Introduction: This paper attempts to clarify the effect of dam construction on changes of physical urban development. This research also investigates if the physical development has occurred on scientific

This paper attempts to clarify the effect of dam construction on changes of physical urban development. This research also investigates if the physical development has occurred on scientific rules or not, and finally presents an urban development model.

In this paper, two frames of IRS satellite were used to investigate the urban areas physical changes. One frame was relevant to two years before constructing the Taleghan dam and the other one was relevant to two years after constructing the dam. Then, both frames passed the geometric correction order and after that the border of urban area was extracted. This revealed that the urban areas had more area than before constructing the Taleghan dam. Considering the recent researches, a new fuzzy urban development model was presented and all the weights for being in several circumstances were defined. Using the attributes data, 1:25000 digital maps and the other studies, extraction of the layers required by the new fuzzy urban development model was tried. By overlaying the layers in ArcGIS software, the very unsuitable, unsuitable and suitable areas were detected on map.
Result and

Finally, it was concluded that the areas located on very unsuitable areas must be emptied, and the unsuitable areas could be preserved by some management methods like watershed management. However, there was no more suitable areas for further development of the urban areas. On the other hand, some parts of the studied urban areas have been located on suitable areas. The most important cramp elements for prevention of urban areas development were found to be landuse and vegetation cover. For increasing the capitation of settlement, it is better to develop the existing residential areas by height