KUNMING - An ox-cart rode along a bumpy road in the suburbs of Yunnan's provincial capital, carrying a woman and her thirsty 9-year-old son to a water reservoir several kilometers away.

For more than an hour, no one spoke. The rattling of the cart almost echoed on the long and empty stretch.

The cart stopped at the Tuanjie reservoir. The woman and her son rushed toward the water, as if their throats had been parched for days.