Concepts in Human Geography - Part 1
Fall 2012, Lecture 3
-Why is distance so important in (urban-economic) geography?
-Distance— critical determinant of real-world, spatial relationships
-The “First law of geography”: Everything is related to everything else, but near things are
more related than distant things.”
-What does this mean? Why is this the case?
Human Systems and Spatial Interaction
Spatial interaction: the movement of phenomena – people, goods, money, ideas, etc.
(What spatial interaction have you carried out today?)
-Spatial interaction is necessary, in simple terms, because not all things are available in all
So getting something that is available in place A to/from place B involves spatial interaction
therefore costs. 1. Ullmann postulated that spatial interaction is controlled by “three flow-determining
-Complementarity: the supply + demand relationship between 2 places. Ex: for
interaction to occur place A must have/supply what place B wants/demands.
-Interaction does not occur simply because places are different. Ex: Greenland and
-Supply Location (place A) must be linked to a market (place B). Ex: fruits/vegetables
grow in California shipped to urban markets in Canada.
2. Transferability: The acceptable costs of an exchange. Ex: Availabilities and demand
might not be linked due to prohibitive costs ($, time).
-How mobile a commodity is
-is determined by three interrelated conditions:
(1) the characteristics and value of the good
(2) the distance, measured in time and money, over which it must be
(3) the ability of the good to bear the costs of movement
3. Intervening Opportunity
Closer opportunities will reduce the attractiveness of interaction with more distant
alternatives. Ex: interaction is more likely with closer opportunities than with more
distant opportunities (all other things being equal).
Other considerations: 4. Distance Decay: The decrease in interaction with a location as distance from that location
increases. (fig 3.7 P.68)
Related to the concept of “the friction of distance” - the restricting effect of distance on spatial
interaction. Ex: the greater the distance the less the interaction between two locations.
5. The gravity model:
-other factors, besides distance influence interaction. Specifically larger destinations will
generate more interaction than smaller destinations.
-Newton’s ‘law of universal gravitation’ ( the attractive pull between two objects is
proportional to the