Land erosion is a growing threat to China's food supply and increasing the risk of floods, a report published on Thursday by the Ministry of Water Resources has said.

The report, which followed a three-year government survey, said China now has more than 3.5 million sq km of eroded land, of which 1.6 million sq km is due to water and 1.9 million due to wind.

About three-quarters of the country's poorest people live in areas affected by land erosion, it said.