This shows the relationship between the distance and the population density from a central point. It is the graphical technique which shows the rate of decline of population density with increasing distance from the central point of concentration.
The rate at which population density declines with increasing distance from a central is known as population density lapse rate. The relationship between population density and the distance from the central point is inverse (negative exponacial relationship). The steepness of the curve indicates the rate of decline. The steeper the gradient of the curve, the faster the decline and the more gentle the gradient? the slower the decline
a sketch diagram of population lapse rate
VARIATIONS IN POPULATION LAPSE RATE
It varies between the less developed countries and the less developed countries because of their level of socio-economic development.
DEVELOPED COUNTRIES
Their lapse rate is more gradual and illustrated by a gentle slope.this means that the densities between the cities and rural areas are not too different.
Reasons for the gentleness of the slope
Long history of urbanization leading to an even spread of population from the center to the periphery.
Decentralization : As the government discourages rapid growth with the city.
Creation of green belts and new towns to di-congest cities .Their population densities drop in cities and increase toward the peripheries.
Transport development that makes movement easy.
Urbanization problem (pollution, congestion etc).
Improvement in social welfare facilities.
People on retirement prefer to stay calm in rural areas.
DEVELOPED COUNTRIES
Here the situation is different, the lapse rate is very steep showing that population density is very high in cities and very low in rural areas . A greater concentration of population is found in the urban areas and decreases rapidly with increase in distance towards the peripheries.
REASONS FOR HIGH CONCENTRATION IN CITIES
Urbanization is rapid.
Greater economic development in urban areas .
Availabilities of social amenities.
