â  â â â â â  â  â  abstract: â  there is a significant relationship between economic growth and the degree of urban concentration, as measured by primacy or the share of the largest city in an urban system. in accordance to urban economic theories, there is an inverse-u shape relationship between urban concentration –urban primacy- and economic growth. that is, as economy grows, urban concen...

extended abstract 1. introduction today the irregular growth of the population and its illogical distribution across natural and cultural environments of different communities has necessitated sustainable development in response to the unstable conditions of cities. mashhad is a city with fast growth and development but with no clear plan, especially after land reform program. in this sense, th...

introduction according to available statistics, nearly half of the world population is living in cities and there is expectance of increasing in the coming decades. urban areas are the main centers of economic, social and political growth in every country that have prove itself as the most attractive places to build wealth, work, creativity and innovation. but these areas face with important ch...

like other developing countries, iranian cities are growing and expanding physically at a high speed. for about five decades, the only policy of the urban development plans in the field of urban growth management has been definition of the urban growth boundary (u.g.b.) which is still used without any major modifications.despite the slight evidences indicating the ineffectiveness of the current...

like other developing countries, iranian cities are growing and expanding physically at a high speed. for about five decades, the only policy of the urban development plans in the field of urban growth management has been definition of the urban growth boundary (u.g.b.) which is still used without any major modifications.despite the slight evidences indicating the ineffectiveness of the current...

All life form on this planet depends on clean air. Air quality not only affects human health but also components of environment such as water, soil, and forests, which are the vital resources for human development. Urbanization is a process of relative growth in a country’s urban population accompanied by an even faster increase in the economic, political, and cultural importance of cities rela...