaikalia, Buryatia, Krasnoyarsk and Khabarovsk krai.

The zero value indicates the height of the river mouth. Lena has a length of 4294 km - this distance is registered in the state register of surface water bodies in Russia. The total drop is 1650 m - the difference in water level marks between the source (1650 m) and the mouth (0 m). The average slope is 0.38 m / km. Theoretically, this means that with each kilometer in the direction of the current of the river, the earth's surface is reduced by an average of 38 cm. Actually, the channel slope and the current velocity in the upper reaches of the river are many times higher than the values of these hydrological characteristics at the mouth of the Lena River. These characteristics depend on the terrain.

Upper

In different geographical conditions are the source and mouth of the river. Lena begins in the mountain system of the Baikal region, then crosses the Patom plateau, goes to Prilenskoe plateau and descends to the Central Yakut lowland. Therefore the watercourse is conditionally divided into 3 approximately equal parts. The first of these is the upper reaches of the Lena, from the beginning to the confluence of the Vitim River. The length is 1580 km. The mark of the Vitim estuary is 176 m, therefore, the average slope of the upper part of the Lena is 0.93 m / km. The river bed in the upper reaches is winding and swollen, flowing in a mountain-bounded valley. When approaching Vitim becomes wide (up to 2 km) and deep (up to 12 m), sometimes the islands are broken into sleeves. The river asymmetric valley with a pronounced floodplain and terraces extends in widths up to 30 km in places. The left bank is sloping - this is the Central Siberian plateau. The right bank is steep and high - the outskirts of the Patom Highlands. Slopes on either side are covered with taiga, sometimes replaced by meadows.

Average Current

This part of the Lena, with a length of 1,415 km, is confined to the mouths of the largest tributaries, beginning with the confluence of Vitim (176 m) and ending with Aldan (elevation 72 m). The average gradient is 0.074 m / km. Lena after Vitim becomes a full-flowing river. After a confluence of 2,089 km from the mouth of the Olekma River, the Lena Valley narrows. The banks are rocky, they are composed of limestone. This Lena Pillars - they are sheer, have a bizarre outlines. In the town of Pokrovsk, Lena breaks out into the plain, the valley extends to 20 km or more, the floodplain covers a strip up to 15 km wide. Slowing down the flow speed - from 1.5 m / s to 0.5 m / s.

Lower Current

From the mouth of the Aldan to the Laptev Sea, the lower Lena extends. The length of this part of the river is 1300 km. With the confluence of powerful tributaries (Aldan and Vilyuya), Lena becomes a giant river. The width of its one-arm channel can be up to 10 km deep, up to 20 m , and up to 25 km, where the island formations are located. The flow of the river is majestic - it slows down due to a slight slope, which is 0.05 m / km or less in the lower part of the river.

The mouth of the Lena River

A photo from space shows the beauty and sweep of the largest river delta of the northern hemisphere. Its area it surpasses the famous mouth of the Nile for 20 thousand km ² . The top of the delta is the island of Stolb, 150 km from the sea coast. The riverbed of Lena is divided into a hundred and a hundred streams. The largest of them are three: Olenek (limits the delta from the west), Bykovskaya (eastern) and Trofimovskaya (middle), which discharges 70% of the annual runoff into the sea. Shipping is carried out along the Bykovskaya channel, which is the seaport of Tiksi.

Since 1986, the mouth of the Lena has acquired the status of the biosphere reserve of Russia - Ust-Lensky. This is a unique habitat of tundra communities, represented by dozens of species of Red Book plants, mammals of 32 species. Here are the massive nesting grounds of water birds returning here annually for the continuation of the family and molting. Ichthyofauna is diverse and rich.

Hydrology

The area of the Lena catchment area is 2.49 million km ² . The annual volume of runoff varies from 490 to 540 km ³ in different years. The average annual discharge at the gauging stations at the mouth of the Lena River ranges from 15.5 to 17.8 thousand m ³ / s.

Feeding the river gives atmospheric precipitation, distributed in volumes approximately equally between snow thawed and rain. Groundwater recharge makes up less than 2%, which is explained by the conditions of permafrost.

For the river is characterized by high spring floods, the passage of several large floods in the summer and autumn-winter low water with a decrease in water discharge in the lower reaches to 370 m ³ / s.

Ice regime of the Lena is distinguished from other rivers by a powerful layer of strong ice, formed in conditions of a long, little snow and cold winter. In the upper reaches, the period without the ice cover of the river lasts up to six months, in the lower reaches - for a month or two less. Ledostav in the upper reaches occurs at the end of October, and in the lower reaches - at the end of September. The ice begins to open from the headwaters to the middle of May, and in June - at the mouth of the Lena River. In meters, the excess of the high water level above the low-water level reaches values from 8 to 18, which causes flooding of low areas and emergency situations in settlements along the river banks.

Unique landscapes

The pristine beauty and richness of nature, both at the source and at the mouth of the Lena River, are impressive. But the shores in the national nature park "Lena Pillars", which is the World Heritage of UNESCO, are especially fabulous. The Lena Pillars begin 180 km from Yakutsk upstream and extend for many kilometers along the right bank and places along the left bank.

Geological and landscape phenomena are sheer calcareous rocks up to 200 m high. The fantastic outlines of the pillars brought to the reverence of the ancient man, modern tourists admire them. Another miracle are the mountains of the purest and lightest waving tusculans. At the mouth of the tributary Deering-Yuryakh, the sites of the primitive man were found. On the territory of the park, fossils of ancient fauna have been discovered: the remains of mammoth, buffalo and rhinoceroses.

Interesting legends can be heard from local residents and the mouth of the Lena River. Underground city with streets and eternal lights, according to local residents, is near the sea coast. You just need to find in it a secret entrance. It is also said that the German submarine pestered the island of Stolb at the top of the delta in the Great Patriotic War.