Understanding Spatial Interaction and Human Migration

1. Chapter 3 Spatial Interaction & Spatial Behavior

2. Spatial interaction & behavior • common characteristics of spatial behavior that affect and unify all people and social systems • “ground rules” of spatial interaction • physical and behavioral constraints

3. Spatial interaction • the movement of peoples, ideas, and commodities within and between areas

4. Commodity flows • points of supply to locals of demand • factors in the structure of trade: • 1. awareness of supplies or markets • 2. presence or absence of transportation connections • 3. costs of movements • 4. ability to pay for things wanted & needed

5. 3 Controlling principles Edward Ullman ((1912-1976) • 1. Complementarity • for two places to interact one must have a supply of an item for which there is an effectivedemand in the other • by desire to purchase • purchasing power • means to transport it • Or exchange – developing countries

6. International crude oil & complementarity

7. Controlling principles • 2. Transferability • Spatial interaction can only occur when there are acceptable costs of an exchange: time & cost • Characteristics & value of product • Distance measured in time & $$$ penalties • Commodity must be able to bear the costs of movement • Dynamic – relationships can & do change

8. Controlling principles • 3. Intervening opportunity • Serves to reduce supply/demand interactions that otherwise might develop between distant complementary areas • Dynamic – reflecting changeable structure of apparent opportunity

9. Intervening opportunity

10. Measuring interaction • General principles/patterns • Friction of distance • Distance has retarding effect/ time & cost penalties • Distance decay • Near destinations have disproportionate pull over more distant locations • Varies with activity • Linear distance • Only one aspect of transferability • `

11. Shape of distance decay

12. Gravity Model (Henry Carey 1793-1879) • Observations based on Newton’s law of universal gravitation: • 1. Interaction between urban centers can be calculated by size & distance • 2. Large cities have greater drawing power for individuals than do small ones

13. leading to Reilly’s law • Breaking Point: • Two cities will attract trade from intermediate locales in direct proportion to their size and distance

14. Human spatial behavior • Mobility describes all types of human territorial movement • 2 types: • 1. Circulation • a) daily or temporal • b) longer periods, such as vacations • 2. Migration • Permanent move, relocation

15. Circulation

16. Individual areas of activity • 1. Territoriality • Emotional attachment to, and the defense of home ground • 2. Personal space • The zone of privacy/separation from other our culture or our physical circumstances require or permit

17. Activity space • Extended home range • Variables: • Stage of life • Mobility • Opportunities

18. Space & time • Daily activities consume time & space Space-Time Prism Space-Time Path

19. Critical distance • Short trips are more frequent • Distance decay

20. Information age • Time & space are different for information flows due to modern telecommunications • Time & space convergence = the obliteration of space • Changing constraints, determinations on human activities, lifestyles

21. Migration – permanent relocation • Unmistakable, recurring, near-universal theme • Complementarity, transferability, intervening opportunity, barriers, all play a role • Often occurs in a series of steps, or chain, like links

22. Decision factors • Cultural, socio/economic • Distance • Responses to poverty, population growth, environmental deterioration, war, famine • Micro – macro moves

23. Distance of migration • Intercontinental • 16th to 17th centuries, very little • 19th to 20th, huge movements • Involve movements between countries or counties • Intracontinental • International • Interregional

24. Rural to urban migration • Due to Industrial Revolution • 18th to 19th centuries in U.S. & Europe • 20th centuries, worldwide phonomenon • Today more prevalent than international moves • More difficult to move internationally

25. Types of migration • 1. Forced migration • Historic & recent, 10-12 million West Africans • Caribbean, Central, South, & North America • British convicts to Australia, after 1780

26. Forced migration

27. Types of migration • 2. Reluctant relocation • 1969, 8 million Indonesians moved by government to less densely populated islands • 2000, 14 million international war refugees • Both internal or external movements

28. Types of migration • 3. Voluntary migration - largest • Push of: • Poverty, overcrowding, war, famine, environmental degradation, loss of job • Pull of: • Perceived economic opportunity, safety, food, better climate, cleaner/safer environment, family

29. Voluntary migration

30. Additional effects • 1. “Brain drain” • 2. Guest workers • 3. Time - contract

31. Counter migration • Always occurs – some migrants return to place of origin • U.S., from 1900 – 1980, out of 80 million migrants, 10 million returned to their motherland

32. Voluntary migration observations E.G. Ravenstein (1834-1913) • 1. Most migrants go only a short distance • 2. Longer distance migration favors large cities • 3. Most migration proceeds step by step

33. 4. Most migration is rural to urban • 5. Each migration flow produces a counter-flow • 6. Most migrants are adults; family moves are less likely to be international • 7. Most international migrants are young males

34. Migration patterns

35. Characteristics today • Most migrants are young males, not a cross section of ages • U.S. – peaks in late 20’s • West Africa – ages 15 to 39 • New trend: young females increasingly migrate • Domestic service jobs • “Entertainment” industry

36. Find your deep migration history • http://www.dnaancestryproject.com/