Re-understanding of the source of the Three Rivers.

The source of the Yangtze River is the region with the most remarkable biodiversity characteristics at high altitude in the world, and it is known as the natural germplasm resource pool of alpine organisms. Sanjiangyuan region has a unique and typical alpine ecosystem, which is a typical representative of the alpine environment in Central Asia Plateau and the alpine grassland in the world. Vegetation types include coniferous forest, broad-leaved forest, mixed coniferous and broad-leaved forest, shrub, meadow, grassland, swamp and aquatic vegetation, cushion vegetation and sparse vegetation, which can be divided into 14 formations and 50 formations. There are three kinds of national second-class protected plants, namely Picea crassifolia, Meconopsis rubra and Cordyceps sinensis, and 3 1 species of Orchidaceae listed in Appendix II of the International Trade Convention. There are 34 species of provincial key protected plants in Qinghai Province. There are 85 species of wild animals, 237 species of birds (including 263 subspecies) and 48 species of amphibians and reptiles. There are 69 species of national key protected animals, including Tibetan antelope, wild yak, snow leopard 16, and 35 species of blue sheep and Tibetan gazelle. In addition, there are 32 provincial protected animals, such as Ai Hu, sand fox, striped goose and red duck.

[Edit this paragraph] Geographical location

Rivers, lakes and swamps are densely covered in the source area of the Three Rivers, and snow-capped mountains and glaciers are widely distributed. It is the region with the highest altitude, the largest area and the richest wetland types in the world, and is known as "Heyuan", "China Water Tower" and "Asia Water Tower". The regional division is: the source area of the Yellow River is 6.5438+0.67 million km2, accounting for 46% of the total area of the source area of the Three Rivers; The source area of the Yangtze River is 6.5438+0.59 million km2, accounting for 44%. The source area of Lancang River is 37,000 square kilometers, accounting for 10%. 25% of the total water volume of the Yangtze River, 49% of the total water volume of the Yellow River and 15% of the total water volume of the Lancang River all come from the source area of the Three Rivers.

Sanjiangyuan region is the hinterland and main body of the Qinghai-Tibet Plateau, with mountainous landform, long mountains, high terrain and complex terrain, with an altitude of 3335 ~ 6564 meters. The climate in the region belongs to the Qinghai-Tibet Plateau climate system, which is a typical plateau continental climate. It is characterized by alternating hot and cold seasons, distinct wet and dry seasons, small annual temperature difference, large daily humidity difference, long sunshine time, strong radiation and no distinction between four seasons.

[Edit this paragraph] Environmental protection

Historically, the source of Sanjiangyuan was once a plateau meadow, with abundant water plants, scattered lakes and rich wildlife population, and was called the "pure land" of ecology and life. But the reality is not optimistic and worrying. In recent decades, due to many natural and human factors such as natural and man-made disasters, the ecological environment of the entire Qinghai-Tibet Plateau has obviously deteriorated, and the situation has become increasingly severe. At present, with global warming, the glaciers and snow-capped mountains located in the hinterland of the plateau are shrinking year by year, and many rivers, lakes and wetlands are shrinking and drying up. The area of desertification and soil erosion is still expanding; Desertification and grassland degradation are increasingly prominent; Long-term deforestation has seriously damaged a large area of grassland and nearly half of the forest; Pests and rats are rampant; Rare wildlife poaching is serious; Disorderly gold mining and cordyceps sinensis mining have been repeatedly prohibited; Threatened biological species account for more than 20% of the total species, far higher than the world average 10%- 15%. In some areas, human beings have been unable to survive and have been forced to migrate.