• Defining spatial interaction
• The roles of spatial interaction
• The Uilman model
• Distance decay and gravity models
• the Break Point Model
• The Huff Model
• Expontents: Shaping the Curve
• Theissen Polygons
Definig Spatial Interaction
Involve the movement of goods, people, materials, and other tangible commodities, between the different
nodes of the city along transportation channels
• Delivery trucks or trains taking raw materials or finished products to factories or stores along
roads or railways
• Commuters going to and from work using roads or subways. Blue collar, white collar, pink collar
• Oil or sewage flowing along pipeline
• Migration of people ( and their thing and culture) from out your city or country to inside your city
Refer to the transmission of more intangible commodities such as information between nodes in the city
along sometimes less visible transmission channels.
Example: • Flow of electricity, telecommunications, and the internet either along telephone wires or through
wireless transmission mediums
• Flow of ideas that occurs within a classroom or opinions through the pages of a newspaper. As
you interact with other people, this may include diffusion of ideas or new technologies.
• Flow of money or ‘thought’ goods though the internet
• Require some type of infrastructure.
• Occur at various scales, from the individual through the neighborhood to the city, region, country
• Occur in various ways, ranging from tangible things moving along tangible channels to intangible
things moving along intangible channels. Ex, purchase online to get a ebook, teleparty.
Collectively, all of this is known as spatial interaction and should be viewed as an integral part
of both your life and that of the city, essential to growth, functioning, and survival because it is a
necessary link in the process of decision making .
reciprocalexchangelive & fake
value, attitudes, belief, culture
interaction can be better or worse
The Roles of Spatial of Interaction
• It permits integration of the various spatially separated parts of the city
• It permits differentiation and specialization within the system (comparative advantage)
• It acts to organize the system, since the magnitude and nature of the flows create and define the
hierarchical levels that exist in the system.
Organize system neskd hierarchies
• It acts as an agent of change since it provides the means by which commodities (such as new
fashions) and ideas/opinions (suchs as “we need a new government”) to move freely to all
individuals within the system The Ullman Model of Spatial Interaction
• Complementarity (a supply and demand relationship) much exist for interaction to take place.
Need , supply.
• …this will only work if there is no intervening opportunity between the points of supply and