| Based on the concept of land desertification and the theory of geological environment and its evolution, this paper points out the developmental periods of land desertification, discusses the geological background for the formation, development and evolution of land desertification, the macro-controlling factors of its distribution regularity, and the geological, hydrogeological as well as environmental-geological conditions and their effects on the extension of land desertification. Finally, basic countermeasures to land desertification are put forward. |