Evaluation and site selection of urban physical developmental directions using fuzzy logic Case Study: Divandareh City

Natural parameters are the main and defining factors in physical development aspects of the cities and habitats. The effects of these factors as developmental obstacles are doubled in a mountainous region and can cause natural hazards. In this study we tried to identify the optimal directions of physical development in Divandareh as a mountainous region through recognizing and evaluation of influential factors. To do so, 10 effective indices are used and for evaluation, modeling and predicting the suitable areas of physical development of the city, the fuzzy logic model is used so that each layer are entered into the ARC GIS 9.3 software. And then product, sum and various amounts of Fuzzy gamma operator are implemented in these layers.. Analytical comparison on suitable zones of the present situation of city based on critical points with appropriate zones obtained from gamma amounts were done in order to select the optimal fuzzy gamma and it was identified that 0.8 fuzzy gamma has the maximum compatibility with the suitable lands for existing condition of the city. Then final map was grouped into 5 classes and it was determined that 24 percent of the study area (28.87 km2) is located in the class with the high suitability. 56.7 percent of the area (68 km2) is located in a unfit suitability class. Based on the final classified map of we can conclude that the suitable zones for future physical development of Divandareh are mostly located in east, partly in northern and south-eastern areas in a disperse manner.