Landform of Lena River Basin

The Lena River is mainly divided into three sections, each of which is about 65,438+0,450 kilometers (900 miles): from the source to its tributaries, the Vitim River is the upstream, from the Vitim River to the Aldan Estuary as the middle, and from the Aldan Estuary to the Laptev Sea as the downstream. In the eastern part of the basin are Zhugejul Mountains, Vilho Yansk Mountains, Olugan Mountains and Harolah Mountains, which form the watershed between Lena River and Yana River, Indigilka River and other small rivers flowing into the Sea of Okhotsk. In the south of the basin, the watershed with Lake Baikal and Heilongjiang (amur river) Basin is Mount Baikal, Mount Ya Blauf and Mount Stanov. The watershed between the western part of the basin and the tributaries on the right bank of Oleniuk River, Hatanga River and Yenisei River is Chekanov Mountain Range, Vilyu Mountain Range and Central Siberian Plateau.

The area of Lena River basin is very asymmetrical. In the upstream part above the confluence of Olyokema River, the basin area of the right bank tributary accounts for about 70% of the whole basin area. The upper reaches of the Lena River flow through mountains and plateaus, with deep valleys and steep banks, which are 300 meters (65,438+0,000 feet) above the river surface. These steep slopes are formed by the North Baikal Mountain on the right bank. The width of the valley is between1.6 and 9.6 kilometers (1 ~ 6 miles), but it can be as narrow as 2 13 meters (700 feet) in some deep valleys, with many rapids and rocky beaches, which have obvious characteristics of mountain rivers.

The Lena River becomes wide and deep in the middle reaches. Especially after the confluence with Mahe River in aulick, the water supply increased and the river width reached 1.6 km (1 mile). From the mouth of Vidim River to the Olyokoma River, Lena River flows along the edge of Badong Plateau on the right bank, forming a huge bend; In some places, the width of the valley has increased to 32 kilometers (20 miles). The valley slope is gentle, the forest is dyed green, and the well-defined platforms formed by rivers are distributed along the valley slope. In this valley, there is a vast flood plain with some small lakes scattered on it.

Below the Oreokma River, the characteristics of the valley will suddenly change. During the journey from Minsk, aulick to Pokrovtsk (97 km (60 miles) upstream of Yakutsk), the Lena River runs along the bottom of a narrow valley with steep slopes. Huge limestone layers are sometimes like castle ruins, or columns, or the shapes of people and animals; This area is a favorite place for tourists and climbers. Several of the largest tributaries of the Lena River meet here. In addition to the Vidim River and Ardan River, there are the Grand Badong River and Olyorkma River injected from the right bank, and the Niuya River injected from the left bank.

. Below the Aldan estuary, the Lena River basin is 19 ~ 26 km (12 ~ 16 miles) wide, and the floodplain is 6 ~ 14 km (4 ~ 9 miles) wide. Here the Lena River flows into the Yakutia lowlands. The river presents a huge arc, extends eastward around the Vikoyansk Mountains to the northwest, and then turns to the north. Flooding plains are all over lakes, usually swamps and riverbeds, forming many islands and tributaries. It is 15 ~ 2 1 m (50 ~ 70 feet) deep, but there are also many shallow rivers with sandbars. In the last section of the river-between the island of Zhorgongo and the delta-when the Lena River flows through the mountain pass between the two banks, the valley narrows, with a width of about 65,438+0.6 kilometers (65,438+0 miles). The delta is like a rectangular peninsula, extending to Laptev Sea about 12 1 km (75 miles), with a width of about 282 km (175 miles). The Lena River Delta is located in the Pangda River system in the frozen wasteland, which originates near Lake Baikal and is divided into 150 waterways in the Russian permafrost zone. The delta is 400 kilometers wide and is a wetland. Part of the delta has been listed as a protected area, known as the Lena River Delta Wildlife Reserve. Mammoth ivory unearthed in delta.

Lena River, together with ob river and Yenisei River, is a magnificent long river, flowing northward in the middle of Xibaili. The Lena River originates from the mountainous area in the north of Lake Baikal, and flows through 4393 kilometers into the Laptev Sea and the Arctic Ocean. The Lena River is the dividing line between two different regions. The west is the Central Siberian Plateau, which is a dense and continuous Tegarin distribution area. It is a wilderness composed of spruce and pine trees, most of which are larch. In the east, there are the majestic Mount Shangyangsk, Mount Suntar Hayat and Mount Cerschi, where the cedar forest and pine forest are difficult to cross, and the winter there is the coldest place on earth except Antarctica.

Downstream from the source of the Lena River, you can reach an 80-kilometer-long area known as the "Column of the Lena River" by taking a two-hour water speedboat. These vertical limestone cliffs cut off vast forests. The rock pillar is 183 meters high and eroded into a charming shape, similar to the steeple of a medieval church. Further downstream is the Charlene hydropower station, which relies on the huge hydropower of the river to generate electricity.

The Lena River Delta has a vast geographical area, second only to the Mississippi River Delta in the United States. Covering an area of 38,073 square kilometers, the huge water system is divided into 150 waterways. Although it is the largest delta water system in permafrost region, a large amount of sediment is regularly washed down downstream and deposited in the delta region, which means that the delta is constantly changing. In this remote northern area, the Lena River is frozen for six to eight months in a year, so it can't be widely used for trade and transportation. But every May and June, the meltwater in the upper reaches makes the river surge, forming paciiythlia in Russian. Its literal interpretation is muddy season, which means completely impassable.

From 65438 to 0985, the vast area of Lena River Delta was designated as Uski Nature Reserve. At that time, the Soviet government set up this area of 14323 square kilometers to protect 29 species of mammals, 95 species of birds and 723 species of plants. On this numerous list, there are bears, wolves, reindeer, minks, Siberian chickens and minks. It is also a breeding ground for birds such as swans and gulls.

The coniferous forest belt around Lena River is very cold in winter, which means that mammals and birds living here all the year round need special adaptability to cope with sub-zero temperatures. Birds such as Arctic goldfinches and Siberian tits have very thick feathers. When the weather becomes very cold, they will curl up into a ball to protect their energy. Mammals such as red fox, gray wolf, weasel, mink, mink and sable all have very soft and thick fur. Sables have very fine fur, and these animals are often unfortunately hunted for their fur. Other animals, such as wolf pounds, have learned to live in places where they can keep warm air under snow. They can continue to eat small plants and insects that can grow in winter months all winter.