Introduction
Central Place Theory (CPT) is an attempt to explain the spatial arrangement, size, and number of settlements. The theory was originally published in 1933 by a German geographer Walter Christaller who studied the settlement patterns in southern Germany. In the flat landscape of southern Germany Christaller noticed that towns of a certain size were roughly equidistant. By examining and defining the functions of the settlement structure and the size of the hinterland he found it possible to model the pattern of settlement locations using geometric shapes. Assumptions: Christaller made a number of assumptions such as: All areas have
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an isotropic (all flat) surface an evenly distributed population evenly distributed resources similar purchasing power of all consumers and consumers will patronize nearest market transportation costs equal in all directions and proportional to distance no excess profits (Perfect competition)
Explanation of some terms: Central Place, low order, high order, sphere of influence A Central Place is a settlement which provides one or more services for the population living around it. Simple basic services (e.g. grocery stores) are said to be of low order while specialized services (e.g. universities) are said to be of high order. Having a high order service implies there are low order services around it, but not vice versa. Settlements which provide low order services are said to be low order settlements. Settlements that provide high order services are said to be high order settlements. The sphere of influence is the area under influence of the Central Place. Details of the theory The theory consists of two basic concepts:
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threshold
-- the minimum population that is required to bring about the provision of certain good or services
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range of good or services
-- the average maximum distance people will travel to purchase goods and services
From these two concepts the lower