Beijing, June 4 - China may face huge flooding this year due to increased rainfall, an official said.

Floods have already occurred in areas along the Yangtze river tributaries this year.

The water level on middle and lower reaches of Yangtze was one to three meters higher than the historical average, said Wu Daoxi, in charge of Yangtze flood control office.

The Yangtze river valley was last hit by massive floods in 1998 when some 4,000 people died. The chance for large-scale flooding is significantly higher now, Wu said.

Precipitation levels are likely to increase by 20 to 50 percent above normal in Huaihe and Yellow river valleys this summer, Xinhua reported.

Authorities have discharged water from some reservoirs, including Three Gorges reservoir, to prepare them for storing floodwaters.