Digital Change Analysis and Expansion Monitoring of Urban Areas Using Satellite Images

Digital Change Analysis and Expansion Monitoring of Urban Areas Using Satellite Images

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Abstract
Meysam Argany
University of Tehran,
Iran
Email: [email protected]

M. Reza Saradjian
Co-Author
University of Tehran
Email: [email protected]

The present study indicates that remote sensing data may be used as a valuable tool to monitor urban expansion in some small towns turning to major cities. The highly detailed land-use classification of the agglomeration in Karaj region located at the west and nearby Tehran for instance, and its change extraction can be used as appropriate data input for preparing the necessary development and management plans. The increase in residential area or overall expansion of built-up land in the region and the according statistics extracted from this study may be considered as an alarm for the problem of increase in population, pollution and exploitation of resources in Karaj city.Based on this preliminary case, the expansion of the region has been studied for period of years. The method used is based on multi-temporal and multi-spectral satellite data. In this study, the possibility of using Landsat satellite images for documenting the expansion of built-up areas has been examined. At the initial stage, two TM images with 13 years time interval have been preprocessed. In the next stage, Maximum Likelihood Classification (MLC) technique has been applied on the images. The resulting two classification maps have been compared by applying post-classification comparison change detection technique in which its relevant change detection matrix has been used. Due to the six main classes identified, the relevant change detection matrix contains 30 off-diagonal components with corresponding brightness values. By selection of each component, one of the from-to classes of change information is provided. According to the study, it is concluded that considerable amount of from-to classes may be produced from which useful information necessary for management and development of the city may be extracted. Since the study has demonstrated potential as a means to detect, identify, map and monitor the changes, it is also concluded that the expansion of the city is about 12 percent compared to the first date image; and that the city expansion is mainly due to the lands changed from bare land or vegetation around the city to built-up areas.