Study On The Land Use Change Analysis And Evaluation Of The Rationality Of Lanzhou City

Land use change is an important part of global environmental change, since the 21 st century, the research of land use change has been the geographical frontier and hotspot in the research of the related disciplines. As one of the important cause of the change of the environment, land use and are at the mercy of many factors, through the study of land use change and its driving force, reveals the change rule has become the times required.Based on typical valley northwest city of lanzhou city four area as an example, based on remote sensing and GIS spatial analysis technology, the introduction of flow analysis and the analysis of land use activity, study 25 years from 1985 to 2010 of lanzhou city land dynamic change, through the measure of land use change model and principal component analysis method, analysis of time and space dynamic characteristics of land use and its driving mechanism, based on the TOPSIS method to evaluate lanzhou city in 1996-2010, reasonable land use degree. The results showed that:(1) Between 1985-2010, the transfer of land system flow is mainly concentrated in lanzhou urban area: the cultivated land, construction land, forest land and grassland. In urban development and construction of a large amount of land occupied and cultivated valley quality, cultivate the grass at the same time, this led to the mode of land use changes frequently, especially in this period from 1996 to 2010, with the rapid urbanization, lanzhou city land transfer flow increases rapidly, increased the instability of land system.(2) Through to the lanzhou city in 1996-2010 land change driving force on the principal component analysis, found that spending And the total investment in fixed assets of lanzhou city land system stability weight is as high as 0.915, 0.886, respectively, the influence of the construction of this shows that the government behavior has significant effects on the stability of lanzhou city land system is greater than the other social and economic activities.(3) From 1996 to 2010, lanzhou city of evaluation results of land use structure is reasonable, in the evaluation of land use structure reasonable degree during the period of time has obvious volatility and stages. According to the degree of land use structure and reasonable time to evaluate the effect of land use policy and its impact on land use structure is to promote land use structure reasonable degree of the effective ways to improve.