Ecosystem Construction Effects in Southern and Northern Mountains of Lanzhou by Remote Sensing Monitoring

Based on the Landsat ETM+ images in 1999,Landsat TM in 2005 and Environment and Disaster Monitoring Small Satellite images in 2009,the land use data of the three periods in southern and northern mountains of Lanzhou were extracted.The variations of land use and landscape pattern in southern and northern mountains of Lanzhou during 1999—2009 were analyzed based on the land use data and GIS analysis,landscape indices calculation and mathematical statistics.The results showed that,in the past 10 years,forest and residential lands increased obviously,grass land and farm land decreased;Landscape pattern tended to fragmentation,landscape diversity increased,and landscape structure tended to diversity and homogenization.The analysis of driving forces showed that the human activity and policies were the main affecting factors which led to changes of land use and landscape pattern.