Remote Sensing Monitoring Of Urban Expansion In Different Scale Of Karst Mountainous Areas

Along with the western development strategy vigorously advancement, the Yunnan area social economy has obtained the remarkable achievement, the urban construction and the development footsteps speeds up gradually. South-east Yunnan Karst Mountains is located in south-eastern of Yunnan Province. Because of its typical karst fragile environment and the complexity of the land resources, the region’s land resources are scarce, and relationship between people and land relatively tight. Urbanization brings prosperity to these areas at the same time, but also puts tremendous pressure on the environment. Therefore, the karst mountain areas of town change research more effectively reveal the social and economic factors impact on the sustainable utilization of land.Based in karst mountain area of Southeast Yunnan Mengzi city, Yanshan County, and Ba bao town three dimensions as a study area, taking the TM/ETM+ and OLI/TIRS remote sensing image as the basic data, using ENVI5.1 and the ArcGIS10.0 software, unifies the remote sensing technology and the GIS space analysis, the contrast has analyzed the different criterion research area in the near for 23 year cities change as well as the expansion situation.Combined maximum likelihood classification with hierarchical information extraction method and visual interpretation of extraction based on different scale of urban land use information, the paper achieves town changes process monitoring result and analysis of the status of land using the scale of the study area, also summarizes the characteristics of land use in karst mountain area, and uses the transfer matrix to calculate the structure change of land use in various scales study area:Various scales study areas’structural change are obvious, in which the forest land structural change is most remarkable. Build the dynamic index and degree change model of land use, the results showed that with the increase of time and scale, degree of land use change is becoming more intense.Land use degree ofcity scale and township-level scale has changed from variation phase to development; land utilization degree in the county level has remained in development phase.Secondly, use the GIS spatial analysis technology to extractconstruction land in built-up area and analysis the spatial and temporal characteristics of built-up area expansion.The time process analysis selected the yearly average of expand rate and expansion intensity index; the spatial process analysis has selected the spatial quadrant analysis, the fractal latitude index, the compact index and the center of mass shift index.The following results are:(1) Time process analysis:Built up area within the same period with the decrease of the scale in the annual construction land expansion rate is falling, but different scale annual expansion rate change trend in the study area.City-level area of study in the years 1990 to 2007 are medium-speed expansion type,2007 to 2013 in a rapid expansion mode.County-wide scale research areas have been expanding at a moderate speed, and township-level scale from low speed to slow expansion in the study area and finally to medium-speed expansion mode.(2) Spatial process analysis:The construction land in City scale built-up areas expands to westward, the most significant of which is the direction. The country scale expands to east and northeast. Township-level scale is mainly affected by traffic road to the northwest and southeast two relative to the direction of expansion.The city level and the county level criterion research area construction use the shape to become gradually complex, and more and more deviates compact The villages and towns level criterion research area gradually becomes the simple city internal structure while the built-up district boundary even more to be more compactCity scale and the scale of construction land expansion in the study area at the county level shall type expansion.The villages and towns level criterion research area central cities expansion way packing type expansion and the extension shaft type expand the primarily mix expansion pattern.City scale and the scale at the county level city center of gravity respectively to the northwest and northeast direction, two center of gravity and township-level scale movements are small, first northwest to the southeast direction deviation.To affects the karst mountainous area cities expansion to carry on the driving influence analysis.Obtaining:The city level criterion and the county level criterion research area cities expand the major effect factor is government’s decision-making and the economic development, the natural factor and the traffic factor become affect the main factor which the cities expand.