Photo taken on Sept. 9, 2015 shows sand prevention and sand fixation installations in Guinan County, northwest China's Qinghai Province. Sanjiangyuan, which translates as "source of three rivers," is home to the headwaters of the Yangtze, Yellow and Lancang (Mekong) rivers in northwest China's Qinghai Province. Ecological construction has been going on since 2005. (Xinhua/Wu Gang)