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Nowadays, Spatial and social inequalities are universal and expanding phenomenon. Identification and spatial analysis of social, economic and ecological inequalities in metropolises is one of the essential and basic proceeding for planning and achieving urban sustainable development. The present research method is descriptive-analytical and using 13 sub criteria based on three main criteria of social, economic and environmental analyzes the status of spatial fragmentation among the metropolis Tehran's districts. For this purpose, the criteria and sub- criteria's internal and external dependencies was determined using the Delphi and ANP method in Super Decisions Software and assessed and scored relative to each other. The results of assessing the indicators shows that Tehran metropolis lacks of the physical unity and spatial heterogeneity between the north and south of the city remains as main feature of its spatial structure. It is necessary that the authorities of Tehran urban management to take actions for better understanding of this phenomenon and consequently offer new and efficient solutions for reducing the effects of various impacts of spatial inequality and duality. For this reason, it is essential to rethink the concept of city in terms of social, economic, political, and ecological and sustainability dimensions.

The questions of centralization and decentralization arise in every polity. The constitution or the practice or both have to settle how much of policy making is to be decided by the central government and by component bodies. By and large liberalism and decentralization tend to go together while authoritarianism tends to be associated with centralization. The constitutional model which is generally regarded as bringing about the largest amount or decentralization is federalism. This is said to sonstitute a half way house between confederacies (where component units dominate)and unitary states (where the center dominates) In its classical form at least , federalism stipulates that there have to be two independent levels of government (the centre and upper level component bodies (often named states) each of these levels has the right to decide on matters falling within its own sphere. There are difficulties in practice especially with respect to the constituent power and to the fields allocated to each level. Federalism must be based on a rigid constitution there has to be s supreme court protecting the independence of the two levels of government there has to be a second chamber defending the rights of the component bodies at the central level.yet there are variations in the extent to which the component bodies are protected and generally in the extent to which there is decentralization. On the one hand federal states are becoming more centralized on the other centralization cannot go beyond a given point without leading to gross inefficiency and perhaps to a break up of the regime as the communist experience showed. Partly for this reason there is a degree of convergence between federal and unitary states. Federalism is also associated with efforts to bring together independent states but this has occurred in a smell number of polities only. Attempts at achieving closer cooperation between states has led more commonly to confederacies, such as the Unites Nations. The European community or European :::union::: has innovated by forming a type of association labeled supranational which is intermediate between the confederal and the federal models. There is innovation in that developments take place gradually with new fields beings progressively covered new structures being set up and new member states joining. The problems of centralization and decentralization have exercised the minds of many in relation to many types of organization : both efficency and freedom appear to be at stake . federalism succeeded in a number of contexts but it is not the panacea which some suggest it is it is also so diverse that one has to refer to federalisms rather than to federalism . what is at stake is the need to find an equilibrium between the two extremes of over centralization and break up. Given the large number of situations in the contemporary world one should look for a variety of solutions and for a continuous evolution of the models which have hitherto been proposed.