VISUALIZATION URBAN SPATIAL GROWTH OF DESERT CITIES FROM SATELLITE IMAGERY: A PRELIMINARY STUDY

摘要

Desert cities, particularly those in Asia, are the home of ever-increasing population and emerging production centers. These areas are facing different problems and challenges, such as urbanization, land degradation, water shortage, and climate changes. Mapping and visualizing the spatial growth of urban settlements are a prerequisite to formulate and implement various planning and management activities. In this preliminary study, we discuss a remote sensing-based method to visualize the spatial growth of urban settlements of desert cites from satellite imagery. The case study site is located at the southern rim of the Taklamakan Desert, China. Our preliminary research comprised several major procedures. Firstly, we acquired two predominately cloud-free Landsat images for 2000 and 2010, respectively. Secondly, we conducted image preprocessing that included a procedure of relative radiometric normalization. Thirdly, we derived a normalized differenced vegetation index (NDVI) image from each of the normalized images. Fourthly, we used the two NDVI images to analyze the spatial growth of the oasis. Lastly, we visualized the spatial growth of urban settlements of the desert cities by comparing both the normalized images and the two NDVI images. Our ongoing research will focus on the production of land use/cover maps that will form the basis for a temporal analysis of the urban spatial distribution.