Presentation on theme: "Central Place Theory “Models are not real, but help us understand reality”"— Presentation transcript:
Central Place Theory “Models are not real, but help us understand reality”
Central Place Theory Central Place: market center for the exchange of goods and services by people attracted from the surrounding area Theory explains how services are distributed and why a regular pattern of settlements exists German geographer Walter Christaller (1930)
Note the regularity of spacing between urban centers -- towns. Local lore has it that the distances between towns evolved because it was the distance someone could travel in a day. The Cumberland Valley of Pennsylvania is a portion of the Great Valley of the Appalachians. Broad valley floor, agricultural, settled in the early-to-mid 1700s
“If... “ Isotropic Surface – “featureless plain” with no barriers to movement Even Population Distribution – similar in purchasing power and behavior Homo Economicus – “economic man” with purely economic motives Integrity of the Law of Supply and Demand – customers needed for a business to stay open
“Then... “ There will be a regular spatial order in the number of central places of different population sizes. – Few large places – Many small places There will be a regular spatial order in the spacing of central places of different population sizes. – Large places relatively farther apart – Small places relatively closer together
Central Place Functions Categories of like services found in a central place Grocery Stores Gas Stations Jewelry Stores Book Stores Hair Stylists Auto Dealerships Houses of Worship Schools Doctors Dentists Museums Concert Halls
Would you travel farther to buy a new car or the week’s groceries? To buy a new car Would you travel farther to go to elementary school or to go to high school? Would you travel farther to see your family physician or a heart specialist? To see a heart specialist To go to high school
A Hierarchy of Educational Services Hamlet: No Schools Village: Elementary School Town: High School City: College
Stock Exchange Sports Stadium Regional Shopping Mall Major Department Store Income Tax Service Convenience Store Gas Station
How big is the trade area of a service center? It depends on... - How far a consumer is willing to travel for the service - How many customers a service needs
Each central place function has a: Threshold: the minimum number of people needed to support a central place function With fewer customers a store cannot afford to stay in business. Range: the maximum distance beyond which a person will not travel to purchase a good or service Beyond a certain distance people cannot afford the travel costs.
Optimal Location (for Pizza Shop) Fig. 12-6: 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).
Supermarket and Convenience Store Market Areas Fig. 12-8: Market area, range, and threshold for Kroger supermarkets (left) and UDF convenience stores in Dayton, Ohio. Supermarkets have much larger areas and ranges than convenience stores.
Best Location in a Linear Settlement
Rank Size Rule George Zipf – 1949 The country’s nth largest settlement is 1/n the population of the largest settlement 2 nd largest city is ½ the largest 4 th largest city is ¼ the size of the largest
Rank-Size Rule: United States CityPopulation New York City8,391,881 Los Angeles3,831,868 Chicago2,851,268 Houston2,257,926 Phoenix1,593,659 Philadelphia1,547,297 San Antonio1,373,668 San Diego1,306, 300
Rank-Size Distribution of Cities Fig. 12-9: 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 City Rule The largest settlement has more than twice as many people as the second-ranking settlement. Primate City=largest city Denmark – Copenhagen 1 million – Arhus 200,000 United Kingdom – London 8 million – Birmingham 2 million Thailand – Bangkok 1.5 million – Nonthaburi 250,000