Why are Consumer Services Distributed in a Regular Pattern? 12.2

Central Place Theory A central place like Orlando is a market center for the exchange of goods & services by people attracted from the surrounding area. Central place theory explains how services are distributed & why regular patterns of settlement exist.

Hexagons are often used to delineate market areas…Why? The area surrounding a service from which customers are attracted is known as a market area or hinterland. In order to determine Market area you need to know RANGE and THRESHOLD. Hexagons are often used to delineate market areas…Why?

Range of a Service Range is the maximum distance people are willing to travel for a service. short distances for everyday services, long distances for other services. May be expressed as time.

Threshold is the minimum number of people needed to support a service. The median threshold needed to support this Kroger grocery store in Dayton, Ohio is about 30,000 people.

Demographics Things to consider Age Gender Marital status Children Disabilities Mobility Race Home ownership Income Employment status Family size Religion Ethnicity Education Occupation

Remember it is all about maximizing profits!!! SOOOOOOO… LOCATION, LOCATION, LOCATION

Gravity Model T The gravity model predicts that the optimal location of a service is directly related to the number of people in the area and inversely related to the distance people must travel to access it. GIS can help companies determine where to locate a new facility using the gravity model

Best Location in a Linear Settlement The optimal location for a pizza delivery shop with seven potential customers in a linear settlement (top) and with 99 families in apartment buildings (bottom)… the median location is always the best.

Christaller’s Central Place Theory Market areas are arranged into a regular pattern according to central place theory, with larger settlements fewer and further apart.

Rank-Size Distribution of Settlements Rank-size rule states that the 2nd largest city is ½ the size of the largest…the 4th largest city is 1/4th the size of the largest and so on… Cities in the U.S. closely follow the rank-size distribution, as indicated by the almost straight line on this log scale. In Romania, there are few settlements in two size ranges.

Primate Cities The primate city rule states that the largest settlement has more than twice as many people than the 2nd largest settlement. Paris is an example of a Primate City because it has over 11 million people. The 2nd largest French city, Lyon, has less than 2 million. Found in more LDCs