Monitoring Of New Construction Land Using High Resolution SPOT5 Imagery

One of the basic national conditions of China is much Population with less land. In recent years, with the rapid development of economy and the improvement of urbanization, construction sites are increasing rapidly while farmland and unused land are less and less, so the contradiction has manifested itself between land resources and the development of social economy, especially in urban areas: the construction sites grow rapidly in the form of extensive land use, and lots of farmlands are occupied, as a consequence, the rational utilization of land and the sustainable development of the city are seriously affected. For the purpose of strict land management, using land more economically and intensively as well as improving the efficiency of land use, various regions widely develop land resources surveys. Based on this, the paper chooses Taian city proper as an example to carry out dynamic monitoring study of new construction sites by"3S"and the survey measurement technologies, so as to provide accurate informative basis for land resources management.Based on the research methods of both domestic and foreign remote sensing monitoring, the study produced remote sensing orthophoto maps of research area with 2006 and 2007 SPOT5 panchromatic images and multi-spectral images data, and then used the computer automatic extraction technology and man-machine interactive visual interpretation method to extract change information, so as to realize remote sensing dynamic monitoring of urban construction sites, arable land and other kinds of land. During the process of producing orthophoto maps, the paper systematically expounded theories and methods of the images registration, images fusion and ortho rectification: based on image matching method, it took 2006 SPOT5 panchromatic images as the reference to registering other related data; then carried on experimental comparative analysis and effect appraise to four common methods of image fusion, and chose PCA transformation method as the main method; in order to improve image distinguishing accuracy, the images were put into ortho rectification. On the base of image processing, change spots were extracted with man-machine interactive visual interpretation method, which was helped by computer automatic extract technology such as image margin, spectrum variability and so on; then according to relevant datum and statistical data to carry out field investigation and late-stage indoor work, so that the types, places and other attributes information of change spots can be defined, moreover, to establish the database of urban new construction sites, output maps and count statistic monitoring results.The results of research indicate that: (1) The monitoring accuracy accords with the requirements: the error of orthophotomap is within one pixel limits,also,the attribute and area errors are not more than 10%, and these errors have be avoided through field confirmation; (2) During the monitoring period, new construction sites cover an area of 2413.39 mu, the number of change spots is 102, and the change extent of District de Daiyue significantly greater than District de Taishan's; (3) New construction sites have five types, including industrial warehousing land, residential land, business land and so on; (4) From the time, the annual change of construction sites is reasonable, and has an increasing trend; from the space, new construction sites are located in the integration of urban and rural or suburban areas, and mostly distribute along the main roads, factories and residential land use, etc; (5) The main driving forces of new construction sites are economic and social development, urban construction, demographic factor and planning policy. Finally, according to the change reasons and related problems, the paper puts forward four feasible measures, to make referential suggestions for land resources management.