Chinese scientists said on Wednesday they have refixed the sources of the Yangtze River and the Yellow River, two longest waterways in the country, after a 40-day survey last year.

The origin of the 6,300-km Yangtze, should be the Damqu River, rather than the previously thought Tuotuo River as the former was longer and bigger in flow and drainage area, according to the research results of the three rivers -- the Yangtze, the Yellow River, and the Lancang River.

For similar reasons, the Kar River should be the source of the 5,464 km-long Yellow River, researchers said. The Marqu River was previously believed to be the source of the Yellow River.

Researchers for the first time identified the Zayaqu River, from the Qinghai-Tibet Plateau, as the source of the Lancang River, which is called the Mekong after it runs into Burma, Thailand, Laos, Cambodia and Vietnam in southeast Asia.

The survey was conducted from September 6 to October 16 last year. The 40-member team consisted of experts and scholars from the Chinese Academy of Sciences, colleges and other institutions.

Tang Qianli, survey leader, said the team used advanced technologies, including a global positioning system, geographical information system and remote sensing to ensure the data were "comprehensive, scientific and authoritative."

The research team collected the data of meteorology, hydrology, glaciers, geology and geography in the origin areas, which was important to world geography, experts of the appraisal commission said.

The results would be announced by the State Council after passing a review by the State Bureau of Surveying and Mapping, Tang said.

(Xinhua News Agency July 22, 2009)