China has spent 4.55 billion yuan ($713 million) on conservation work to preserve the source of the Yellow, Yangtze and Lancang rivers, a local conservation official said on November 30.

The ecological conservation program, initiated in 2005, possesses a budget of 7.5 billion yuan ($1.15 billion) and aims to halt degradation of the environment in the threeriver region in northwest China's Qinghai Province. The investment has funded grazing bans, pasture conservation projects, inhabitant resettlement and artificial weather control.