Undoubtedly,the most important reason of urban growth is increase in urban population.
Rapid growth of urban areas is the result either of natural increase inpopulation, and/ or migration to urban areas. Natural population growth is aresult of excessive births over deaths. On the one hand, migration can bedefined as the long-term relocation of an individual, household or group to anew location outside the community of origin.
* As Britain progressed from beingjust a centre of “worldwide commerce” to embrace a “centre of manufacturingindustry”, the progress of the textile industry and the utilisation of steampower meant that employment was to be found in central locations and thus people gathered infactories. Given that Britain’s demographicexplosion in this century was at the same century that Englandexperienced the first industrial revolution, the two are tied closely together.However, studies have ruled out migration from the countryside as the main factor.
The growth didn’t occur from large numbers of foreign workers arriving butinstead it was caused by internal factors, such as changes in marriage patterns,improvements in health allowing more children to live, and an increase inbirths.PeterMathias in an attempt to find out how and why numbers rose he points out thatafter mid 18th century fertility had twice the effect of fallingmortality. The average age of people marrying for the first time fell, as didthe numbers of people never marrying, which meant more opportunity forchildren, and more children. This was partly possible because British peoplehad previously had a relatively late age of marriage compared to the continent,and a large number of people never did at all. Nuptuality, overall healthimprovements and a better diet from improved food production and higher wagesresulted in better health of mothers and the curtailment of deaths of women inthe reproductive age groups induced higher birth rates. Economical and socialconditions influenced marriage patterns. The expansion of employment inmanufacturing and trading regions offered higher real term wages, allowingpeople to comfortably start families, and as the population moved, more peoplecame into contact with each other, increasing the chances of matches, andsettling down.
*Overthe last 60 years the world experienced the most intensive expansion in urbanpopulations in many Less Developed Countries. People across rural regions ofAsia and Latin America flocked to cities where they transformed the ecology andculture of modest-sized cities, establishing bustling and sprawling urbancentres that later became beacons for rural migrants. * Over the last decadesimproved health care services, mass-immunization programs, access to cheapmedicines, and diffusion of basic knowledge about personal hygiene and sexuallytransmitted diseases led to sharp reduction in mortality. Those interventionsreduced infectious and parasitic diseases that used to thrive in denselypopulated urban settlements in the past and determined to a large amount urbanpopulation growth. *