File photo taken on Sept. 20, 2015 shows straw checkerboard sand barriers at Haba Lake nature reserve of Yanchi County, northwest China's Ningxia Hui Autonomous Region. Located on the southern edge of the Maowusu Desert, Yanchi County was once poverty-stricken and suffered from desertification. But after years of efforts, the environment there has been restored, and the county has also shaken off poverty. (Xinhua/Liu Quanlong)