Unit 1: Studying population

1. Introduction

Population geography studies the inhabitants of the planet and their relationship to the physical environment. Therefore, it is responsible for analysing the evolution and composition of the population and its spatial distribution. To find out about the population, geography uses a science called demography, which deals with the quantitative and statistical study of the population.

One of the aims of Human Geography is to study the population. How the population is distributed through a concrete area: town, city, autonomy, country, etc,

In order to study population, geographers use different sources such as:

  • Civil Register. In this register, the Ministery of Justice records, births, deaths, marriages, etc.
  • Population Census. Elaborated by NIS (Instituto Nacional de Estadística) every 10 years. (ended in 1). The last one was carried out in 2011. Spain had 46,815,916 inhabitants in 2011.
  • Municipal Register. Dates carried out by the local administration. Each  municipal office collects the information about, age, sex, address, marital status, economic level, etc,.


What is a Thematic Map?

All the geographic information can be represented on a map. It exists different types of maps. Thematic could represent populations, a political map, administrative division, physical map, etc,. This kind of map represents different figures throughout different colours. For instance, in demography, the population, birth rates, death rates, migrations, etc,. are represented like that:


The biological structure of the population is its composition according to age and sex.

  • In terms of age, we can distinguish three groups:

    • the child population, between 0 and 14 years old;
    • the adult population, between 15 and 64 years old;
    • the elderly population, aged 65 and older.
  • According to sex, we can calculate the percentage of men and women in the total population.

How to analyse the structure of the population? The most common graph is the POPULATION PYRAMID.

A population pyramid, or age structure graph, is a simple graph that conveys the complex social narrative of a population through its shape. Demographers use these simple graphs to evaluate the extent of development for a given population – usually an individual nation – and to make predictions about the types of services that population will need e.g. schools, hospitals, homes, etc.

The Three Basic Shapes of Population Pyramids

  • Expansive or triangle-shaped

Expansive population pyramids are used to describe populations that are young and growing. They are often characterised by their typical ‘pyramid’ shape, which has a broad base and narrow top. Expansive population pyramids show a larger percentage of the population in the younger age cohorts, usually with each age cohort smaller in size than the one below it. These types of populations are typically representative of developing nations, whose populations often have high fertility rates and lower than average life expectancies. 

  • Stationary or  Bell- shaped

Stationary, or near stationary, population pyramids are used to describe populations that are not growing. They are characterised by their rectangular shape, displaying somewhat equal percentages across age cohorts that taper off toward the top. These pyramids are often characteristic of developed nations, where birth rates are low and overall quality of life is high.

  • Constrictive or Urn-shaped

Constrictive population pyramids are used to describe populations that are elderly and shrinking. Constrictive pyramids can often look like beehives and typically have an inverted shape with the graph tapering in at the bottom. Constrictive pyramids have smaller percentages of people in the younger age cohorts and are typically characteristic of countries with higher levels of social and economic development, where access to quality education and health care is available to a large portion of the population.


1- Analyse the population of the following countries: http://www.populationpyramid.net/

2- Compare the evolution of the Spanish population during the 20th century.
– What is the meaning of each pyramid?
– What has changed during the last century in Spanish population?
– What are the consequences of a Urn-shaped or constrictive pyramid?
– Should be we worried according to this figures? Justify your answer.
The world in 7b


3.1. The birth rate

The birth rate is the number of births that take place in a population during one year. To find out whether the birth rate is high or low and to compare the evolution of the population in different places, the crude birth rate is calculated. This rate relates the number of births to the total population in which they take place.

Birth rates are low in developed countries, which typically have rates lower than 20‰.
However, less developed countries have rates with higher values, which can be as high as 50‰.


The birth rate is complemented by the general fertility rate, which relates the number of births in a place to the women who live there of a certain age profile. To calculate this rate, it is considered that women of reproductive age are between 15 and 49 years old.

3.2 The death rate

The mortality rate or death rate is the number of deaths that take place in a population during one year. To know whether the death rate of a population is high or low, the crude death rate is calculated.

Developed countries have low death rates, generally below 10‰.

However, these rates are still high in less developed countries. Problems contributing to this situation, such as poor sanitary conditions and hunger, are often caused by poverty and wars.


The infant mortality rate complements the death rate and more accurately indicates the degree of development of a place. It is calculated using the formula:

Number of deaths of infants under 1-year-old in one year
                                                    ÷                                                                     x 1000
                      total number of births in one year

Less developed countries typically have a high infant mortality rate.

Another demographic indicator related to the death rate is life expectancy. This measure, which is an estimated average, expresses the number of years that a person can generally expect to live for from the moment of their birth. In general, women have a higher life expectancy than men.

This indicator is also linked to development. In less developed countries, life expectancy is frequently below 50, while in developed countries it is about 80.

The difference between birth and death rates provides us with the rate of natural increase of a population.


If the number of births is higher than that of deaths, it means the population is growing. In this case, there is a positive natural increase.

If the number of deaths is greater than births, the number of inhabitants decrease. In this case, there is a negative natural increase.

The rate of natural increase in the world is at 1.2%, indicating that the world population is continuing to grow. However, there are significant differences in this rate between countries. In general, the most developed countries have rates below 1%, while the highest rates, over 3%, corresponding to developing countries.


 The growth rate of the world population has multiplied over recent years.

The world’s population did not reach 1 billion until the early 19th century. Within another century, this amount had almost doubled, and, by the early 21st century (a further century later), the world had more than 6 billion inhabitants. Currently, it is calculated that the world population exceeds 7.3 billion.

As we have seen, the rate of natural increase of the population depends on births and deaths. Throughout time, this rate has undergone major historic variations.

The best way to see these variations is by analysing demographic regimes, which are the combination of birth and death rates over time.



This was in place until the 18th century in developed countries.

  • The birth rate is high.
  • The death rate is high due to poor food quality and hygiene and health levels.
  • Catastrophic mortalities occur: sharp increases in the death rate due to wars, famines or epidemics.
  • Population growth is low.


This took place in the 19th century and the first part of the 20th century in developed countries and continues today in the poorest countries.

  • The birth rate remains high.

The death rate is low, due to the general improvement of living conditions, especially, advances in medicine.


This has been typical of developed countries since the second half of the 20th century.

  • The birth rate drops sharply as a result of sociological and cultural changes: the massive incorporation of women into work, new family models, the development of contraceptives and family planning.
  • The death rate remains low.
  • Growth is low or very low.


This is the model towards which some developed countries are evolving and which could be more widely the case in the future.

  • The birth rate remains low, with some occasional slight spike.
  • The death rate undergoes a moderate increase due to the ageing population.
  • Population growth is negative, as deaths outnumber births.

BBC Video: Overpopulated. PROJECT

Watch the video and then prepare a report with the most relevant information obtained on there.

  1. How has been the evolution of population shown in the video since 10,000 BC?
  2. Do you think the author is concerned about the growth of World´s population?
  3. What is the population expectancy that the video says the World will reach?
  4. What is happening in countries such as Bangladesh?
  5. Do you think education is important in order to reduce the mortal rate and control the birth rate? Why?
  6. Why the developed countries have a lower birth rate than the less developed countries?
  7. How is the projection into the future according to UN data?
  8. Will be more births or less death?
  9. Say how will be the population distributed in 2100 by continents.
  10. Explain the current situation of Mozambique
  11. Make your own conclusions according to the video you have watched and the content shown on it.


Migration is the movement of people from one part of the planet to another. The departure of people from one place is called emigration, while the arrival of people is called immigration.
In 2013, over 230 million people lived outside their countries of origin.

ACTUAL INCREASE. To calculate the actual increase in population, we need to take into account net migration and the natural increase.

  • Natural increase = births − deaths
    net migration = immigrants − emigrants
    actual increase = natural increase + net migration

    The result of this calculation can be positive, if the population increases, or negative if the population decreases.

    People may be motivated to move from a territory for various reasons. Some phenomena such as hunger, wars, natural disasters or lack of prospects tend to drive out the population of a place. On the other hand, there are territories that are attractive to people because of their wealth, freedom or future prospects.

    1. ECONOMIC CAUSES Emigrants move in search of richer areas with more and better jobs. The profile of these emigrants is very diverse; they can be highly qualified professionals or have jobs that do not require specialisation.
    2. SOCIAL CAUSES These motivations are linked to economic causes. The host country or area offers more opportunities for education, health and leisure. People also emigrate fleeing insecurity or seeking reunification with their families.
    3. POLITICAL CAUSES There are people who emigrate to escape wars or political regimes in which they are persecuted for religious, ideological or ethnic reasons. If these emigrants receive legal protection in their host country they are known as political refugees.
     Migration is classified according to different criteria:
    • If we look at duration, we can distinguish between permanent and temporary migration. In permanent migration, immigrants do not return to their place of origin; temporary migration means a limited stay that can be long-term, seasonal or even just a matter of days.
    • If we look at its causes, migration can be can be forced or voluntary. Forced migration is when someone leaves their country due to political persecution, whereas migration for economic or social reasons is considered voluntary.
    • If the criterion is spatial distribution, there can be internal migration, occurring within the borders of a state, and external migration, involving a change in the country.

    5.3 Internal migration

    The most common form of internal migration is when people move from the countryside to the city. In western Europe, this internal movement intensified after the 19th century with the Industrial Revolution, which caused large numbers of people to abandon working the land. This process is called a rural exodus. In less developed countries, this is still a huge phenomenon.

    Most cases of internal migration last a long time. However, internal migration may also be seasonal, such as agricultural workers who work on seasonal campaigns.

    5.4 External migration

    5.5 The consequences of migration

    The main consequence of migration is its direct influence on changing a place’s population size. However, as well as this, there are other consequences to consider.

    Migrations cause several consequences:

    – Consequences for origin countries.

    • Loss of population.
    • Birthrate decrease due to the emigration of young people.
    • Population ageing.
    • Loss of enterprising people.
    • Initial enhancement of the economic situation when emigrants send foreign currency to their families.

    – Consequences for destination countries.

    • Population increases.
    • Birthrate increases.
    • Rejuvenation of population.
    • Cultural exchange.
    • Initial coexistence problems:
      • Failure to adapt to the new situation.
      • Difficult integration


  • One problem is the situation of illegal immigration. Receiving countries impose barriers and limitations to the free entry of immigrants, which sometimes causes immigrants to travel in an unsafe manner and risk their lives. In addition, when immigrants come to a country and live there illegally, as they are not legally recognised, they often suffer exploitation by corrupt crime gangs and business people. For example, they often earn lower wages than those of other workers or are subjected to inhumane working conditions.
  • Another problem is the difficulty of integration. Sometimes, new inhabitants are rejected by the receiving population, which fears that immigrants may take job opportunities from them or receive social benefits from the government. Finally, if the culture of immigrants is very different, they may have greater difficulties in adjusting, making it difficult for them to integrate into society.

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