Land Use Change and Its Impact in the Eco-environment on the Yellow River Source Region Dring the Past 15 Years

Based on 1986 TM and 2000 ETM datum,the land use and landscape pattern change of the Yellow River source region were studied in macro-scale by ArcInfo and landscape ecology methods. The results showed that significant changes have taken place in the past 15 years. Construction land,unused land and cultivated land area increased rapidly. Grassland reduced and increasingly changed into unused land. Wetland and the forest land decreased obviously, and the comprehensive land use index reduced by 0.11. The landscape fragmentation degree,the fractal dimension and the diversity index increased,which imply the enhancement of landscape heterogeneity. The eco-environment in the study area was very vulnerable and sensitive to the land use change,which resulted in land desertification\, soil and water loss,and degradation of high-cold meadow vegetation and wetland. Abnormal climate was the inducing and key factor,and irrational human being activities and rat damage were aggravating factors lead to these changes.