WIND-ERODED AND SANDIFIED LAND AND ITS CONTROL IN STEPPE REGION OF ORDOS
鄂尔多斯草原地区土地风蚀沙化及其防治

Steppe region of Ordos in China is the most serious area suffered from wind erosion and sandification. The processes of wind-erosion and sandification of land and its recovery is in progress alternately.The processes in occurrence and development of wind-erosion and sandification of land may be divided into four historical periods: (1) ecological balance was destroied and land came to be wind-eroded and sandified in the late Surpleistocene Epoch of Quaternary Period; (2) ecosystem balanced, wind erosion reduced and shifting dunes fixed naturally in Holocene Epoch of Quaternary Period; (3) ecological balance was destroyed again, wind erosion developed and shifting dunes recovred after 500 A. D.; (4) ecological balance has been destroyed seriously and the area of wind erosion and sandification have expanded rapidly since 19th century A. D.Modern processes of wind erosion and sandification can be divided into three main types in the light of main land differentiation, that is, ridgeland, fixed sandyland and hollowland. Each type can be divided into four stages according to the degree of wind erosion and sand cover, i.e. slight, moderate, severe and ultra-severe.To adopt measures of artificial sand-fixation and growing grass by closing sands can rapidly make the recovery of vegetation and soil on the wind-eroded and sandified land in the Ordos steppe region, and the shifting dunes could be fixed and semifixed in about ten years.Rational use of land is the effective measure to control wind erosion and sandification and to mantain ecological balance beneficial for mankind.