Southwest China's Tibet Autonomous Region maintained sound environment last year thanks to a series of protection measures, a report issued by the local environment watchdog said Friday.

Tibet's 2010 environment status report said the region reported progress in environment protection, as its water and air quality indicated.

Last year, the water quality in Tibet's major rivers and lakes, including the Yarlung Zangbo, Lhasa River and Rongpo River that originates in Mount Qomolangma, met national standards for clean water, the document said.

Meanwhile, all Tibetan cities and towns reported good air quality last year.

The regional capital Lhasa reported good air quality on 98.9 percent of the days in 2010. In Tibet's second largest city Xigaze, air quality was good on 99.5 percent of the days.

In Bayi town of Nyingchi Prefecture, air quality was good all during the year.

The report attributed the good air and water quality to effect environment protection.

"Effective measures were taken to protect the pastureland, forests, wetlands and bio-diversity and curb pollution," the document said.

Last year, the regional environment protection administration closed down nine ore concentration plants to curb pollution.

Another 26 ore concentration plants and 16 mines were suspended production for overhaul, said Jampel, deputy chief of the regional environment protection administration.

He said Tibet had banned ultra-thin plastic bags and lunch boxes and started building three garbage treatment plants in Nagqu, Qamdo and Ngari prefectures.

Another 14 garbage treatment plants will be built in 14 counties across the plateau region, he said.

To expand the region's forest reserves, an additional 60,000 hectares of trees were planted in Tibet last year and 4,000 hectares of cropland was reclaimed to forests.

Last year, Tibet set up three new nature reserves and spent 20.7 million yuan (3.2 million U.S. dollars) to improve rural environment in 26 villages.

Meanwhile, the region spent a total of 780 million yuan to preserve its natural forests, wetlands and wildlife, prevent forest fire, plant diseases and insect pests and promote clean energy in nomadic communities.

Experts say environment protection on the Tibet Plateau, dubbed the "roof of the world", is essential in fighting glacial melting and climate change.