A top official from Southwest China's Tibet Autonomous Region said the environment along the landmark Qinghai-Tibet Railway has been effectively protected since its opening last July.

Measures have been taken to preserve the ecological environment along the 1,956-km route, the first ever railway to link Tibet with the rest of the country, said Qiangba Puncog, chairman of the regional government.

"The Qinghai-Tibet Railway has been praised by people in Tibet as the 'economy line', 'unity line', 'happy line' and 'eco-line'," he said in a document available before Wednesday's press briefing on Tibet's social and economic development.

According to a recent poll conducted by the State Environmental Protection Administration (SEPA), 96.9 percent of the Tibetan residents surveyed said they were satisfied with environmental protection along the Qinghai-Tibet railway.

A field investigation along the route found no evidence of damage to the local environment. The landscape, lakes and the frozen earth have been well preserved and wildlife migration patterns have not changed, according to a panel of officials and experts from the SEPA and the Ministry of Railways, as well as Tibet and Qinghai Province.

"The railway has greatly promoted the tourism industry in Tibet, along with social progress," said Puncog.

Tibet will receive six million tourists and notch up at least six billion yuan (US$770 million) of tourism income in 2010, at least 12 percent of the region's gross domestic product, the regional government has said.

The railway has brought an influx of tourists, which totaled more than 2.5 million last year, including 154,800 from overseas. They spent 2.77 billion yuan in the region.

This year Tibet expects to host three million tourists and bring in 3.4 billion yuan of tourism revenue, said Jin Shixun, director of the development and reform commission of the Tibet autonomous regional government.

In the first five months alone, Tibet received a record 672,000 tourists, up 82 percent from the same period of last year.