Unit 3. studying population
- 1. UNIT 3. STUDYING POPULATION WHY IS IT NECESSARY TO STUDY POPULATION?
- 2. 1. POPULATION GEOGRAPHY Population geography: Studies the inhabitants of the planet and their relationship to the physical environment, analysing the evolution and composition of the population and its spatial distribution. To find out about (conocer más detalles) the population, geography uses a science: demography, which deal with the quantitative and statistical study of the population. Therefore, is the statistical study of human populations, especially with reference to size and density, distribution, and vital statistics (births, marriages, deaths, etc.).
- 3. A) USES OF DEMOGRAPHY. Since ancient times, governments have tried to monitor the number of inhabitants in their territory to find out who has to pay taxes or to make it easier to recruit soldiers. For example, in ancient Rome censors counted the population. In modern times, states have other reasons to be interested in population figures, such as planning for the cost of pensions or forecasting how many places are needed in schools and hospitals.
- 4. B) DEMOGRAPHIC SOURCES. Nowadays, developed countries count their population using questionnaires, such as census forms, which allow them to find out accurate population figures, as well as information about certain characteristics (age, sex, occupation…). However, in the poorest countries, population figures are based on estimates made by governments and by other agencies, such as United Nations, which allow them to know approximately population figures.
- 5. C) DEMOGRAPHIC SOURCES IN SPAIN THE POPULATION CENSUS: an official document published by the National Institute of Statistics (Instituto Nacional de Estadística o INE). The census takes place every 10 years, although the data are updated continually.
- 6. THE CIVIL REGISTRY: in this registry, the Ministry of Justice records all births, deaths and marriages that take place in the country. It is compulsory to register these events.
- 7. THE MUNICIPAL REGISTER: a document prepared by municipalities which includes data on age, sex, addresses, level of education and economic activity of the inhabitants of a municipality.
- 8. Population geography is used to study population from two different perspectives: DEMOGRAPHY STATIC Characteristics of population at any given time DISTRIBUTION STRUCTURE BIOLOGICAL STRUCTURE: age or sex ECONOMIC SITUATION DINAMIC Population´s evolution over time NATURAL MOVEMENTS MIGRATORY MOVEMENTS
- 9. 2. THE ESTRUCTURE OF THE POPULATION A) 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 (0-14 years old) the adult population (15-64 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.
- 10. If we want to study the biological structure of population, we can use population pyramids. There are different types of population pyramids: TRIANGLE SHAPE It reflects a very young population. High percentage of the population under 14 years old. Very small group of elderly people. Example: poor countries in Africa. BELL SHAPE It reflects a young population. The group of elderly people has increase because the age of death is higher. Example: developing countries (Brazil or Argentina). URN SHAPE It reflects an ageing population because of fewer births. Example: population of Europe (image below) or Spain and developed countries in general. POPULATION PYRAMIDS NOTE: as much EUROPE (740 millions inhabitants) as SPAIN (46.5 million inhabitants, more women than men) have an urn shape pyramid of population.
- 11. B) Economic situation. According to the economic structure, we can stabilising two main population groups: Active population: people who are available for work. Employed population: people who have a paid job. Unemployed population: people who are looking for a job. Inactive population: people who do not do paid work and are not seeking it (students ages over 16 and pensioners, for example).
- 12. 3. NATURAL MOVEMENTS THE BIRTH RATE (NATALIDAD): number of births during one year. If we want to know whether the birth rate is high or low, we have to calculate the crude birth rate according to the following formula: Note: birth rate are low in developed countries (have rates lower than 20 ‰), whereas less developed countries have rates with higher values (can be as high as 50 ‰). The crude birth rate in Europe are between 9 ‰ and 11 ‰. In Spain, 9.17 ‰.
- 13. THE DEATH RATE (MORTALIDAD). Is the number of deaths during one year. If we want to know whether the death rate of population is high or low, we have to calculate the crude death rate according to the following formula: Note: developed countries have low death rates (below 10 ‰), whereas in less developed countries these rates are high (poor sanitary conditions, hunger…). For example, in Spain the crude death rate is 8.48 ‰.
- 14. OTHER DEMOGRAPHIC INDICATORS RELATED TO MORTALITY: The infant mortality rate: In Spain 2.82 ‰ Life expectancy: 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. Besides, in less developed countries life expectancy is below 50, while in developed countries it is about 80. In Spain, life expectancy is 82.87 years.
- 15. THE RATE OF NATURAL INCREASE. To calculate the rate of natural increase over a period of time, this formula is used: There is a positive natural increase if the number of births is higher than that of deaths → population is growing. There is a negative natural increase if the number of deaths is greater than births → number of inhabitants decreases. Note: The rate of natural increase in the world is at 1.2 %, indicating that the world population is continuing to grow. However, the highest rates correspond to developing countries. In Spain, the natural increase is 0.06 %
- 16. Currently, as you can see in the chart below, it is calculated that the world population exceeds 7.3 billion. Billion= mil millones / Billón= un millón de millones