Monitoring Rapid Urban Expansion of Tehran
Following DEWA~wide efforts to document environmental changes during the last thirty years in selected sites around the world, several satellite images of Tehran were studied at GRID-Europe. The rapid expansion of Tehran, as well as its sharp population growth in recent decades, has had many adverse impacts on the environment. Three satellite images from the years 1975 (Landsat MSS), 1988 (Landsat TM) and 2000 (Landsat ETM) were used to study this phenomenon.
Tehran is located at the foot of the Alborz Mountains. The city occupies the northern part of the alluvial Tehran Plain, sloping from the mountains to the flat Great Salt Desert. The urban area is bounded by mountains to the north and east with the ground sloping southward falling 800 m over the 25 km from the northern suburbs to Shahr-e-Rey in the south. This geographical situation of the city makes it difficult to differentiate the urban area from the mountainous and desert area that surrounds Tehran.
Different remote sensing techniques were applied to carry out the land use/cover change detection using multi-temporal Landsat Thematic Mapper data. Analysis of the resulting land cover maps showed that the physical growth of the city is replacing other land cover classes such as farming, water resources, etc. A map of historical growth of Tehran was geo-rectified, compared to the images and the urban growth patterns were analysed using a GIS-based approach. The results reveal a notable and uneven urban growth in the study area. More detailed results will be published soon.
Research conducted by:
Saman SALARI SHARIF, GRID-Europe