2.2 The effects of population growth and change on the lives of

Social sciences: geography

Grade 7

Population growth and changes

Module 6

The factors that influence growth and change

1. Definitions (to ensure that we all understand exactly what we read)

• The word demography refers to a statistic description of the population (the number of people living in a specific area). The word is of Greek origin, in which demos refers to the people , and graphy to description .

Demographers don’t guess – they calculate! They use scientific knowledge to predict the possible effects and outcomes of population density.

Demography is an important field of study, as future planning often depends on whether the population is on the increase or on the decrease. To make a sound decision about e.g. where a dam is to be built, and when, the planners should seriously consider the population growth – the rate at which the population is either shrinking or growing. The planning of a new dam cannot wait until a particular area actually experiences a water shortage!

Similarly these planners might establish that a dam is not a good idea, for instance where the population is either decreasing, or remains constant.

Some of the important studies undertaken by demographers include determining the population of a country (or area) in relation to the future availability of resources such as water and the production of food and raw materials for industries (which also means work opportunities for the inhabitants). Demographic information is therefore an essential tool for planning the future.

Populations are subject to all kinds of changes that occur in the course of time. If the population consists mainly of young people, it is referred to as a young population. But a population could also “age”. When populations experience changes, usually from “young” to “old”, we speak of demographic change.

• Statistics refers to the science or method of collecting data on mass phenomena (such as population, the country’s exports, etc.), and expressing it in numbers or figures.

• The life expectancy of human beings refers to the average age that any particular person is likely to reach according to calculations. A baby born into a community with ample resources and good health care, has a higher life expectancy than that of a baby born in a poor country where health care hardly exists. The big difference in the number of older women as opposed to older men in any South African community, shows that women in South Africa (and in the rest of the world) enjoy a longer life expectancy than men.
• Population could refer to the total number of inhabitants of any country, or that of only a small group, a city, an area, province or district. Groups (populations) can change in various ways, and change is in fact an ongoing process.
• Urbanisation refers to the process where people move to cities and towns (as opposed to those remaining in rural areas where they live in a scattered fashion).
• The use of a population pyramid is an easy way of depicting the population of any given area. The horizontal lines indicate the percentage of the population in the various age groups – divided into the two gender groups. The different age groups are stacked on top of each other. This makes it possible to obtain a very accurate total picture or image of the population at a glance.