Why Models?Why Models?

By creating models about migration, geographers can describe and predict how people will move from place to place.

These models allow governmental leaders, to plan how to allocate resources and create public policies that will affect people who migrate into or out of different places on Earth.

By creating models about migration, geographers can describe and predict how people will move from place to place.

These models allow governmental leaders, to plan how to allocate resources and create public policies that will affect people who migrate into or out of different places on Earth.

The Takeaway! The Takeaway!

Human geographers collect and analyze statistics to better understand patterns and phenomena on Earth.

Human geographers construct models to relay information about patterns and phenomena on Earth.

The gravity model of migration is one tool for understanding and predicting migration patterns

Human geographers collect and analyze statistics to better understand patterns and phenomena on Earth.

Human geographers construct models to relay information about patterns and phenomena on Earth.

The gravity model of migration is one tool for understanding and predicting migration patterns

“There must be a force pulling the apple to Earth!”

“There must be a force pulling the apple to Earth!”

Sir Isaac Newton determined that the force of gravity between any two objects in the universe depends on the mass (population) of the two objects and the distance between them.

Human geographers hypothesize that migrants are more likely to move to large cities that are not too far from their place of origin than small cities that are farther away.

Sir Isaac Newton determined that the force of gravity between any two objects in the universe depends on the mass (population) of the two objects and the distance between them.

Human geographers hypothesize that migrants are more likely to move to large cities that are not too far from their place of origin than small cities that are farther away.

One benefit of the gravity model of

migration is that it is fairly simple and can be easily used to compare

the likelihood of migration between different pairs of

locations.

Distance and population may not be the most important

determining factors.

There are many variables that the gravity model does not address

There are many variables that the gravity model does not address

Differences in:CultureEconomyPolitical situation of

each countryIndividual preferences

and values

Differences in:CultureEconomyPolitical situation of

each countryIndividual preferences

and values **One benefit of the gravity model of migration is that it is fairly simple and can be easily used to compare the likelihood of migration between different pairs of locations.

The Gravity Model

The Gravity Model

Any model that expresses interaction

between two places as a function of:

-the sizesize of the two places (population)

-the distancedistance between them

Any model that expresses interaction

between two places as a function of:

-the sizesize of the two places (population)

-the distancedistance between them

The more

people there

are, the more

immigrants that

will enter

Here’s the MATH!

Here’s the MATH!

Human geographers use a mathematical formula to predict the likelihood of migration between places. Expressed mathematically, the gravity model of migration looks like this:

(Population of Location A x Population of Location B)M (Migration)=

2 (Distance between Location A and Location B)

Human geographers use a mathematical formula to predict the likelihood of migration between places. Expressed mathematically, the gravity model of migration looks like this:

(Population of Location A x Population of Location B)M (Migration)=

2 (Distance between Location A and Location B)

The Gravity Model

“In Action”

The Gravity Model

“In Action”

Human Spatial BehaviorHuman Spatial Behavior

I. MobilityI. Mobility

a. Circulation: No relocation of residence.

• Temporary use of space

b. Migration: Leaving the home territory and finding residence in a new location

• Refugees who are forced out of their homes

a. Circulation: No relocation of residence.

• Temporary use of space

b. Migration: Leaving the home territory and finding residence in a new location

• Refugees who are forced out of their homes

II. Activity SpaceII. Activity Space

a. What effects our activity space?

1. Age

2. The means of mobility available (the ability to travel)

3. Demands in their daily activities (do you have to travel)

b. Territoriality: Emotional attachment to and defense of home ground

c. Personal space: The zone of privacy and separation from others our culture or physical circumstances require and permit.

a. What effects our activity space?

1. Age

2. The means of mobility available (the ability to travel)

3. Demands in their daily activities (do you have to travel)

b. Territoriality: Emotional attachment to and defense of home ground

c. Personal space: The zone of privacy and separation from others our culture or physical circumstances require and permit.

Activity Space: Area within which we typically move freely on our rounds of

regular daily affairs.

Age A small child’s daily

travel v. a high school student’s

daily travelAdult’s responsible for the household v.

Elderly

Which age (or stage in life) do you think is the most mobile?

**consider all factors**

Space-Time Prism

Space-Time Prism

AKA: Time-geographyThe volume of space and length of time

within which our activities must be defined.

Critical distance: The distance beyond which cost, effort, and means strongly influence our willingness to travelThink Distance Decay!

AKA: Time-geographyThe volume of space and length of time

within which our activities must be defined.

Critical distance: The distance beyond which cost, effort, and means strongly influence our willingness to travelThink Distance Decay!

IV. Information FlowsIV. Information Flows

a. Individual communication field: Determined by individual spatial patterns of communication.

• Size and shape are defined by the individual’s contacts

b. Mass communication: Transmission of information in a one way flow.

• Few transmitters, many receivers

• No spatial restrictions

• Hierarchies in the market size requirements (national v. local news)

• There must be an audience

c. Role of technology?

a. Individual communication field: Determined by individual spatial patterns of communication.

• Size and shape are defined by the individual’s contacts

b. Mass communication: Transmission of information in a one way flow.

• Few transmitters, many receivers

• No spatial restrictions

• Hierarchies in the market size requirements (national v. local news)

• There must be an audience

c. Role of technology?

V. Information & PerceptionV. Information & Perception

a.Place perception: The awareness we have (as individuals) of home and distant places and the beliefs we hold about them.

b.Directional bias: Have greater knowledge of places in some directions than in others.

a. Barriers to information

*Is Coral Gables better than Kendall? Doral or Liberty City in Overtown?

c. natural hazards: Elements, processes, or events in the environment that can cause harm to humans.

a.Place perception: The awareness we have (as individuals) of home and distant places and the beliefs we hold about them.

b.Directional bias: Have greater knowledge of places in some directions than in others.

a. Barriers to information

*Is Coral Gables better than Kendall? Doral or Liberty City in Overtown?

c. natural hazards: Elements, processes, or events in the environment that can cause harm to humans.

Natural HazardsNatural Hazards

1. Hazardous events are relatively rare

2. Residents usually resettle

3. Hazardous areas are usually coastal

4. Hazardous areas are often residentially desirable

5. With time, the memory of hazardous events fades

1. Hazardous events are relatively rare

2. Residents usually resettle

3. Hazardous areas are usually coastal

4. Hazardous areas are often residentially desirable

5. With time, the memory of hazardous events fades

Why Stay?Why Stay?

Elements, processes, or events in the environment that can cause harm to humans.

Elements, processes, or events in the environment that can cause harm to humans.

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