Land Use Changes In Comparative Study Based On Remote Sensing Of Kunming City In The Expansion Process

Since the 1990s, Chinese urban construction has been in a rapidly developing period, the urban construction area is rapidly expanding. Land is the foundation of city construction, and rational use of land resources is essential for region's sustainable development. Strengthening effective monitoring of urban expansion and land use / cover, and timely mastering urban land use and expansion trend are very important to rationally planning the land resources and stop illegal sites using timely.The paper researches the main urban areas expansion of Kunming and the change of land use/land cover of research region by using of two land resources satellite Landsat TM data in 1992 and 2004.The researched region include Panlong District, Wuhua District, West Mountain District and Dian Lake. All major work were running supported by professional remote sensing image processing software ERDAS IMAGINE8.5 IRSA6.1By using AOI seed tool generate main urban areas in two period images, and get the statistics: main urban areas was 182.60 square kilometers in 2004 while 90.82 square kilometers in 1992;urban area expanded more than twice in 12 years and the average annual increase is of 8.48 sq km;The trend of main urban expanding is to Chenggong County in Southeast direction, the Jindian in Northeast direction, and Songhua Dam direction.Combining the method of layered classification with the method of traditional supervision classification and make full use of the regrouping among multi-spectral data of TM. I extract construction sites and water bodies from TM145-band images and the remaining category from TM345. It is difficult to achieve precision if you simply use supervise classification to process the masked 2004 image. So I use layered classification that based on supervise classification to mask a land type after finishing a type. Finally we can get classification result by overlay all land type, and the classification precision meets the requirement. According to the classification results, I analyze the quantity and structure changing and mutual conversion of land use of researched region in the 12 years. The results show that land use changes a lot: theareas of construction land increases with the speed of 3.3% per a year, and occupy lots of tilth;the areas of woodland and grassland rising a lot is the result of attaching importance to tree planting and afforestation, returning land for farming to forestry. Correspondingly, the areas of tilth and unused land decrease a lot, the decreasing rate were 32.9% and 65.1%;waters of the area also show a declining phenomenon.