青藏高原是中國三大河流的發源地, 但因為水土流失, 湖泊的水存量減少, 氣溫上升又導致冰川的面積減少, 連中東油石大火所造成的污染都隨著雪與雨飄到這世界屋脊...
From 1995 to 2000, the grassland in the area decreased by 2.8 percent, said the scientists.
Another finding by the scientists indicates that in the past 15years, the speed of degradation of the grassland has reached 0.725percent a year, or more than 1,500 square kilometers of grassland reduced to bare land.
There are more than 1,000 lakes on the plateau bigger than one square kilometer with a total area is 44,993.3 square kilometers, covering 49.5 percent of China's total lake areas. Water reserves in the lakes on the plateau are about 608 billion cubic meters, 70percent of the country's total lake water reserves.
Ten of China's 27 biggest lakes, each covering an area of more than 500 square kilometers, dot the plateau. "Most lakes are as high as 4,000 to 5,000 meters and they are generally deep and withsteep banks," said Zhu Liping, a researcher with the Qinghai-TibetPlateau Research Institute.
Statistics show there are 36,793 glaciers on the Chinese part of the Qinghai-Tibet Plateau, covering a total area of 49,873 square kilometers, accounting for 79.5 percent of the total numberof glaciers, 84 percent of the total glacial area and 81.6 percentof the total ice in the country.
Scientists have found the climate of the plateau has been warming and rainfall slightly increased, which could well be an alarming sign of the global warming trend.
According to the data collected by 71 monitoring stations on the plateau, both the temperature and the average monthly rainfallthere have always been climbing from 1961 to 2003.
"From the 1980s on, the plateau has experienced a period in which the temperature has obviously been on the high side," said areport to that effect, noting that the days above zero degree had added two to 3.5 days in the frigid belt and three to 10 days in the temperate belt of the plateau every decade.
"Despite the increased rainfall, the area of glaciers is shrinking," it said, without stating what effects the case will bring about for world climate changes.
Scientists said some global environmental disasters had also contaminated the environment of the plateau.
"From 1990 to 1991, people saw dirty snow falling in the Mount Qomolangma area which scientists determined was polluted by oil smoke floating from the Persian Gulf region," said Gao Dengyi, president of the China Association for Scientific Expedition.
The contents of more than ten chemical elements in the ice and snow samples collected have rocketed five to 15 times from 1975 to1992, he said, with iron multiplying 15 times.
"It was the westerlies that blew the soot of the burning oilfields in the Middle East to the mountain and seriously contaminated both the air and the water environment at its north scope," said Gao. Enditem
全文於Xinhua