Central place theory-Human Geography
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Central Place Theory proposes that settlements form a hierarchy based on the goods and services they provide. Larger settlements can support more specialized, high-order functions and have a greater sphere of influence than smaller settlements. Christaller developed a central place model where the ideal shape for a settlement's sphere of influence is a hexagon to ensure all areas are served without gaps or overlaps. His K=3 and K=4 models show how consumers are distributed between central places based on thresholds and ranges. However, Christaller's model has limitations as it relies on assumptions rarely seen in reality, such as uniformly distributed populations and flat, isotropic landscapes.
Central place theory-Human Geography
- 1. Central Place Theory This is theory concerned with the functional importance of places
- 2. Central Place • -is a settlement that provides goods & services. It can be small (a village) or large (primate city) all settlements form a link in a hierarchy London 7m Cambridge 108,000 Norwich 122,000 Peterborough 156,000
- 3. Why are there very few large settlements?
- 4. Settlement hierarchy • Why are there very few large settlements? • Large settlements need a very large population (threshold) to support all of their functions (services) • Large settlements provide very high order functions (Great Ormond St, Houses of Parliament). Because these functions are so highly specialised there is not enough demand to support more than a few of them
- 5. Sphere of influence • Is the area around each settlement that comes under it’s economic, social & political control. Reading Luton London 7m Cambridge
- 6. Sphere of influence • The extent of the sphere of influence will depend upon the spacing size & functions of the surrounding central places Luton Reading London Cambridge Norwich
- 7. Central place functions • These are the goods & services it provides for local customers & for clients drawn from it’s wider sphere of influence Luton Reading London Cambridge Function= a service Population size does not necessarily determine the importance of the central place
- 8. Range & Threshold • The range of a good or services is the maximum distance that people are prepared to travel in order to obtain it. (short distances for a low order item e.g. newspaper) • The threshold of a good or services is the minimum number of people required to support it i.e. 2500- doctors surgery • 500-primary school/ 25,000-shoe shop 60,000 for a large supermarket/ • 100,000- large department store/ 1million University • The more specialised the service the greater the number of people needed to make it profitable. Range (km) Threshold =
- 9. Range & Threshold • Low order items (basic items)= newspaper • High order items (specialised items)= furniture • Low order functions (basic services)= corner shop/ Primary school • High order functions (specialised services)= university/ hospital • Settlements providing low order services = low order settlements (rural) • Settlements providing high order services= high order settlements (urban)
- 10. Changes in population size & number of functions • Settlement sizes change over time (via births, deaths, migration) • Settlement functions (services) change over time • Over the past 50yrs in the UK= decrease in the no’ of services available in small settlements and an increase in the no’ of services provided by larger settlements Settlement size- increases Numberoffunctions 1940 1998
- 11. Factors that affect a settlements number of functions • Settlement depopulation or increased population • Greater wealth & mobility means some rural populations no longer visit their own local services but go further afield seeking services from higher order settlements • Domestic changes (deep freezers) means rural household, no longer make use of daily low order services (village shop) Population size does not necessarily determine the importance of the central place but there is a strong correlation
- 12. The rules of functional hierarchies • 1. The larger the settlements are in size, the fewer in number they will be • 2. The larger the settlements grow in size the greater the distance between them • 3. As a settlement increases in size the range and number of it’s functions will increase • 4. As a settlement increases in size, the number of higher-order services will also increase (the services become more specialised) (service)
- 13. Walter Christaller’s model of central places • The theory states that threshold and range act as laws that govern the number, size and distribution of settlements • When these 2 factors act together they create a hierarchical landscape • Christaller noticed in the flat land of South Germany that towns of a certain size were roughly equidistant (uniformly spread) • He stated that the ideal shape for each towns sphere of influence should be a hexagon because circles either leave gaps (which are unserved by any central place) or they overlap (meaning one area is served by too many central places)
- 14. Christaller's central place theory • Christaller stated that the best shape for a sphere of influence is a hexagon. This shape means that consumers still have accessibility to the highest order central place and its trading area from all parts of the hexagon. • Christaller's key idea was that customers would go to the nearest higher order central place to buy goods and services • High order central places act like a magnet for consumers. • He called this phenomenon K=3 (or the marketing principle) • In order to make his theory work Christaller had to make a few assumptions • He assumed that each trading area had an isotropic surface (that the whole area was the same all over) i.e. the whole area was flat there was only 1 form of transport (and transport costs were proportional to distance) the population was distributed evenly across the plain
- 15. Source: http://www.uwec.edu/bfoust/155/G155_RS3/sld002.htm What's wrong with circles? What’s wrong with circles
- 16. The areas within the black dots shows the sphere of influence (trading area) of the largest settlements Like London
- 17. Example -the highlighted lower order settlement (village X) will have 1/3 of is consumers go to the city (settlement A) and 1/3 will go to town Y and 1/3 will go to town Z (middle order settlements) All the other lower order settlements (red dots) will follow the same pattern. Settlement X The high order (3rd order) settlement (A) in the middle is surrounded by medium order settlements (black dots) and lower order settlements (small red dots). These consumers are attracted in equal amounts to whichever large central place is nearby. K=3 The marketing principle Y Z Why is K=3 called K=3? Hint look at the numbers of consumers who visit the highest order settlement
- 18. K4= The Traffic Principle In the K=4 model the lower order settlements (red dots) only have a choice of 2 higher order settlements to visit, in order to buy goods and services. -Half of them go to settlement A and the other half go to a medium order settlement (black dot) How did K=4 get its name? Why is K=4 called the Traffic Principle (model)
- 19. How the K=4 Traffic principle got it’s name The K=4 model is called the traffic principle because the model shows how consumers are influenced in where they go to shop for goods and services by transport routes The Crossways train-line In this example the low order settlements (red dots) are located along a transport route. This means that these low order villages can only visit other settlements that are also on their transport route. So they are limited to visiting the settlement behind them on the transport route or the settlement in front of them.
- 20. Why is K7 called K7? U V X Y W Z A high order central place is shown. -All the low order settlements lie within the hexagonal trade area (U,V,W,X,Y) This model shows a hierarchy of control -Lower level settlements are arranged within the sphere of influence of the highest order settlement. This is done so that the lower order settlements can be completely controlled by higher levels. K=7 The Administrative Principle
- 21. The uses of Christaller’s central place model • The model is often used by governments to plan the location of new towns (i.e. Milton Keynes) and high order services i.e. hospitals • It is used by transport authorities to plan transport routes( so that all areas have equal access i.e. K4 model) • Businesses can use the model to decide where to locate a new shop
- 22. Limitations of Christaller's model • Few real-life regions fit Christaller's model (except the flat lands of the Dutch Polders and East Anglia in the UK) • The problem lies in the basic assumptions of the model: • People do not always go to the nearest central place (they may chose a new edge of city superstore further away) So the K3 theory wouldn’t work. • Large areas of flat land rarely exist. Mountains & hills etc distort transport routes (so the K4 theory wouldn’t work) • People and wealth are not evenly distributed (if poorer people live in a certain area & their nearest high order settlement is expensive then they won’t visit it) • Governments often control where new towns are located, not market forces (i.e. not necessarily where the demand for goods and services is highest) Hill Train-line