پايش تغييرات كاربري اراضي كرج با استفاده از تكنيك سنجش از دور

Monitoring Land Use\ Land Cover Changes in Karaj By Applying Remote Sensing

The border of land units influenced by human, social, economic events and natural occurrence has been changed mostly based on time and location parameters and partly unplanned. Data according to the environmental conditions are necessary for source management. As it takes a long time and expense to collect data, tools and technologies are applied so that exact and less expense might be consumed. This research focused on land use change in Karaj city, located in west of Tehran interval 1987 and 2002 with applying remote sensing technique and satellite images. Landsats 5 and 7 (ETM+) images used for this study. First the region was extracted then land units classified by supervised classification, brightness and greenness images. The result from various types of classifications compared with each other as well as ground truth, so that the settlement between supervised classifications with land use can be specified. By surveying on the images reveals that magnitude of change this metropolis like the others in the world have high rate changes in social-economic environment and land use. According to the images in 1987, the extent of built-up units includes Karaj city and suburbs and its vicinities were 6032.3 hectares and in 2002 images was 10541.12 hectares. So Karaj city converted to metropolitan and vicinities to towns and cities. The high rate growing of Karaj caused farmlands and orchards transformed to build-up lands. This conversion was happened toward south and west where the lands are more suitable for cultivation and agriculture productions. According to this research, using satellite images for interval in vast areas by various processing methods and classifications are very effective and important and mostly results coincide the facts. Keywords: Land Use, Land Units, Satellite Images, Supervised Classification, Time Intervals