Villagers irrigate the farmland in Yinjiang Tujia and Miao Autonomous County in Tongren Prefecture, southwest China's Guizhou Province, August 1, 2011. The severe drought in Guizhou, caused by low level of rainfall and heat, affected more than 8 million people in 37 regions here. China's Ministry of Civil Affairs and National Disaster Reduction Committee launch the national fourth level disaster alert to assist disaster relief work. [Xinhua]