Tibet's Potala Palace, photographed on March 27, 2013. Air quality in Lhasa was heathy 94.5 percent of the time during last year with an annual average PM2.5 level of 26. [Photo/Xinhua]

LHASA - China's Tibet autonomous region will plant more than 66,666 hectares of trees this year as part of an afforestation project covering six rivers in the region, local authorities said Thursday.

The local government plans to invest a total of 30 billion yuan (about $4.9 billion) in the project covering the Yarlung Zangbo, Ngulchu, Lhasa, Nyangchu, Nyakchu and Sengye Khabap rivers, according to Lei Guilong, head of Tibet's forestry department.

The project will begin in 2014 and is expected to be completed by 2030.

Lei said that in addition to the area along the six rivers, the forestry department will also increase greeneries along highways.

He said that a total of 11,200 hectares of trees will be planted this year near airport roads in Mailing, Gonggar, Xigaze, Bangda and Gunsa and the expressway linking Lhasa and Nyingchi.

Statistics show that Tibet planted 67,866 hectares of trees in 2012 and 69,600 hectares in 2013. The government of Tibet plans to increase the region's forest coverage by 260,000 hectares from 2011 to 2015.