The Qinghai-Tibet Railway, the world's highest altitude railway line, had caused little impact on the natural environment according to an evaluation report , the Ministry of Railways said.

In a document issued ahead of the first anniversary of the line's opening, the ministry said the railway had "effectively conserved water and soil" on the Qinghai-Tibet Plateau.

The railway line had caused little to no impact on local vegetation and wildlife.

Experts with the Ministry of Water Sources, sent to the plateau in June, said the railway's water and soil conservancy measures had "effectively protected the ecological system on the Qinghai-Tibet Plateau and sources of the Yellow, Yangtze and Lancang rivers."

Another group of experts with the environmental assessment center under the State Environmental Protection Administration (SEPA) said the railway's 33 specially-built passages for wild animal migration had "positive, obvious functions" on minimizing the railway's effect on wildlife.

Another report said the recovery of vegetation along the railway is also "showing initial effect" and transplanted grass is growing well.

"Passengers using the railway to Lhasa can see a harmonious scene and wandering wild animals, as usual," Wang Yongping, spokesman of the Ministry of Railways, said.

Construction of the railway had initially caused some concern because the plateau's ecological environment is believed to be very fragile.

However the Ministry of Railways was determined to go ahead with the project and took a series of measures to keep the project's impact to a minimum.

In a bid to protect the wildlife the ministry built passages at key points along the route to enable animals such as antelopes to safely cross during times of seasonal migration.

Inspections by SEPA experts and the local reserve bureau showed animals had started to become accustomed to the special passages.

The ministry purchased facilities on trains and at Lhasa and Golmud railway stations, to ensure waste produced by passengers along the route was properly disposed.

So far, more than 70,000 tons of waste and sewage had been "properly" disposed of, the ministry said.

A survey showed almost 97 percent of residents in the Tibet Autonomous Region were satisfied with the railway's environmental protection measures, Xinhua News Agency reported.

There have been no reports of environmental pollution caused by the railway, Xinhua said.

(China Daily July 2, 2007)