Tell me about Tibet.

Xizang Autonomous Region, with an average elevation of more than 4,000 meters, is the main part of the Qinghai-Tibet Plateau and is known as the "roof of the world". The terrain here is complex, which can be roughly divided into three different natural regions: the northern Tibet Plateau is located between Kunlun Mountain and Tanggula Mountain, Gangdise Mountain and Nyainqentanglha Mountain, accounting for two-thirds of the total area of the autonomous region; The Yarlung Zangbo River and its tributaries flow between the Gangdise Mountain and the Himalayas, which is a valley in southern Tibet. East Tibet is an alpine valley area, a series of high mountains and deep valleys that gradually turn from east to west to north and south, and it is a part of the famous Hengduan Mountains. Geomorphology can be basically divided into six types: extremely high mountain, high mountain, Zhongshan, low mountain, hilly and plain, as well as periglacial landform, karst landform, aeolian landform and volcanic landform. The Himalayas, which meanders on the south side of the Qinghai-Tibet Plateau, consists of many parallel mountains that are similar to the east-west trend. Its main part is on the borders of China, India and Nepal, with a total length of 2,400 kilometers and a width of about 200-300 kilometers, with an average elevation of over 6,000 meters. Mount Qomolangma, the highest peak in the world, is 8844.43 meters above sea level and stands on the Sino-Nepalese border in the middle of the Himalayas. Within more than 5,000 square kilometers, there are 4 peaks over 8,000 meters and 38 peaks over 7,000 meters.

Rivers and lakes

There are more than 20 rivers with a drainage area of 1 000 square kilometers and more than 2000 rivers with a drainage area of 1 000 square kilometers in Xizang Autonomous Region. The famous rivers are Jinsha River, Nujiang River, Lancang River and Yarlung Zangbo River. Tibet is also the China province with the largest distribution of international rivers, and the sources of famous Asian rivers such as Ganges, Indus, Yarlung Zangbo, Mekong, salween and Irrawaddy are all here. The water sources of rivers in Tibet are mainly composed of rainwater, snowmelt water and groundwater, with large flow, low sediment concentration and good water quality. The Yarlung Zangbo River, the largest river in Tibet, originates from the Gemayengzong Glacier in Zhongba County, at the northern foot of the Himalayas, and flows into India through Luo Yu, which is called Brahmaputra River. The Yarlung Zangbo River (in China) has a total length of 2,057 kilometers, a drainage area of more than 240,000 square kilometers and an average elevation of about 4,500 meters, making it the highest river in the world. The Yarlung Zangbo River Grand Canyon is 5382 meters deep, which is the deepest canyon on earth. The valley bottom of the Grand Canyon is only 74 meters at its narrowest point and about 200 meters at its widest point, with a total length of 370 kilometers.

There are more than 1500 lakes on the vast Qinghai-Tibet Plateau, among which the area of Namco, Selin Co and Zhaxi Co exceeds 1000 square kilometers. There are 47 lakes with an area exceeding 100 square kilometer. Namco is also the highest lake in the world. The lake area is 24 183 square kilometers, accounting for about one third of the total lake area in China. The Qinghai-Tibet Plateau is not only the largest lake-intensive area in China; It is also the plateau lake area with the highest lake surface, the largest range and the largest number in the world. There are many lakes and saltwater lakes here, but few freshwater lakes. There are 7 lakes/kloc-0 above 5000 meters above sea level, all with an area of over 50 square kilometers.

Climatic characteristics

The air is thin, the air pressure is low and the oxygen content is low.

Strong solar radiation and long sunshine time.

The temperature is low and the daily temperature difference is large.

The whole year is divided into obvious dry season and rainy season.

The climate type is complex and the vertical variation is great.

The complex and diverse topography of the Qinghai-Tibet Plateau forms a unique plateau climate. In addition to the general trend of cold and dry northwest and warm and humid southeast, there are various regional climates and obvious vertical climatic zones. Proverbs such as "ten miles are different from the sky" and "one day has four seasons" embody these characteristics. Compared with most parts of China, Tibet has thin air, abundant sunshine, low temperature and less precipitation. Every cubic meter of air in Tibet Plateau contains only about150-170g of oxygen, which is equivalent to 62% to 65.4% of that in plain areas. Tibet is the place with the largest solar radiation energy in China, which is two times or one third more than the plain area at the same latitude? Sunshine hours are also the high-value center in China, and the annual average sunshine hours in Lhasa reach 302 1 hour. The temperature is low, and the annual temperature difference is small, but the temperature difference between day and night is large. The annual average temperature and the highest monthly average temperature in Lhasa and Shigatse are lower than those in Chongqing, Wuhan and Shanghai at the same latitude 10- 15 degrees Celsius. The annual temperature difference between Lhasa, Qamdo and Shigatse 18-20 degrees Celsius? In places above 5000 meters above sea level in Ali, in August, the daytime temperature is above 10 degrees Celsius, and the nighttime temperature drops below zero degrees Celsius. The seasonal distribution of precipitation in Xizang Autonomous Region is uneven, the boundary between dry season and rainy season is very obvious, and it rains many nights. The annual precipitation gradually decreases from 5000 mm in the southeast lowlands to 50 mm in the northwest. From October of 65438/kloc-0 to April of the following year, the precipitation only accounts for 0% to 20% of the annual 10; The rainfall from May to September is very concentrated, generally accounting for about 90% of the annual precipitation.