Namtso

Namtso

synonym

Namtso generally refers to Namco

Namco, located in the middle of Tibet Autonomous Region, is the second largest lake in Tibet and the third largest saline lake in China. The lake is 4718 meters above sea level and approximately rectangular in shape. It is more than 70 kilometers long from east to west and more than 30 kilometers wide from north to south, covering an area of about 1920 km2.

According to the early scientific investigation, the maximum depth of Namco is 33 meters, but the re measurement of the lake in recent two years found that the maximum depth of Namco is more than 120 meters. With a storage capacity of 76.8 billion cubic meters, it is the highest large lake in the world.

"Namco" is Tibetan, and Mongolian name is "tenggelihai", which means "Tianhu". Namco is one of the "three holy lakes" in Tibet. Namtso is the first sacred lake of the ancient Xiangxiong Buddhism, which is one of the famous Buddhist holy places.

Formation and evolution

The Qinghai Tibet Plateau, where Namco is located, is the product of the compression and uplift of the Eurasian plate and the Indian plate during the orogeny that began about 70 million years ago. According to geological survey data and scientific investigation, Namco area belongs to Lhasa terrane. The basement is composed of Precambrian continental crust at least 1 billion years ago. After a long time, it proliferated to part of Qiangtang terrane in Late Jurassic

.

Namco is a huge lake basin formed by Himalayan depression at the end of tertiary and the beginning of Quaternary. Its formation and development are controlled by geological structure and formed by Himalayan movement depression. It is a faulted tectonic lake with traces of glaciation. Later, due to the gradual drying of the Tibetan Plateau climate, the area of Namco was greatly reduced. There are 8-10 existing ancient lake rock lines, and the highest one is about 80 meters away from the current lake surface.

Basin characteristics

Location

Namco is located on the Qinghai Tibet Plateau, known as the "roof of the world", which belongs to the "Qinghai Tibet Plateau Lake area" of China's five Great Lakes.

Namco lies between 30 ° 30 ′ n to 30 ° 35 ′ N and 90 ° 16 ′ e to 91 ° 03 ′ E. It is located in the southeast of northern Tibet Plateau, the middle of Tibet Autonomous Region, on the northwest border of Lhasa city and between Dangxiong county and bange County on the southeast border of Naqu City, 240 km away from Lhasa. About 60% of the lake surface is in Bangor County in Naqu area, and 40% of the lake surface is in Dangxiong County in Lhasa city. Namco is about 100 kilometers south from Lhasa. To the South and east of Namco are the high Gangdise mountains and the majestic Nyainqentanglha mountains, and to the north is the hilly plateau of northern Tibet with less fluctuation. The whole region forms a closed inner flow region

.

In the south of Namco, there is NIANQINGTANGGULA mountain, which is covered with snow all the year round. In the north and West, there are plateau hills and broad lakeside. Its southeast is the main peak of Nyainqentanglha mountain, which is straight into the sky and snows all the year round. Its north side is nestled in the gentle and continuous plateau hills. The vast grassland is around the lake. Tianhu lake is like a huge mirror inlaid in the grassland of northern Tibet.

Water body

Covering an area of 1940 square kilometers, Namco is the second largest lake in the Qinghai Tibet Plateau with a circumference of 318 kilometers. It is the largest inland lake in Tibet Autonomous Region of China and the highest Lake in the world

. The water is clear and transparent, and the lake is sky blue.

The third largest saline lake in China (it was the third largest saline lake in China before the 1970s, and it has become the second largest saline lake in China since Lop Nur dried up, and the largest is Qinghai Lake. According to the data of Qinghai Tibet Plateau Research Institute of the Chinese Academy of Sciences, which is engaged in the study of Qinghai Tibet plateau lakes, as of June 2014, the area of selinco, Tibet, which was the third largest saline lake in China, had reached 2391km2 , 369km2 more than Namco, replacing Namco as the second largest saline lake in China after Qinghai Lake.

）It is also the highest saltwater lake in the world, with an altitude of 4718 meters, about 1500 meters higher than Qinghai Lake, the largest lake in the world. The deepest part is about 120 meters. There are more than 1500 lakes around it.

terrain

Namco Lake is a tectonic Lake developed in the large fault depression in the north of Nyainqentanglha, which belongs to the inner flow lake. The lake basin is southwest northeast trending, wide in the West and narrow in the East. In the north of Namco Lake, there are plateau hills with an altitude of about 5000-5500 meters, and the terrain is relatively gentle. In the South and east of Namco Lake, there are valleys of Gangdise mountain and Nyainqentanglha mountain with an altitude of about 4000-4300 meters. From south to north, the height of Nyainqentanglha mountain is about 5500-6000 meters, and its main peak is more than 7000 meters, forming a natural barrier However, due to the barrier to the east of Nyainqentanglha mountains, it becomes an inner flow lake.

There are three large islands in Namco Lake, which are rarely disturbed by the outside world, so there are many birds inhabiting there, so they are called bird island. Langduo island in the northwest is the largest island in the lake. It is 2 kilometers long from east to west and has an altitude of 4854 meters.

hydrology

Namco is the highest Lake in the world and the second largest lake in Tibet. The maximum water depth is more than 120 meters. The salinity of the lake water is about 1.7 g / L. the water quality is slightly salty and can not be drunk. It is the third largest salty lake in China after Qinghai Lake and selinco lake.

Namco is a closed lake, with less precipitation and strong sunshine. The only way to get out of the lake is evaporation on the surface of the lake, with an annual evaporation of 2.304 billion cubic meters. There are two ways to get into the lake: the source of the lake water is mainly natural precipitation and alpine ice melting snow supply, one is the melting water of glaciers in the flow field, and the other is the runoff formed by rainfall on the total area of the basin.

According to the calculation, the glacier melt water entering the lake is 124 million cubic meters per year, and the precipitation runoff is 1.334 billion cubic meters per year. According to the annual rainfall of 410 mm, the amount of water directly falling on the lake is 787 million cubic meters per year. The total annual inflow of the above two items is about 2.256 billion cubic meters. According to the above data, the annual water inflow and outflow of Namco are basically balanced, and the water exchange period of the lake is 34.15 years.

climate

Namucuo is a semi humid and semi-arid transitional zone with abundant light, heat and water resources and low air pressure. The air density measured in Dangxiong Bangor is 0.73 kg / m3, the annual total radiation is about 7000 MJ / m2, the annual sunshine hours is about 3000 hours, and the average annual sunshine rate is more than 65%. The rainy season is distinct from June to October every year, and the average annual precipitation is 410 mm, 11 The dry season is from May to May of the next year.

Compared with the data of Dangxiong and Bangor, the average gale days above 8 are 73.8 days in Dangxiong and 85.5 days in Bangor. Gale days are mainly concentrated from December to the next five years. In this period, the gale days in Dangxiong account for 79.4% of the whole year, and Bangor account for 71.7% of the whole year. Gale days often appear in the afternoon and evening, especially on Namco water. The dominant wind direction of Namco is southwest wind

.

Glacial period

Due to the high and cold climate, the lake freezes heavily in winter, and begins to melt in May next year. When it melts, the ice cracks and makes a loud sound, which is also a natural wonder. Every year, the whole lake freezes on the 15th day of the first month of the Tibetan calendar. By the 15th day of the fourth month of the Tibetan calendar, most of the lake freezes away. Namco is located in the northern Tibetan Plateau, the annual ice period is as long as 5 months (the complete freezing time is nearly 3 months). After the lake is completely frozen, the ice surface is more than 2 meters thick. It can be used not only by pedestrians and animals, but also by cars.

river system

Namco has been injected with water from Rosa, daerguzangbu, chahasutai River, etc.

The water of Namucuo lake is supplied by the melting ice and snow of Nyainqentanglha mountain, and there are many streams along the lake.

natural resources

Species resources

plant resources

The lake is surrounded by a vast lakeside plain, growing Artemisia, bryophytes, edelweiss and other herbs. It is a natural pasture and can be grazed all year round. Herdsmen in northern Tibet rush their cattle and sheep here every year before the winter comes to spend the winter.

Animal resources

The lakeside plain surrounds the lake. At the beginning of summer, flocks of wild ducks come to live and breed. Wild animals such as bear, wild yak, wild donkey, rock sheep, fox, roe and marmot often live around the lake. The lake is rich in scaly fish and non scaly fish on the plateau. The lake area also produces Cordyceps, Fritillaria, Saussurea and other valuable medicinal materials.

The wildlife fauna of Namco area belongs to the sub region of Qiangtang plateau in Qinghai Tibet region. There are more than 20 species of mammals in this area. There are 5-7 species of carnivores, ungulates, lagomorphs and rodents. The most common ungulates are Tibetan wild donkey, Tibetan gazelle, rock sheep and argali. The former two are mostly inhabited in basins and valleys, while the latter two are mostly inhabited in mountains. The dominant species of rodents, plateau pika, is abundant, especially in swamp meadow environment, followed by marmot, vole and Tibetan hamster.

There are wolves, foxes, lynx, bunnies, bears and weasels in the alpine steppe. Among them, weasels are the most common and often haunt rat holes. Snow leopard is a kind of carnivore that can adapt to the alpine and cold desert environment most. It still lives near the snow line

Chinese PinYin : Na Mu Cuo