Scientists from Chinese Academy of Sciences(CAS) Tuesday said they had made the first satellite map of China's wetland areas, in order to better monitor and manage the areas.

The map, which took scientists two years to complete, comprises 600 scenes of satellite images with each scene covering an area of 34,225 square kilometers, said Gong Peng, chief scientist of the project, who is also a researcher of CAS's Institute of Remote Sensing Applications.

According to statistics from the institute, China has a natural wetland area of 308,000 square kilometers as of 2000, including natural lakes, marsh, shallow water along the coast, and inter-tidal shoals.

"The number shows a 50,800 square kilometers decrease compared with the data collected ten years ago," said Gong Peng.

A wetland is an area of land that is saturated with moisture. China has 38 national wetland parks, and more than 550 natural wetland reserves, holding 2.7 trillion tonnes of fresh water.

Wetland areas in China are mainly in Tibet and Inner Mongolia Autonomous Region, and also Qinghai and Hei Longjiang provinces.

"Right now the number of natural wetland areas are reducing, while the constructed wetlands are rising, which is due to the increase of aquaculture areas in some eastern China provinces where fishermen make aquaculture business," Gong said.

"But the newly added areas have limited function and cannot displace the effect of the natural wetlands," Gong added.

Chinese government earmarked 16.5 billion yuan (2.4 billion U.S. dollars) to protect and restore wetlands during the 11th five-year plan period (2006-2010).

(Xinhua News Agency February 18, 2009)