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中国黄土高原面积40万平方公里,是地球上最大的一片黄土地。一般海拔800～2000米,黄土层平均厚50～80米,最厚100～200米。土层由碳酸钙胶合而成,貌似岩石,实际疏松易溶,遇水即化解成泥。史前时期,高原在森林、草被的保护下,原面完整,生态和谐。5000年前开始了人类改造高原的进程,无节制的伐木、垦荒和连年战争,破坏了植被,完全改变了高原面目,留下了“千沟万壑”。目前除高原中央还保留较完整宽阔的原面
China’s Loess Plateau covers an area of 400,000 square kilometers and is the largest yellow earth on the earth. The general elevation of 800 to 2000 meters, the average loess 50 to 80 meters thick, the thickest 100 to 200 meters. Soil layer is made of calcium carbonate glued together, looks like rocks, the actual loose and soluble, water to dissolve into mud. Prehistoric period, the plateau in the forest, grass under the protection of the original integrity, ecological harmony. 5,000 years ago, the process of human transformation of the plateau started. Uncontrolled logging, reclamation and successive years of war have destroyed the vegetation and completely changed the face of the plateau, leaving “a thousand gullies.” At present, in addition to the central plateau also retains a more complete and wide original