Global warming and overdevelopment have decreased the water storage capacity of the Yellow River in Maqu, Gansu Province, local weather authorities have said.

The flow of the country's second-longest river in Maqu has slowed by 64 percent, compared with the 1980s, while grassland and wetland areas have shrunk by 45 percent, according to the Gansu Provincial Meteorological Bureau.

The Yellow River originates in Qinghai Province, which neighbors Gansu. Maqu functions as a basin for the river because of its substantial grasslands and wetlands.

The length of the Yellow River in Maqu exceeds 430 km.

Research by the meteorological bureau and local authority suggests global warming has adversely affected the permafrost layer, which decreased from 120 cm in the 1970s to less than 70 cm.

Thinning of the permafrost layer decreases the soil's water storage capacity as water evaporates or filters underground.

Slowing of the river is also a factor. In the 1980s the river flow was calculated at around 3.85 billion tons annually, but in 2006 the figure was 1.38 billion tons.

Development of the area has also caused deterioration of the wetlands and grasslands habitats in Maqu.

Experts believe that if the wetlands continue to shrink and water sources dry up, it will endanger the ecology of the entire Yellow River Basin.

"The region's function as a reservoir for the Yellow River has decreased significantly," deputy director of the meteorological bureau Zhang Qiang said.

As a result local government officers in Maqu drew up plans early last month to protect the area's environment.

Gansu has earmarked 6.6 billion yuan (US$877 million), until 2020, on wetland protection in Maqu, according to Yang Yong, deputy director of the Regional Sector of Gansu Provincial Development and Reform Committee.

The project has two phases, with the focus on grassland recovery and wetland protection from 2007 to 2010; water conservation and replenishment from 2010 to 2020.

"With the completion of the project the environment is expected to improve greatly," Zhang said.

(China Daily September 13, 2007)