The syllabus says
Natural change
- Explain the contribution of natural change to patterns of population density within urban areas.
key terms
The following key terms are taken from the Population Resource Bureau's website.
- Rate of natural increase: The rate at which a population is increasing (or decreasing) in a given year due to a surplus (or deficit) of births over deaths, expressed as a percentage of the base population.
- Birth rate (or crude birth rate): The number of births per 1,000 population in a given year.
- Death rate (or crude death rate): The number of deaths per 1,000 population in a given year.
urban growth and natural change
The rate of urban growth (the number of people living in urban areas, not urbanization which is the proportion of people living in urban areas) is increasing fastest in low and middle income countries, as seen from the selected cities below.
Source: http://www.prb.org/Publications/Lesson-Plans/HumanPopulation/Urbanization.aspx
A more visual and interactive map showing city growth from the Economist is here.
The reasons for this increase are a combination of migration and natural increase. There is very little data about the relative impact of these. However, several key points can be summarised:
- HICs generally have very low rates of natural increase, sometimes experiencing negative natural increase. Any growth in urban population is due to immigration or centripetal movements such as gentrification
- Urban natural change is usually lower than rural areas
- Urban dwellers have fewer children due to improved economic prospects, increase in prenatal, postnatal and maternal healthcare, and female emancipation being stronger in urban than rural areas
- Life expectancy in urban areas is generally higher than in rural areas but there remains a significantly lower birth rate in urban areas