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Geography Chapter 3
Spatial Interaction and Spatial Behavior
- Spatial interaction - the movement of goods, people, and ideas within and between areas. Resources and human efforts are not uniformly distributed.
- Interaction flows are shaped by flow-determining factors:
- Complementarity Factors - compare supply at one point with demand elsewhere. (core/periphery relationships)
- Transferability Factors - compare cost of movement to the value gained. (expression of commodity mobility)
- Inter-related conditions:
- Characteristics/value of product
- Movement distance (time, money, other factors)
- Ability of commodity to bear cost of movement
- Intervening Opportunity - closer alternatives that reduce the attractiveness of longer-distance interactions.
- Friction of distance - distance has a retarding effect on interaction due to increasing penalties in time and cost.
- Gravity Model (a model of spatial interaction) - The attractive force existing between areas is related to the force of gravity.
- Distance is often calculated as travel time or cost.
- Suggests that the size of interacting places as well as the distance between them is important in predicting spatial exchanges.
- Law of Retail Gravitation - explains how large cities have greater drawing power than smaller ones.
- Where you shop, according to this model depends upon where you are in relationship between the 2 cities.
- Are the goods available at a larger city worth the cost of travel?
- Interaction Potential - since the world is more than just 2 places (we are usually offered more than 2 opportunities in choice making) all places within a region act upon each other.
- Potential model - tells the relative position of each point in relation to all other points - maps the intensity of spatial interaction.
- Patterns of spatial interaction, once established, tend to affect the conditions under which future interactions will occur.
- These patterns result in:
- Movement bias - determines the regularity of flow.
- Distance bias - short distance over long.
- Direction bias - actual flows are restricted to a few directions.
- Network bias - A network is a set of routes and the places they connect. The presence or absence of connecting channels (roads, bus routes, air routes, etc.) strongly affects the likelihood of spatial interaction.
- Human Spatial Behavior
- Mobility vs.Migration
- Mobility - all types of human territorial movement. Temporary uses of space that requires no relocation of residence.
- Migration - Permanently leave a territory (a place).
- Individual Activity Space
- Territoriality - emotional attachment and defense of a home ground.
- Activity Space - area in which a person operates. The extent of activity differs in accordance with that person's age, sex, wealth, employment, etc. Daily activities are both space and time consuming.
- Space-time Prism - the volume of space and length of time within which activities must be confined.
Women's prisms tend to be more restrictive than men's.
- Critical Distance - distance where cost, effort and means strongly influence willingness to travel.
- Information flows are a form of spatial interaction - space is different regarding information.
Type of Information Flows:
- Personal communication - person-to-person (informal, unstructured transmission of information).
- Mass communication - source-to-area (formal, structured transmission of information).
- Mental maps summarize a person's acquired information and perceptions.
- Near places are better known and preferred to distant ones.
- Direction Bias - created by barriers to information flow, reflecting greater information flow in one direction regardless of the distance involved.
- Perceptions of favorable climatic and other attractions and considerations of recognized natural hazards may also influence mental maps and bias.
- Perception of Natural Hazards
- Low-level hazards don't create negative space perceptions.
- High-hazard areas - often posses desirable topographic characteristics (beaches, view, hillslopes, etc.).
- Perception of natural hazard is a luxury - the poor don't have the option to relocate from areas with high levels of natural hazards.
- Migration - permanent relocation of a residential place.
Migration has contributed to the evolution of human culture.
3% of world population live in a country other than that of birth.
- Principal Migration Patterns:
- Intercontinental - historical spread of human activity and culture.
- Intracontinental-Interregional - reflects a flight from dangerous environmental, political, economic or political conditions.
- Rural-to-Urban - increasing as poor farmers move to cities to look for jobs or escape unrest. This movement puts pressure on urban resources and infrastructure - more so in developing countries than developed.
- Types of Migration:
- Forced migration - 12 million Africans brought to Western hemisphere as slaves.
- Reluctant migration - international refugees or government colonization plans.
- Voluntary migration - the majority of human migration.
- Motivation for Migration:
- Poverty - 30% of world population make less than $1/day.
- Environmental refugees abandon land that can no longer support them.
- Controls on Migration:
- Place Perceptions are basic to decisions to migrate. Those decisions at any of several scales from intercontinental to local are affected by:
- "pull factors" (positive) of perceived improvement in personal condition
- "push factors" (negative) considerations of escape from home area dissatisfactions
- Place Utility - the value placed on potential residential locations.
- The decision to migrate is colored by personal factors of age, sex, career stage, and so forth.
- The move may be reluctant rather than voluntary and therefore under different control mechanisms.
- Incentives to migrate may be counterbalanced by migration barriers.
- Resistance to or rejection of legal and illegal migrants by destination countries restricts free international movement.
- Other Migration Terms:
- Step Migration - movement from rural to urban environment in small steps:
Rural → Small town → Small city → Large city → Urban
- Chain Migration - established migrant flow where advance group of migrants provides links to others.
- Counter Migration - return migration - 25% of migrants return to their place of origin.
- Migration field - the area from which a place draws migrants.
- Channelized Migration - tendency for migration to flow between areas linked economically, historically, culturally, etc.
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