Eastern regions would be prone to drought, which could raise the risk of forest fires.

Meteorologists said the adverse forecasts were related to the La Nina weather phenomenon.

But decades of overgrazing and deforestation mean that China is also fighting to contain its deserts, whose spread has helped fuel the sandstorms that lash the country's north every spring and whose effects are felt in South Korea and Japan.

Beijing has pledged to hold a sandstorm-free Olympics come August, and has launched campaigns to restore denuded land and plant trees, with its noxious air quality a major concern for both athletes and organisers.