A staff member of the local water conservancy department examines the channel to dredge up the imprisoned lake at Linjiaba Village of Pingwu County under Mianyang City, southwest China's Sichuan Province, May 21, 2008. The May 12 quake caused landslides in some places in Mianyang City and jammed nearby rivers in the gorges. Over 10 imprisoned lakes of high water level were thus formed. At present, the local water conservancy department keeps a 24-hour watch on these imprisoned lakes in case of floods. (Xinhua Photo)