International Herald Tribune: In this tiny hamlet in northern China’s wheat belt, Zheng Songxian scrapes out a living growing winter wheat on a vest-pocket plot, an eighth of a hectare carved out of a rocky hillside. One might think he would greet the chance this winter to till new land as cause for celebration. He does not. The new land he was offered normally lies under more than 6 meters, or 20 feet, of water, part of the Luhun Reservoir in northwestern Henan Province. But this winter, Luhun has lost …