Nutrition and regime of the river Lena. Sources and type of feeding of the Lena River

Lena is the largest river in Siberia. It is also not small by the world standards. In the list of the longest rivers of our planet, it occupies the tenth place. The length of Lena is four thousand four hundred kilometers. The catchment basin is located on an area of almost two and a half thousand square kilometers. The majestic river flows through the territory of the Irkutsk region and Yakutia.

Geographical position

The upper reaches of the river, as well as significant areas of basins belonging to its right tributaries, are located in the mountainous regions of Transbaikalia, the Baikal region, and also on the Aldan plateau. In the area of the Central Siberian Plateau lies most of its left-bank basin. The lowest section passes through the Central Yakut lowland.

Division

In the riverbed of the Lena River , three main sections are distinguished. The first one is the upper one. It runs from the source to the place where it flows into the Vitim River. The middle section ends where Lena meets the river. Aldan. On the third, lower section, the river carries its waters to the mouth.

In the upper reaches, Lena's regime is turbulent and fast. In this zone there are all the signs characteristic of mountain rivers. The course of the waters is rapid, and the riverbed is meandering. Many places have rapids. At the same time, the banks are rocky and high. In the upper current, the water stream foams and bubbles, rapidly moving to the north.

The regime of the willful and mighty river changes on the way to Kirensk. Here Lena receives the water of her tributary r. Kirengi and a little calms down. Its channel becomes wider and deeper (in some places this value is equal to ten meters). Rocky banks retreat. Stones are replaced by mighty cedars and tall pine, spruce and fir. Larch grows here too.

The river acquires even more power after it flows into Olekma - its right tributary. Further up to Aldan Lena flows along the Prilensky plateau. Here its banks have peculiar and extremely steep slopes.

The average current comes to an end after Lena meets her right tributary - Aldan. In this place the great river of Siberia forms numerous channels with small islands.

In the lower reaches of the river, Lena spreads in all its breadth. In these places it shows all the power and greatness of the Siberian river, which can not but cause admiration and delight.

Food

Fifty percent of its annual runoff is received by the river from melting of snow cover, and also precipitation in the form of rains. Additional sources of food for the Lena River are groundwater. From them, it receives one to two percent of its runoff. Thus, the type of supply of the Lena River is mixed. But not only the listed sources increase the flow of the majestic Siberian beauty.

The sources of power of the Lena River are also all its tributaries. This list includes Aldan and Chaya, Vitin and Olekma, Kuta and Viluy, Kirenga and Molodo, Chuya and Tuolba, Buotama and Sinyaya. The tributaries have different sizes. The largest of them are the rivers Vitim and Aldan.

The supply of tributaries mainly consists of waters formed as a result of melting of snow, as well as precipitation. Some flow of flow occurs also from the subterranean strata. However, its volume is very small, since in the flowing territory of the river there is a zone of permafrost. The only exceptions are those areas where geothermal sources are located.

Thus, the type of supply of the Lena River and its tributaries is the same. In this case, it refers to the form of mixed.

The food and regime of the Lena River are closely interrelated. However, they depend on the general regime of precipitation. The mouth of the Lena is characterized by extensive spring floods. The river also pours out in the summer. At this time there are several times there are high floods. But the autumn-winter low water in the mouth is low.

The food and regime of the Lena River is drastically changing in the spring. During this period there is a powerful ice drift and melting of snow occurs. During the flood, the water discharge in the estuary zone may be higher than 250,000 cubic meters per second.

Water content

The water regime of the Lena River is characterized by a high flood. In the spring period, the change in the water level mark takes an average of ten to fifteen meters. In the lower reaches this value reaches eighteen meters. The regime of the Lena River in summer depends on the amount of precipitation. At the same time, rain rains are observed several times. A small runoff is typical for the winter.

According to the water content index among Russian rivers, Lena is on the second place. By the volume of its flow, it is second only to the Yenisei.

The Lena River regime is characterized by an average annual discharge in the estuary, equal to seventeen thousand cubic meters for a second. The maximum figure is 200,000, and the minimum figure is 366.

The type of water regime of the Lena River is preserved throughout its extent. However, in spite of this, the water discharge rates have different meanings at different sites. So, above the mouth of the Kirenga River, the average annual water discharge is at 480 cubic meters per second. At the confluence of the Lena River. Vitim has a value of 1700. At the mouths of Olekma, Aldan and Vilyui, respectively, 4500, 6800 and 12100 cubic meters per second. But in the Laptev Sea, where Lena carries her water, the annual runoff is about five hundred and forty cubic kilometers.

Suspensions

Along with the waters of the Lena River, forty one million tons of various dissolved substances fall into the Laptev Sea every year. Suspended deposits are also carried. In the course of the year, about twelve million tons fall into the sea. The turbidity of water is in the range of 50-60 grams per cubic meter. But the mineralization index is 80-100 milligrams per liter.

Ledostav

In the cold periods of the year, the water level is falling, and the regime of the Lena River is drastically changing. During this period, its surface is frozen. The river freely carries its water five to six months during the year in the south and four to five months in the north. In the tributaries of the Lena ice sheet is installed a little earlier. The river itself is frozen for ten days later.

Ledostav in the upper reaches is set at the end of October. In the lower one a month earlier. Opening of the ice can be delayed in the upper course until mid-May, and in the lower one - until the beginning of June.

The regime of the Lena River is radically changed during the spring ice drift. During this period, congestion occurs, which significantly raise the water level.

Thermal mode

The indicators of water temperature along the entire length of the Lena River have significant differences. The monthly averages in the upper and middle reaches are at plus nineteen. But in cold periods (from November to April), the water temperature averages zero.

As for the lower course of the river, here the values of the monthly averages are somewhat lower. In warmer months, they do not exceed seventeen degrees. Significantly longer the period with zero mark. It starts in October and ends in May.

The temperature regime of the Lena River in the upper part of its delta is minimal. In this connection, the most prolonged period of ice cover is observed in this zone.

The spring flood on the Lena River lasts an average of thirty-five days. And in the upper reaches this period is the least prolonged. It is twenty-seven days. In the lower reaches of the river, spring floods can last up to forty-four days.

Ecological problems

The global warming of the climate, which has been observed on our planet in recent years, has a negative impact on the river. In the territory where it flows, over the past forty years there has been a rise in the annual air temperature by four degrees. In this regard, spring floods become much more powerful. This destroys the banks of the river. In addition, the islands move along the river. In 2009, the speed of their descent was fixed, which amounted to twenty-seven meters per year.

Economic use

Lena is one of the cleanest rivers on our planet. In addition, her bed was not changed by man. At Lena, at present, there are not built any dams, hydroelectric power stations, and other water structures. In places far from populated areas, the water is so clean that it can be drunk directly from the river.

As you can see, the unique nature of these places is practically preserved. This is due to the fact that the economic use of the Lena River is not very intensive. This factor is affected by the lack of a large number of settlements, as well as various hydroconstructions. Despite this, Lena serves as the main transport artery located on the territory of Yakutia. It is navigable from the influx of Kachuga to its mouth. The river-bed to Ust-Kut can be used only by vessels with a small draft. The navigation period lasts about one hundred and sixty days in the upper reaches of the river, and in its lower reaches - one hundred and twenty. The main piers are Yakutsk and Zhigansk, Vitim and Lenek, Budun and Kirensk, Kachug and Zhigalovo, Olekminsk and Osetrovo. Some Lena tributaries are also navigable. Among them are Vitim and Olekma, Kirenga and Viluy, as well as Aldan.

In the basin of the Lena River , minerals are mined. Gold-bearing areas and diamond deposits are found on this territory. The Lena basin is rich in rock salt and iron ore, mica and natural gas. Fishing is developed in the lower reaches of the river. Here are found burbot and omul, Siberian vendace and muxun.