我国已治了半个世纪的沙，可为什么沙漠化土地面积越来越大？边治理边沙化、治理的速度赶不上沙化的速度。原因是多方面的，“治而不防是主因。２０世纪５０年代，中科院兰州沙漠所经过调查，当时土地沙漠化扩大有以下几个原因：滥樵、滥垦、滥牧、滥用水资源、滥采（采矿、采 China has been treated for half a century of sand, why the area of ​​desertification is growing? While desertification control, the pace of governance can not keep up with the speed of desertification. There are many reasons for this: “Governance is not the main cause of failure.” In the 1950s, the Lanzhou Desert Institute of the Chinese Academy of Sciences was investigated. At that time, there were several reasons for the expansion of land desertification: abuse of firewood, indiscriminate cultivation, overgrazing and abuse of water resources Mining (mining, mining