'Sponge cities' plan to reduce flooding

When Wei Yingyan poured a bottle of water onto the ground at the Yuelai Convention Center Park in Liangjiang New Area in the southwestern municipality of Chongqing, the liquid disappeared into permeable pavements within seconds.

"During heavy rainfall, the water is soaked up by the porous bricks and flood-tolerant plants to prevent flooding," said Wei, urban design director of Chongqing Yuelai Investment Group. "We collect and store most of it, then use it for irrigation or cleaning."

The park is a showcase for China's urban-planning efforts. In recent years, poor drainage systems and a rise in the number of extreme weather incidents have resulted in many cities experiencing heavy rain and flooding.