What are population phenomena? - science - 2023



The population phenomena they are events that affect the demographic status of some area, region or country. These are phenomena related to population change and usually originate from natural causes, although they also occur from human causes.

These phenomena include events related to the birth of people (reflected in the birth rate) and events involving death (such as epidemics or other events that affect the death rate). They also include events that affect the total population of a country, such as the migration and immigration rate of a locality.

Main population phenomena

Birth rate

The birth rate is a measurement that is used to determine the number of individuals born in a population in a given period of time. Usually an indicator of the number of individuals born per year is used based on every 1000 inhabitants.

This means that if 35 people are born in a population for every 1000 inhabitants, it is said that it has a birth rate of 35 individuals. In turn, this number is reflected in the age of its inhabitants.

A given population can be divided into groups according to how old each one is. On an average measure, society is subdivided into three groups:

- Young people not of reproductive age.

- Adults capable of reproducing.

- Adults not able to reproduce.

The greater the number of inhabitants who fall into the category of adults capable of reproduction, the greater the number of births tends to be in relation to every 1000 inhabitants.

Mortality rate

The mortality rate represents the number of individuals who die from any type of natural cause in a population. It is measured in the same way as the birth rate: taking the number of deaths that occur for every 1000 individuals that make up a population.

There are several ways to measure a mortality rate, as it can refer not only to deaths in general, but also to a specific type of death. For example, a fetal mortality rate can be established: a ratio between the number of infants born and those who die in the fetal state.

You can also create a demographic pattern for the number of mothers who die in childbirth relative to those who do not, or you can even determine a death rate for the number of people who die from diseases or medical conditions.


The term epidemic refers to a disproportionate increase in the occurrence of a particular disease within a specific population group. In turn, these diseases influence population movement in two ways:

- The first is through the massive increase in deaths. This occurs when the epidemic disease is fatal.

- The second is through the migration of the population. When a region is known to be susceptible to disease occurrence, those who are not infected tend to relocate temporarily or permanently.

Before turning into epidemics, diseases are usually present in a community, but generally in a reduced form. The natural level of a disease in a given society is called endemic.

When the natural level of endemic cases increases, the disease becomes an epidemic. For example, if an average of 100 people with smallpox is found in a given demographic region, the disproportionate increase in this number (to 200 or 300 cases) makes it an epidemic.

Migration and immigration

Although they are so closely related, the concepts of migration and immigration are different by nature. Migrating refers to the act of moving from one place to another. Immigrating specifically refers to the act of moving from one country to another.

The term migration is generally used to refer not to one person or family, but to a much larger group of people. In a given demographic region, the term migration is usually used when talking about a massive population movement, such as an exodus.

Migration can also refer to a move that occurs within the same country, but does not take place within the same city, but on a larger scale.

Industrial activities

Industrial activities that take place in an area can affect the growth of a region both positively and negatively.

The establishment of heavy industries that generate high environmental pollution usually deteriorates population growth and instigates emigration so that its inhabitants are not exposed to harmful components.

On the other hand, industries that provide well-paying jobs tend to attract large numbers of people to a region. This industrialization process is very effective in less populated regions, and local governments tend to favor the growth of industries for this precise reason.

Although industrial activity is not a demographic phenomenon per se, it is the catalyst for most of the large population movements related to employment today. It is an important part of human geography.

Population growth

The term population growth is used to encompass all terms that refer to the growth of a population. On a global scale, it is estimated that the total growth of the planet's population is 1.1%, which translates into almost 90 million people a year.

This growth rate takes into account the birth rate and the death rate. That is, not only is the number of people born in a year taken into account, but the number of people who die in a year is subtracted.

Population growth can be used to measure the number of individuals who are born or die at different scales. That is, it is not limited to population growth in the world, but also considers the demographic growth of a specific population.


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