Poyang Lake,located in Jiangxi Province, was once the largest freshwater lake in China.It once had a surface area of about 3,500 km2, a volume of 25 km3 and an average depth of eight meters. As of 2012, due to drought and the practice of storing water at the Three Gorges Dam the size of the lake has been reduced to about 200 km2. The lake provides a habitat for half a million migratory birds and is a favorite destination for birding. It is fed by the Gan, Xin, and Xiu rivers, which connect to the Yangtse through a channel.During the winter,the lake becomes home to a large number of migrating Siberian cranes, up to 90% of which spend the winter there.Now the Chinese scientists will examine Poyang Lake every year.