Frozen soil has been thawing faster as a result of worsening of the global warming, possibly threatening the Qinghai-Tibet Railway a decade later, according to a Chinese specialist of this field.

Professor Wu Ziwang with the state key lab of frozen soil engineering of the Chinese Academy of Science (CAS) said based on the result from his research into frozen soil in Qinghai-Tibetan Plateau in the past three decades, the frozen soil in the plateau was experiencing signs of shorter freezing days and shrinking of large stretches of frozen soil.

"Fast thawing of frozen soil in the plateau might greatly increase the instability of the ground, causing more grave geological problems in the frozen soil areas where major projects such as highways or railways run through," said Wu.

Wu's observation is proven by a separate report of analysis produced by the Desert Institute of CAS based on temperature monitoring data of the Qinghai-Tibetan Plateau, where frozen soil abounds, over the past 40 years.

The report says temperature in the Qinghai-Tibetan Plateau has been rising notably since 1984 and such a rising tendency will continue due to negative impact of a global warming effect. And by the year of 2050, the average temperature in winter there will go up by one to two degrees Celsius.

Information provided by the Cold and Arid Regions Environmental and Engineering Research Institute of CAS also suggests the area of highly cold swamp and grassy marshland in the Qinghai-Tibetan Plateau has shrunk by 28 percent in the past 15 years.

In areas north to Gandise-Nyainqentanglha Range, where the famous Qinghai-Tibet Railway passes by, the frozen soil has kept thawing faster than expected.

The Qinghai-Tibet Railway, the world's longest plateau railroad, stretches 1,956 kilometers from Qinghai's provincial capital Xining to Lhasa, capital of Tibet Autonomous Region.

Some 960 kilometers of its tracks are located 4,000 meters above sea level and the highest point is 5,072 meters, at least 200 meters higher than the Peruvian railway in the Andes, which was formerly the world's most elevated track.

Track-laying on the railway line was completed last October and the railway line will be put into trial operation on July 1 this year.

In a bid to combat potential dangers as a result of frozen soil shrinkage, builders of the Qinghai-Tibet Railway take measures including building bridges over arid land and constructing a great number of minor projects to protect the ecology and environment along the railway route.

(Xinhua News Agency February 5, 2006)