Study of Effective Factors on Sprawl Growth of City in Tabriz City by Using of Evaluation Models for City Expansion

There is a meaningful relation between city form and level of stableness. Recognition of morphology and explanation of its growth pattern will be an important stage at certainty of city stableness. So, planning politics, guidelines and also designing should be in a way that formation of a city will be as we wish. Among stableness patterns which discussed at the late 20th century, more focus was on form of compacted city. As the reason, this pattern could be able to attract more partials to itself and placed at the first level in discussions related to the form of city stableness. Thus, we chose this study to reach to our purpose in which we analyzed and evaluated effective factors on sprawl growth of city in Tabriz Zone. After that a suitable model was presented as a basis theory and navigator this study to control stableness. Because of expanding the subject of city intelligent growth, we decided to choose a dimension of this pattern among its different dimensions which we can discuss and analyze. That dimension relates to density indexes and it is supposed as the solution and way to reach to our purpose. To analyze and evaluate effective factors on sprawl growth of city in Tabriz Zone, we used suitable models and methods in this field. As the result of investigations, at first, we found that the first level of city growth was because of situation of relation and natural growth of population. This kind of growth was according to the natural and district specialties. After a while, growth of city was because of different factors such as economics, politics, designs, programs and other factors. At the end, these factors caused Tabriz to be a sprawl city. Some of the important factors are the worth of ground and housing inside part of Tabriz, speculation, buying and selling ground, underdevelopment of Tabriz in legal part on the whole, letting all part of city by at least 10% of housing, legible part in Tabriz in comparative design in some villages such as Gogvar, Ogli, Alvarolia, Kondrod, Khalegan, Anakhatoon and the last factor is demand to have more room for living.