Studying and analyzing the role of rural migrations in creating the informal section (case study: Tabriz megalopolis)

City or polis, as a dynamic system, is continuously varying and changing. In some ages of history some events, as inflexion point, have caused sudden, immediate and unexpected transitions in form and spatial construction of cities. In the meantime, the land reform had the basic role in the immediate progression of cities, and caused unplanned migration of rural people to cities. This article evaluates the economic roots of this problem on the basis of urban sustainability views to provide a proper context for better realizing and judging when they are applied in urban planning fields. This research is of application – development kind, and its method of study is descriptive – analytic. The method applied here is also based on field operation (direct observation, filling various questionnaires) and the use of available documents. The statistic community of the research involves (n) hundred thousand people and according to the formula of Kokran, the estimated number of sample volume (N) was 390 people. The method of sampling is of accidental – bunching and multistage kind from ten areas of Tabriz. For ensuring the validity and reliability of the study of this research, the validity and contental and questionnaire reexamination method have been used, and its reliability coefficient obtained equal to 82 percent. The data of this research have been analyzed using descriptive and inferential statistics methods and SPSS software. The data obtained from the research shows the lack of enough capital and appropriate education have caused the number of the occupied people in the informal economic section to be increased, and the migration of rural people to the city (Tabriz) has significant role in creation and development of this section of economy. The habitats of most of the people occupied in informal section of Tabriz city are in the marginal areas and poor districts of the city.