Differential urbanization, views opinions and experiences of the World

Urban areas with features such as constant change and dynamism and Social and economic situations will evaluate. The evolution and dynamics for locational circumstances in Developed and developing countries are different and developed and shaped under specific Processes and mechanisms. In the present study, using different texts, documents method and with differential urbanization model study urban development in national level and metropolitan area. The results of this study show that urban regions in their growth and development process like cities contains of urbanization, polarization reversal and counterurbanization phases. With attention to survey of differential urbanization modeling some countries with various social economic structures, this model can be used as a capable model for analysis of urban development phases in national and metropolitan scales. Also polarization reversal phase in this model is one of most important attributes of this model can be used for analysis of urban development processes especially in developing countries.