Central Place Theory Another Land Use Model Ch 12

The Father of the CPT Christaller made a number of assumptions such as: All areas have an isotropic (all flat) surface. An evenly distributed population Evenly distributed resources Similar purchasing power of all consumers

Walter Christaller developed the Central Place theory to explain the size and spacing of cities that specialize in selling goods and services. The theory consists of two basic concepts: 1) threshold -- the minimum market needed to bring a firm or city selling goods and services into existence and to keep it in business 2) range -- the average maximum distance people will travel to purchase goods and services Normally, the threshold is found within the range, as the diagram shows.

QUESTION TO PONDER… Can you think of examples from the past in Europe and from the United States today in which the range is larger than the threshold yet businesses thrive and market towns temporarily come alive?

Answer itinerant merchants in medieval Europe who would sell their wares in a different town each day or two to "collect" sufficient "ranges" to meet or, hopefully, exceed their "threshold" (market) to keep their business going in the US, multi-million dollar businesses have insufficient thresholds because the range for their products are too small; hence, professional athletic teams and popular entertainers with their high income demands travel throughout the country collecting "ranges." Already in the 19th century, catalog companies, like Sears, were already "annihilating" space, as does the internet now.

CPT To cover the whole service area and not leave an area un- served, the range circles must overlap. But consumers can only shop in one place in this theory! What is the spatial solution?

CPT Answer: hexagons (six-sided shapes) that completely cover an area without overlap or not serving any areas.

Transportation Principles The market principle predicts evenly spaced cities; but the transportation principles modify these regularities. With the transportation principle, towns that are not on major transportation routes are smaller than expected from the market principle. Transportation routes, such as a railroad in this illustration, attract business and allow new and larger towns to develop along the railroad. Rivers, canals, and highways, especially interstate highways, also reflect the transportation principle.

Political principle Political boundaries also "distort" the even spacing of cities. Why is the city on the Nevada side of the Nevada-Utah border larger? Answer: the Nevada city on state border is larger because all of the gambling business from Utah, where all types of gambling are illegal, can only be met in Nevada, where casino gambling is legal, and gamblers want to drive the shortest distance to gamble, which is the border city in Nevada, not the interior city as would be expected. You can see this pattern along Interstate 80 at the Utah-Nevada border.

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.

Conclusions That Can be Made About Central Places The larger the settlements, the fewer their number The larger a settlement, the farther away a similar size settlement is The Range increases as the population increases The larger the settlement, the higher the order of its services. Deviations to this rule are: –Tourist resorts that have a small population but large number of functions. –Dormitory towns that have a large population but a small number of functions.