In Ningxiang county of Changsha city, Central China's Hunan province, many hills have been carved away by local factories. The site is among of many scattered in mountainous areas of the county. The high profit margin – up to 50 percent -- has spurred a rampant exploitation of sand resources from the local mountains, resulting in serious soil and water erosion. Many unauthorized sand extraction plants have emerged in recent years, along with officially approved plants, forming a prosperous sand industry in the county. The severe deterioration of the environment has prompted many locals to call for a crackdown on the exploitation and save their green mountains and clean water. [Photo by Xiangyou/CFP]

A sand extraction plant operates in the hills of Ningxiang county in Changsha city, Central China's Hunan province, on Jan 20, 2013. [Photo by Xiangyou/CFP]