Multiple Nuclei Model by Harris and Ullman

Harris and Ullman proposed Multiple Nuclei Model in their paper The Nature of Cities (1945) to explain the morphology of a city. They argued that the land use pattern is much more complex than the model given by Burgress, Hoyt & Davis. They observed that the land use pattern is neither in concentric zones or … Read more

The Sector Model of Urban Morphology

Homer Hoyt and M.R. Davis proposed the sector model of urban morphology in 1939. This model was based on observations from 64 cities in the USA. He modified the Concentric Zone Model by Burgess in combination with the impact of transport routes on urban morphology and came up with their own Wedge or Sector Model. … Read more

Concentric Zone Theory by E.W. Burgess

E.W. Burgess proposed the Concentric zone theory in 1925. This model is also known as ecological theory of city structure or urban morphology. The primary concern of this model was to map the urban social problem i.e. vices and crime in Chicago city. To map the vices and crimes, Burgess mapped the different zone of … Read more

R.P. Mishra’s Growth Foci Model

R.P. Mishra gave his growth foci model in response to ideas of Perroux. Growth pole theory by Perroux was widely adopted by western scholars of his time. Boudeville tried to add spatial dimension to this theory but did not take into consideration that elaborate process of trickle down. R.P. Mishra, an Indian Geographer realized that … Read more

Boudeville Growth Pole Theory

Boudeville growth pole theory provides geographic sense to growth pole. Boudeville gave specific geographic and regional character to the growth pole. Perroux’s ideas in Perroux’s Growth Pole Theory does not specify the geographic extent of the growth pole. Boudeville tried to supplement Perroux’s idea by providing geographic dimension. He wrote his ideas in his book … Read more

Growth Pole Theory by Perroux

The growth pole theory was postulated by Francois Perroux in 1955. He considered growth pole as key driver of economic activities and development in a region. Basic idea behind his theory is that the growth in a large city propels the growth in the all the areas surrounding the large city due to exchange of … Read more

Conditions for the Survival of Coral Reefs

What are Corals and Coral Reefs? Coral or coral polyps are lime secreting small marine invertebrates. Their dead bodies result in built up of coral reefs. They live in large colonies. When these corals die, their skeleton accumulate on one site. The continued accumulation and compaction of these skeletons leads to the formation of coral … Read more

Relevance of Mobility Transition Model in India

India is a large and diverse country. Most of its diversity is contributed by immigration. The Mobility Transition Model in India has great relevance. It has one of the oldest civilization in the world. India have not found any evidence of primitive men like in Africa and Europe. Therefore, it can be said that most … Read more

Mobility Transition Model by Wilbur Zelinsky

Wilbur Zelinsky propounded the mobility transition model of migration in 1971. He analyzed the migration behavior of people in correspondence with Demographic Transition Model. Previous models like Ravenstein’s Laws, Lee’s Intervening Obstacles and Stouffer’s Intervening Opportunities etc. only analyzed process of migration as a result of constant pull and push between places. Whereas, Zelinsky’s model … Read more

Demographic Transition Theory of Population Growth

Human population growth is dependent on many social, economic and political factors. Warren Thompson (1929) and Frank Notestein (1945) proposed Demographic Transition Model after studying these factors and their effect on population growth in Europe, Australia and North America. Basic Idea behind Demographic Transition Theory Basically, demographic transition model explains the trajectory of population growth … Read more