Introduction to Christaller’s Central Place Theory (CPT) – a location theory
Central place theory was given by Walter Christaller in 1933, CPT in urban geography is one of the most appreciated theory which tries to explains the spatial arrangements and distribution of human settlements and their number based on population and distance from another human settlement. This theory was first given by German geographer Walter Christaller in 1933, on the basis of his study of settlement patterns in southern Germany. This study included the analyzing the relationships between settlements of different sizes and related their economic activities (market) with the population. He explained why the highest order settlement has very peculiar activities which can only be supported by them and the reason behind the those activities taking place only in those particular highest order settlements, he also explained the nature of activities in different order of settlements. Central place theory is of great importance even after decades and forms basis of various present day theories used in urban planning.
Assumptions of Central place theory
Walter Christaller made some assumptions to make his theory easy to understand and form basis for other theories. These assumptions were necessary and holds good to explain the structure of settlements. These also take into account the growth and development of towns, human behavior and fundamentals of economics. Central place theory is based on following assumptions:
- An even (flat) terrain – A hilly and uneven terrain poses difficulty in development thus a flat area which promotes growth of town
- Evenly distributed population – residents are not concentrated at one particular place and no preference exist for a particular town
- Evenly distributed resources – no place has an advantage of resources, all placed will compete under perfect market conditions
- Similar purchasing power – along with the population and resources, wealth is also fairly distributed because of which people have similar purchasing power
- Preference for nearest market – people will buy products from the nearest market and avoid longer commute keeping the price constant as per other assumptions
- Equal transportation cost (proportional to distance) – the cost incurred in transporting of goods is equal for all and is proportional to distance
- Perfect competition – price is decided on basis of demand and supply, people will buy at lowest price which market has to offer, no seller has advantage over other seller.
These assumptions when combined results in place offering different services in which people enjoy perfect market and purchase from nearest place to save on money and time. Different services locates themselves on the basis of threshold population i.e. the minimum number of people required to sustain that service/activity. In addition to this there is no preference for a particular shop, all people have access to equal resources and does not enjoy any advantage over its competitor. The demand for goods consumed & used on daily basis will be used more and vice versa.
Two main concepts of Central Place Theory
Central Place Theory is based on 2 fundamental concepts which are “Threshold” and “Range”
Threshold – The minimum population needed to make a service viable at a particular place. If this size is not reached than a particular activity will not start or it will be required to closed down.
Range – This is the maximum distance a consumer is willing to travel to purchase good or avail a service, beyond this distance consumer will not travel as the distance traveled for good/service will outweigh the benefit.
Sizes of settlements/communities as per central place theory
Walter Christaller gave a system with 5 sizes of settlements based on population. The smallest unit is Hamlet which is considered a rural community and the largest unit is Regional Capital. The rank order of central places in ascending order include:
- Regional Capital/ Metropolis
Markets and Services tend to be nested hierarchies with smaller towns serving smaller markets. However, transportation and border effects can shift the distribution of towns away from theoretical uniformity.
Principles in arrangement of the central places:
Central place theory gives 3 principles which are the marketing principle, transport principle and administrative principle for orderly arrangements and the formation of hierarchy. Settlements are regularly spaced – equidistant spacing between same order centers, with larger centers farther apart as compared to smaller centers. Market area is hexagonal shaped as it proves to be free from overlapping most efficient in both number and function.
The different layouts predicted by Christaller have K- values which show how much the Sphere of Influence of the central places takes in — the central place itself counts as 1 and each portion of a satellite counts as its portion:
- Marketing Principle (K=3)
- Transport Principle/ Traffic Principle (K=4)
- Administrative Principle (K=7)
The three principles of central place theory are as follows
Marketing Principle (K=3): As per this the market area of a higher order occupies one-third (1/3 part) of the market area of each of the consecutive lower size place(node) which lies on its neighbor; the lower size nodes(6 in numbers and 2nd larger circles) are located at the corner of a largest hexagon around the high-order settlement. Each high-order settlement gets 1/3rd of each satellite settlement (which are 6 in total), thus K = 1 + 6×1/3 = 3.
With K=3 the transport network is not efficient even when the distance traveled is reduced. This is because of the absence of transport links (network) between the larger places (nodes).
Transport Principle (K=4): This provides for most efficient transport network. In this case, high order place half of the market area of 6 neighboring lower order places located on the edge of the hexagon formed by high order settlement. There are maximum central places possible located on the main transport routes connecting the higher order center.The transportation principle involves the minimization of the length of roads connecting central places at all hierarchy levels. In this system of nesting, the lower order centres are all located along the roads linking the higher order centres. This alignment of places along a road leads to minimization of road length. However, for each higher order centre, there are now four centres of immediate lower order,as opposed to three centres under the marketing principle.
Administrative Principle (K=7): According to K = 7 administrative principle (or political-social principle), settlements are nested according to sevens. The market areas of the smaller settlements are completely enclosed within the market area of the larger settlement. Since tributary areas cannot be split administratively, they must be allocated exclusively to a single higher-order place. Efficient administration is the control principle in this hierarchy.
Criticism & limitations of Central Place Theory
CPT is widely appreciated and used but has its own limitations. These include the assumptions which are unrealistic. The basic assumptions are flawed as it is nearly impossible to have very large flat terrain, perfect market and absence of preference for shopping places. Today’s economy is a capitalist economy but government plays an equally important role which have strong influence on the market and the location of activities. Moreover the resources are never equally distributed and some enjoy disproportionate benefits and same is true for purchasing power. Thus to make it functional as per actual scenario various modification are required in the basic theory.