Research On Dynamic Monitoring Of City Land Use Based On RS Technology

With the development of urbanization, the demand for construction sites is increasing, especially urban land is growing rapidly. In recent years, urban construction takes on an unhealthy tendencies only for bigness , the size of the cities expand like "spreading out pie", and about 10% of the land is idle in cities, especially in the new city, idle land as high as 15%. Plot ratio of used land is so low. According to the relevant statistics, per-capital construction land is 113 m2 in China's 664 cities, but per-capital urban land is 88.3m2 in developed countries in the world, so urban land area in China in much higher than that in developed countries. This is a severe challenge for our country whose per-capita land resources is lower than the world's average level.From 1997 to 2004, China's annual addtional construction sites amounted to 4.67×104hm2. One side, per capita land area of the city has far exceeded its normal substantial and much land is idle. The other side, construction sites is incresing for the consecutive 7 years. Although it is affected by policies, marketing and planning, but the real-time monitoring to urban land use changes behind of the land use changes is one of the important reasons. Based on this, the paper chooses Changchun City as an example to carry out urban land use dynamic monitoring study by RS technology.The paper first reviews developments of RS technology in the land use dynamic monitoring at home and abroad , and states the purpose and significance of writing. On this basis, with 2005 and 2006 SPOT-5 panchromatic images and multi-spectral images data, the study produced remote sensing orthophoto maps of 2.5 m resolution whose area are complete. By computer automatical extract technology such as margin, spectrum variability and so on, the study contrasted the two orthophoto maps of Changchun in 2005 and 2006 .The study found change information of texture in the image through the use of two satellite data and extracted information which changed in the image. Through field verification, the study confirmed change information of construction sites in Changchun. Through the remote sensing monitoring, the study gained the informatinon of additional construction sites of Changchun in 2006.The study analysed the number,types and infield occupied of additional construction sites in Changchun by statistical analysis. In the end the study carried out the characteristics of additional construction sites, and proposed the the systemic concept of upbuilding dynamic remote monitoring database for land-use. The study provided scientific methods for the application of RS technology in urban land use dynamic monitoring and informatization of land resources management.