Patterns of Population Growth
In this unit, we will study how humans react to both natural and man-made changes on Earth's surface. There is no greater way to study human geography than through data collection on populations. There are many different questions we could ask about a population that will explain how they and why they live their lives the way that they do.There are basic questions, like "how many people are there?", "Is there an equal amount of males and females?", and "How old are they?"
Eventually, the questions we ask about a population will become more detailed. How many schools are there? What kind of houses of worship are there? How does this specific area generate income (make money)? How old is the labor force? These questions can be answered by studying the country's population growth, or the total percentage of births and deaths over a period of one year in addition to the number of people immigrating to and emigrating from that country during the same time period.
Aside from the total size, the most important demographic characteristic of a population is its age and gender structure, or the proportion of people at each age divided between males and females. The age-gender structure determines potential for future growth of specific age groups, as well as the total population. For these reasons, the age structure has significant government policy implications. A population of young people needs a sufficient number of schools and, later, enough jobs to accommodate them. Countries with a large proportion of older people must develop retirement systems and medical facilities to serve them. Therefore, as a population ages, needs change from childcare and schools to jobs, housing, and medical care.
Eventually, the questions we ask about a population will become more detailed. How many schools are there? What kind of houses of worship are there? How does this specific area generate income (make money)? How old is the labor force? These questions can be answered by studying the country's population growth, or the total percentage of births and deaths over a period of one year in addition to the number of people immigrating to and emigrating from that country during the same time period.
Aside from the total size, the most important demographic characteristic of a population is its age and gender structure, or the proportion of people at each age divided between males and females. The age-gender structure determines potential for future growth of specific age groups, as well as the total population. For these reasons, the age structure has significant government policy implications. A population of young people needs a sufficient number of schools and, later, enough jobs to accommodate them. Countries with a large proportion of older people must develop retirement systems and medical facilities to serve them. Therefore, as a population ages, needs change from childcare and schools to jobs, housing, and medical care.
Population Pyramids
The age-gender structure of a country can be studied through population pyramids. The overall shape of the pyramid indicates the potential for future growth. The four representations of population age-gender structure provide an overall example of what a pyramid for different levels of population growth would look like -- rapid growth, slow growth, zero growth, and negative growth. The horizontal bars show the percentage (or in some cases the actual numbers) of males and females in each age group.
The age-gender structure of a country can be studied through population pyramids. The overall shape of the pyramid indicates the potential for future growth. The four representations of population age-gender structure provide an overall example of what a pyramid for different levels of population growth would look like -- rapid growth, slow growth, zero growth, and negative growth. The horizontal bars show the percentage (or in some cases the actual numbers) of males and females in each age group.
Rapid Growth
A country with a rapid growth has a population that is increasing at a very quick rate. This will usually indicate that the country has a high birth rate (a lot of babies are being born). It also means that people are not expected to live very long, because the amount of people who are getting older is much smaller. The smaller population of older age groups could also be an indicator of the country's emigration rate, the amount of people leaving a country. This is usually a result of sub-standard or non-existent health care, and has a higher chance of happening in developing or emerging nations. Countries experiencing rapid growth will have a triangle shaped population pyramid like the one on the right. |
Slow Growth
A country experiencing slow growth usually indicates that the country will be a developed nation, like the United States. The population will show a smaller number of children and larger number of adults over the age of 18. It will also show an increase in life expectancy (people are living longer), a reflection of the better quality healthcare available.Larger population numbers can also be explained by immigration rates, the number of people who come to live in the country from other places. The population pyramid will show more of a square shape, like the one on the left. |
Zero Population Growth
When a country has an equal amount of birth and death rates along with an equal amount of immigration and emigration rate, they are considered to be in a balanced population. A balanced population is referred to as zero population growth, and is usually achieved only in more developed nations. The goal of every nation is to achieve zero population growth. A population pyramid displaying zero population growth will show an almost equal percentage of age groups all across the board. |