"A survey conducted from November 2003 to April 2004 on desertification and “sandification” (the stage of soil erosion preceding desertification) found that 27.5% of China’s land area would be desert by the end of 2004, while sandification would have spread to another 18.1%."
Source:
http://www.japanecho.co.jp/sum/2005/320507.html