Population Geography

Population GeographyPopulation GeographyPopulation GeographyPopulation Geography is the study of spatial variationsspatial variationsspatial variationsspatial variations in distribution, density, composition, and

growth of human numbers on earth.

It is important because it links all other aspects of geography together.

Demography

DemographyDemographyDemographyDemography is the study of population characteristics.

It is significant because:

1. There are more people living todaytodaytodaytoday than any other time in history.

2. There’s been a population explosion since World War IIWorld War IIWorld War IIWorld War II.

3. There is an inverse relationshipinverse relationshipinverse relationshipinverse relationship between population growthpopulation growthpopulation growthpopulation growth and resourcesresourcesresourcesresources, i.e., there are too

many people in places without enough resources to support them and too few people in areas

with over abundant resources.

Thomas Malthus

Thomas MalthusThomas MalthusThomas MalthusThomas Malthus, was a British clergyman/economist.

He came up with the Malthusian Theory of Population Growth. The salient points of his theory were

1. FoodFoodFoodFood production increased at an arithmetic ratioarithmetic ratioarithmetic ratioarithmetic ratio (1, 2, 3…) while populationpopulationpopulationpopulation increased at an

exponential exponential exponential exponential ratio (1, 2, 4, 8, …).

2. Population growthPopulation growthPopulation growthPopulation growth would outstrip foodfoodfoodfood supply, and mass starvationstarvationstarvationstarvation would follow.

3. Man is incapable of controlling his own numbers, so natural calamitiesnatural calamitiesnatural calamitiesnatural calamities such as floods and

epidemics serve to control/reducecontrol/reducecontrol/reducecontrol/reduce his numbers.

His theory was wrong in a number of ways:

1. He failed to foresee the agrarian revolutionagrarian revolutionagrarian revolutionagrarian revolution that would greatly increase food production.

2. Man has proven he is capable of controlling his numbers, such as in China China China China with the one-child

per family policy.

3. The population has not grown as rapidly as he predicted.

Components of Population Change

Components of population change are birthsbirthsbirthsbirths and deathsdeathsdeathsdeaths, immigrantsimmigrantsimmigrantsimmigrants and emigrantsemigrantsemigrantsemigrants. P (people) + B

(births) – D(deaths) + I(immigrants) – E(emigrants) = population.

Fertility and Mortality

FertilityFertilityFertilityFertility is the number of live birthslive birthslive birthslive births in a defined population. It is calculated using two main indices:

• Crude Birth RateCrude Birth RateCrude Birth RateCrude Birth Rate (CBR): (The total number of live births/the total population) × 100

• Total Fertility RateTotal Fertility RateTotal Fertility RateTotal Fertility Rate (TFR): (The total number of live births/women of childbearing age (15-49))

× 100

MortalityMortalityMortalityMortality is the number of deaths deaths deaths deaths in a defined population. It is calculated using two main indices:

Population Geography

• Crude Death RateCrude Death RateCrude Death RateCrude Death Rate (CDR): (The total number of deaths/the total population) × 100

• Infant Mortality RateInfant Mortality RateInfant Mortality RateInfant Mortality Rate (IMR): (The number of infant deaths/the number of live births) × 100

Factors Affecting Fertility

1. ReligionReligionReligionReligion: most major religions favor family developmentfamily developmentfamily developmentfamily development so very religious populations usually

have a high fertility.

2. Social customscustomscustomscustoms and taboostaboostaboostaboos, with regards to contraceptioncontraceptioncontraceptioncontraception

3. EducationEducationEducationEducation: There is an inverse relationshipinverse relationshipinverse relationshipinverse relationship between education education education education level and the number of

childrenchildrenchildrenchildren.

Factors Affecting Mortality

1. Endogenetic Endogenetic Endogenetic Endogenetic processes: These refer to internal/bodily factors, such as diseasediseasediseasedisease.

2. Exogenetic Exogenetic Exogenetic Exogenetic processes: These refer to external factors such as environmentenvironmentenvironmentenvironment.

Other indices to gauge components of population change are:

• Life ExpectancLife ExpectancLife ExpectancLife Expectancy:y:y:y: This is the number of years a child can expect to live under current

conditions. It is also the average length of lifeaverage length of lifeaverage length of lifeaverage length of life of a defined population.

• The Natural IncreaseThe Natural IncreaseThe Natural IncreaseThe Natural Increase: It is calculated by the formula (CBR – CDR/ Total Population) × 100

Migration

MigratioMigratioMigratioMigrationnnn is the movementmovementmovementmovement of people.

It is classified by such indices as:

• Distance Distance Distance Distance traveled

• ReasonReasonReasonReason fort ravel

• Period of timetimetimetime of travel

• VolumeVolumeVolumeVolume of migrants

Consequences of migration include:

• Increased understandingunderstandingunderstandingunderstanding between people of different cultures

• Increased animosity animosity animosity animosity between people of different cultures

• Changes in numbersnumbersnumbersnumbers of people at the destination and origin

• Creation of ghettoesghettoesghettoesghettoes in urbanurbanurbanurban areas

• InterInterInterInter----marriagesmarriagesmarriagesmarriages

Ravenstein’s Laws of Migration

RavensteinRavensteinRavensteinRavenstein came up with his “laws” of migration in the 1880’s based on studies carried out in the

United Kingdom.

The laws are as follows:

1. The greatest body of migrants travel shortshortshortshort distances.

Population Geography

2. This produces currents directed toward great commercialcommercialcommercialcommercial centers.

3. Each current has a compensating countercountercountercounter----currentcurrentcurrentcurrent in the opposite direction.

4. Both currents display similar characteristics.

5. Long-distance movements are directed towards greater commercial centers.

6. People in urban areas migrate lessurban areas migrate lessurban areas migrate lessurban areas migrate less than people in rural areas.

7. MalesMalesMalesMales migrate more over longlonglonglong distances and femalesfemalesfemalesfemales migrate more over shortshortshortshort distances.

Additions to these laws:

8. Most migrantsmigrantsmigrantsmigrants are between 20202020----34343434 years of age.

9. People mainly move for economiceconomiceconomiceconomic reasons.

10. Urban housing developmentUrban housing developmentUrban housing developmentUrban housing development is inadequateinadequateinadequateinadequate for the influx of migrants so ghettoes/shanties are

formed.

Zipf’s Inverse Distance Law

The volumevolumevolumevolume of migrants decreasesdecreasesdecreasesdecreases with distancedistancedistancedistance from the origin.

Stouffer’s Law of Intervening Distances

The number of migrants moving from one town (a) to another (b) is directly related to the opportunities

available at (b) but inversely proportional to the number of intervening opportunitiesintervening opportunitiesintervening opportunitiesintervening opportunities between (a) and

(b).

Push-Pull Theory

Any migration is a result of push forces at the originpush forces at the originpush forces at the originpush forces at the origin and pull forces at the destinationpull forces at the destinationpull forces at the destinationpull forces at the destination. Examples of

push forces are famine, war, and poverty. Examples of pull forces are availability of food, peace, and

wealth.

Gravity Model

This theory states that larger towns are more attractivelarger towns are more attractivelarger towns are more attractivelarger towns are more attractive to immigrants than smaller towns.

Consequences of Migration

These can be subdivided into three categories:

1.1.1.1. Demographic Consequences:Demographic Consequences:Demographic Consequences:Demographic Consequences:

• The numbersnumbersnumbersnumbers and distributiondistributiondistributiondistribution of people within a region are changed.

• IntermarriagesIntermarriagesIntermarriagesIntermarriages are created, leading to a new group of people.

2.2.2.2. Social Consequences:Social Consequences:Social Consequences:Social Consequences:

• Migration brings different people together leading to conflictconflictconflictconflict.

Population Geography

• Migration can also create understandingunderstandingunderstandingunderstanding between different groups.

• Rural-urban migration creates ghettoesghettoesghettoesghettoes in cities.

3.3.3.3. Economic Consequences:Economic Consequences:Economic Consequences:Economic Consequences:

• This depends on the “quality”“quality”“quality”“quality” of the migrants and the economic needs of the origin and

destination. Quality refers to skills, age, educational attainment, health, etc.

• In overpopulatedoverpopulatedoverpopulatedoverpopulated areas, emigrationemigrationemigrationemigration is beneficial because it reduces the pressure on the

land.

• In underdevelopedunderdevelopedunderdevelopedunderdeveloped areas, emigration may slow down developmentdevelopmentdevelopmentdevelopment.

Sex Structure

The sex structuresex structuresex structuresex structure refers to the proportions of the 2 sexes in a defined population.

It is expressed as the number of malesmalesmalesmales to every 100100100100 femalesfemalesfemalesfemales.

Male Male Male Male births usually exceedexceedexceedexceed female births, but males diediediedie off more quickly in infancy, so by the time

children are one year old, there are more females than males.

The sex structure may be affected by the following:

• Where women are considered subordinatesubordinatesubordinatesubordinate beings, they suffer a higher mortalityhigher mortalityhigher mortalityhigher mortality rate and a

lower lower lower lower life expectancylife expectancylife expectancylife expectancy.

• MigrationMigrationMigrationMigration. There is usually a dominance of malesmalesmalesmales in populations dominated by immigrants.

• In difficult environmentsdifficult environmentsdifficult environmentsdifficult environments there is usually an imbalance in favor of malesmalesmalesmales.

• Select populations, Select populations, Select populations, Select populations, such as military towns, may have an imbalanceimbalanceimbalanceimbalance for either of the sexes.

• UrbanUrbanUrbanUrban areas in developingdevelopingdevelopingdeveloping regions have more malesmalesmalesmales.

Age Structure

There are three basic age structures:

1. ProgressiveProgressiveProgressiveProgressive (Brazilian) Type

2. Stationary Stationary Stationary Stationary (American) Type

3. Regressive Regressive Regressive Regressive (European) Type

Progressive Type

It has a wide basewide basewide basewide base that quickly narrows upward to a point.

It indicates a large birth ratelarge birth ratelarge birth ratelarge birth rate¸ but poor poor poor poor conditions mean people rapidly die rapidly die rapidly die rapidly die off, hence the triangular

shape of the structure. The population is increasingincreasingincreasingincreasing.

Stationary Type

The shape of this structure is more “square.”“square.”“square.”“square.” All age groups are well represented.

Population Geography

It indicates that the birth ratebirth ratebirth ratebirth rate is moderatemoderatemoderatemoderate, and few people die off as they get older. The population is

stagnantstagnantstagnantstagnant.

Regressive Type

The structure has a fairly wide topwide topwide topwide top with a bulging middlebulging middlebulging middlebulging middle and narrow base.

The birth rate is lowbirth rate is lowbirth rate is lowbirth rate is low, hence the low base, and there are more adults than children. The population is

decreasingdecreasingdecreasingdecreasing.

The Dependency Ratio

This is the ratio between the nonnonnonnon----working populationworking populationworking populationworking population (children and aged) and the workersworkersworkersworkers (adults).

It is lowestlowestlowestlowest in regressionregressionregressionregression populations and highest highest highest highest in progressiveprogressiveprogressiveprogressive populations.

It is calculated using the formula (children + aged)/adults) × 100

In developed countries, the DRs range from 50-70. In most developing countries the DRs are over 100.

The Old Age Index

This is the proportionproportionproportionproportion of agedagedagedaged to adultsadultsadultsadults.

It is calculated using the formula ((aged)/(adults)) × 100

Theories of Population Change

These are theories to explain the patterns of population growth in different countries of the world.

1. Biological TheoryBiological TheoryBiological TheoryBiological Theory: : : : This theory states that man is like any other living thing. He is incapableincapableincapableincapable of

controlling his growthcontrolling his growthcontrolling his growthcontrolling his growth in numbers.

2. Cultural TheoryCultural TheoryCultural TheoryCultural Theory: This theory states that man is rationalrationalrationalrational and uses his intellectintellectintellectintellect to control his

growth in numbers; the one-child policy in ChiChiChiChinananana.

3. Economic TheoryEconomic TheoryEconomic TheoryEconomic Theory: Based on MarxistMarxistMarxistMarxist----LeninistLeninistLeninistLeninist theories, it supposes that growthgrowthgrowthgrowth in population

is a result of a demand for labordemand for labordemand for labordemand for labor.