|
The Highest Lake-Azure Nam Co
 In the Tibetan language, Nam Co means " the lake in heaven," which lies between the two counties Dumxung and Bangoin to the north of Lhasa, Tibet. To the south of the lake is the grand Nyainqentanglha Mountains; to the north and northwest is the rolling North Tibet Plateau. The lake is narrow and long, with a length of 78.60km from east to west, a maximum width 50km from north to south, an average width 24.9km, and an area 1961.3km2. On the lake bank there distribute 8 sand dykes of the ancient lake, the highest among which is 80.0m higher than that of present lake level . It shows the trace of crustal rising .
Of course Nam Co is not bestowed by "heaven." About 2 million years ago, there happened a violent crustal movement. The Qinghai-Tibetan Plateau rose by a large margin, and the salt bed is extruded. Some folded and rose, forming the high mountains; some sank and fell, forming the valley or the basin among mountains. Nam Co was formed on the basis of the crustal subsiding as well as the influence of the glacier activity. The area of earlier Nam Co was extremely vast, and its elevation was much lower than present . The climate at that time was quite warm and moist, and the lucid, blue, and boundless lake water was just like a sea. Later on, due to the constant rise-up of the crust, Nam Co ascended accordingly. Also, since 10,000 years ago, the plateau climate became drier, the water sources reduced, the lake area shrank greatly, and finally the lake rose to the present height. The present elevation of the lake surface is 4718 meters, highest in the world among the lakes with an area over 1000 square kilometres. The elevation of Orba Co on Qinghai-Tibetan Plateau reaches 5465 meters, but its area is very small. Lake Titicaca -a famous high-mountain lake in the Andes Mountains of South America covers an area up to 8330 square kilometers, but its elevation only reaches 3812 meters, nearly 1000 meters lower than Nam Co .
The lake water of Nam Co is mainly replenished by the melted ice and snow on the high mountains and natural precipitation. The lake water can not flow outward, and it is the largest land-locked lake in Tibet. The precipitation in the lake region is scarce, the sunshine is fierce, and the evaporation is huge. The lake water is bitter and salty, and can not be drunk. It is the second largest salt water lake in China, only smaller than Qinghai Lake. The pH of the lake water is 7.8-9.5, and the mineralization degree is 0.173-1.732 g/L.
Nam Co has another name, Tenggeli Sea or Tenggeli Lake, which means "Lake in heaven," because the lake water is as azure, bright and clean as the cloudless blue sky. The snow peaks around the lake look like solidified silver waves, reflected in the lake, which is solemn but extremely natural. In the lake there are 5 islands, and on the southeast is the Zhaxiduo Peninsula make up of limestone. On the peninsula, there developed the karst topography, including stone pillar, natural bridge, and limestone cave, which compose beautiful and colorful scenery.
Owing to the extremely cold climate, the lake surface freezes up thickly in winter. By the next May, it began to melt, when you can hear the loud sound of ice split, spreading several miles away, which is also a natural wonder.
Nam Co is abundant in resources, especially minerals, such as salt, alkali, Glauber's salt, and boron. Also, the lake teems with fish, fish with thin scale or no scale swim in groups in the lake, which are mainly Schizothorax and Nemacheolus. These fish differ radically from the same kind of fish in the plain, and are developed from local fishes of 2 million years ago, which gradually are adapted gradually to the special environment of the plateau with the crustal uplift. Some fishes are still retaining the primitive characteristic of big head and short tail. Schizothorax can generally grow to be 1-2 kg , and the big ones can reach 7-8kg , even dozens of kg's. Because the Tibetan people did not have the habit of eating fish in the past, the fish swims over to people one after another when they are nearing the lake bank, never frightened. Each summer, shoals of fish in the lake swim over to the lakeside. When laying eggs at the river mouth and/or beaches, they can be easily caught.
 The rivers flowing into Nam Co are Luosa, Da'erguzangbo, and Chahasutai. Around the lake is a vast and boundless lakeside plain, where grows herbs, such as wormwood, moss, edelweiss, and is a natural pasture with plenty of water and grass. It is fit for herding all the year around. The herdsmen of the North-Tibet drive cattle and sheep here to live through the cold snowy winter before the winter comes each year. Nam Co in the summer is the most rejoicing and exciting time in a year: wild animals like wild yak, wild sheep, and hare are eating grass at the wide grassland;  countless migratory birds fly here from the South, laying eggs, hatching, and feeding the later generation on the lakeside; shoals of fish in the lake sometimes jump out of the water surface and their silver scales glimmer in the sunshine; the herdsmen raise whips and spur the horses up, the cattle and sheep move about like the clouds flowing in the sky, and melodious, loud and sonorous songs echo in the mountain valleys. The peaceful and tranquil Nam Co is full of vigor and interest. It's no wonder that the Tibetan people regard Nam Co as the symbol of goodliness and happiness. It is really a generous gift granted by the nature.
The Largest Freshwater Lake--Vast Poyang Lake <<
The Lowest Lake-Moonlight Aydingkol Lake >>
|