BEIJING - The national flood and drought prevention office has warned that severe floods are more likely to occur this year due to markedly increased rainfall, according to Sunday media reports.

Floods may cause greater damage this year and the possibility of massive floods along the country's rivers cannot be ruled out, the office of the state flood control and drought relief headquarters was quoted as saying in a report by the People's Daily.

Floods have occurred along several tributaries of the Yangtze River, China's longest river, on a dangerous scale during the current flood season, the report said, quoting Wu Daoxi, an official in charge of the Yangtze River flood and drought prevention office.

Water levels on the middle and lower reaches of the Yangtze are one to three meters greater than the historical average, Wu said.

The Yangtze River valley was last hit by massive floods in 1998. The chance for large-scale flooding is significantly higher now, Wu said.

Heavy floods are also likely to occur along the Huaihe River, a major waterway in central China, the report quoted Zhang Jiatuan, deputy head of the state flood and drought prevention office, as saying.

The report said precipitation levels are likely to increase by more than 20 to 50 percent above normal levels near the northeastern end of the Huaihe River and the Yellow River valley this summer.

The Pearl River, China's third-longest river, will probably see regional floods or droughts in its valley this year due to the unbalanced distribution of rainfall, the report quoted Liu Zhisen, a hydrology official from the Pearl River water resources commission, as saying.

Authorities have discharged some water from mid- and large-sized reservoirs along the Yangtze River, including the Three Gorges Reservoir, to prepare them for storing floodwaters, according to the report.

The Chinese government has spent heavily on dam and dike projects after massive flooding on parts of the Yangtze River killed 4,150 people in 1998.