POPULATION DYNAMICS

WHY POPULATION SIZE CHANGES

THE SIZE OF A POPULATION DEPENDS ON A BALANCE BETWEEN SEVERAL THINGS

Birth rates Death rates

Immigration

Emigration

Population change, is the difference in the size of a population between the end and the beginning of a given time period (usually one year).

CRUDE BIRTH RATES: The number of live births per 1000 people in a population. Expressed /1000 or as a percentage. 21/1000 or 2.1%

CRUDE DEATH RATES:The number of deaths per 1000 people in a population. Expressed /1000 or as a percentage.

natural population change (sometimes “natural increase”) is the number of live births minus the number of deaths.

http://epp.eurostat.ec.europa.eu/statistics_explained/index.php/Glossary:Population_change

ACTUAL INCREASE (or “actual population change”) takes NET MIGRATION into account when calculating the changes in the population size of an area.

Migration refers to the number of migrants, people changing their residence to or from a given area (usually a country) during a given time period (usually one year).

http://www.movingpeoplechangingplaces.org/uploads/images/migration_peoplemap_smaller.jpg

Immigrants are people arriving or returning from abroad to take up residence in a country for a certain period, having previously been resident elsewhere Immigration

net migration ;the number of immigrants minus the number of emigrants

Emigrants are people leaving the country where they usually reside and effectively taking up residence in another country Emigration

http://www.jaha.org/edu/discovery_center/push-pull/img/Ellis01.jpg

http://www.irishtimes.com/blogs/generationemigration/files/2013/02/departuregates.jpg

http://epp.eurostat.ec.europa.eu/statistics_explained/index.php/Glossary:Population_change

POPULATION

Birth Rates Immigration

Death Rates Emigration

MIGRATIONNATURAL CHANGE

Birth rate and immigration increase the size of the population

Death rate and emigration decrease the size of the population

Both the CBR and CDR can be examined more closely by looking at other indicators such as:

Total Fertility Rate: (TFR) - the total number of children a woman would bear during her lifetime.

General Fertility Rate: (GFR) the number of births per 1000 women aged 15-49 years.

Infant Mortality Rate: The number of deaths of children less that 1 year old per 1000 live births.

Child Mortality Rate: the number of deaths in children under the age of 5 per 1000 children.

Life Expectancy:The average number of years a person can be expected to live.

http://dontgiveupworld.com/wp-content/uploads/2013/05/Quote-on-life-and-death.jpg

http://bashapedia.pbworks.com

/f/birth_rate.gif

http://upload.wikimedia.org/wikipedia/commons/d/d7/Death_rate_world_map.PNG

Death rateCompare and contrast* these two maps. Write your observations in your notebook.

* What is the same, what is different?

The demographic transition model attempts to explain the change in countries from having high birth and death rates to low birth and death rates.

The model is based on the change in crude birth rate (CBR) and crude death rate (CDR) over time.

In developed countries this transition began in the eighteenth century and continues today. Less developed countries began the transition later and are still in the earlier stages of the model.

http://geography.about.com/od/culturalgeography/a/demotransition.htm

DEMOGRAPHIC TRANSITION MODEL