Central place theory
The system of central places is a theory of spatial planning, locations according to the role they play as a central location ( main town ) for the surrounding area, divides into different importance classes.
History and content of the theory
The theory of a system of central places was developed in the 1930s by the German geographer Walter Christaller ( 1893-1969 ). In his model in ideal-typical, homogeneous spaces developed a structure of central places at different hierarchical levels. The central places of higher hierarchy level (for example, larger cities) in this case have features that the central locations of lower hierarchical level are missing ( for example, certain administrative and service functions in small towns ). A central place so that has a surplus of meaning for the surrounding area complement him. Christaller particular the centrality or the surplus of meaning of a place as the ratio between the services that are provided in total ( for the place and its complementary region ) and the services that are needed only for the residents of the central place itself. The difference between the two values is called a surplus of meaning. The higher the centrality of a place, the greater the number of services per occupant.
The system according to Christaller
The design of the system of central places developed Christaller first time in his major work, the 1933 published book The central places in southern Germany. He explained that a region of centers is supplied with high-order services and goods. In the original of Christaller after the supply principle (K = 3) detailed structural ten hierarchy levels were distinguished (from " alternative central place " to " kingdom of capital "). Christaller tested his theory in practice using the number and distribution of the then existing telephone lines:
Christaller put it deductively determined assumptions:
- Extensive homogeneity of spaces or sub-spaces: Production and demand are largely the same in an unlimited area
- Production factors and the population are distributed approximately evenly throughout the room
- Income, purchasing power and needs of all individuals are equal
- Approximately uniform transport links in all directions
- Transport costs are directly proportional to the distance
- Providers strive for maximum profit
- Demanders seek maximum benefit ( "homo oeconomicus " ) to
- The same information base ( omniscient ) among all market participants
- No geographical specialization of providers
- Inner Range: Under a revenue threshold of market-related threshold is understood, below which a place can not deliver a commodity, and therefore demand and sales volumes are too low to achieve an adequate profit. This threshold represents a lower limit on the supply side
- Outer Range: Under the range of a central material, the upper limit of its market area is understood. It corresponds to the distance beyond which the central place, the product can no longer sell ( consumers are not prepared to go to even longer distances ). This threshold effect on the demand side.
For the market of supply and demand works, the inner range must be smaller than the outer.
Under the theoretical assumption that the transport links in all directions are equally good, upper and lower range are circular demarcated by the central place in the geometric center.
Should have, since the outer reaches of neighboring locations are on the one hand do not overlap (part of the supplement areas would otherwise yes twice supplied ) and the central places on the other hand with one another uniform and very low distances from each other ( unserved areas may not occur ), there is an arrangement of central places supply in a regular triangular mesh with hexagonal supplement areas at any place, because the only way that an area can be completely and economically rational manner possible.
Supply and market principle (K- 3 system )
Under these idealized conditions Christaller first developed a graduated system of care centers in regions according to the market principle. Market principle: k = 3, because 1 ( 6 × 1/3) = 3 The surrounding six smaller centers sit here at the corners of a hexagon and cover one-third of their need for higher-quality goods or services in the three surrounding higher centers.
The offer of central goods is as close as possible to the places to be supplied ( triangular mesh ). A central place of higher order powers itself and two neighboring towns of lower order (hence k = 3).
In the spatial order of the Federal Republic of Germany, this structure was transferred to the planning system and whole communities are classified in a hierarchical and functionally structured, normative order model, eg in the form of sub-centers, resources centers and regional centers. They have ascending catchment areas ( supply or spheres of influence or supplement areas), increasing supply of goods and services and an increasingly dense infrastructure facilities:
- Sub-centers ( basic or small centers) serve to meet the " basic needs " (especially the short-term or daily necessities ), DAILY
- Resource Centres are intended to cover the " primary care " and the medium-term or " upscale " needs, PERIODIC
- Regional centers to cover their " primary care ", the long-term, ie "upper " and the " specialized, higher ' needs. episodic
Largely unclear, however, remains central to local facilities which are to be assigned to which central place equipment features of the respective supply or demand level. Also, it remains unclear is at what equipment density ensures or jeopardizes a minimum pension. The definition generally valid, binding equipment catalogs and standards for the minimum supply of a center is so far failed. To a limited extent can the actual importance of a center derived empirically on the retail centrality. About the other aspects of centrality (eg for centrality of transport, cultural, educational and service institutions) makes this centrality index to no direct conclusions.
An upper center, with middle and low services and goods also middle and lower center, middle center and sub center. But shrinks the catchment area according to the demand. The high-quality goods and services are in demand but less accordingly.
An example could be assigned to a primary school every sub- center. The catchment area of the primary school is locally ( close range as supply or interconnection area). A school that is less often demand corresponds to the central functions of a local middle center and normally has a correspondingly larger catchment area ( central area with several sub- centers). A university corresponds to the central place functions of a regional center, is even less frequent demand as a high school and has an even larger catchment area (upper area as supply or interconnection area or complementary region ), which ranges ideally on the territory of several lower and middle centers.
But that is not this example matches the real demand behavior shown by the fact that the people do not choose their university with a university rule, according to the system of central places, but for other, typically personal selection criteria. Even with other centrally local institutions can be said that the real demand behavior does not match the system of central places. For this reason, the system of central places in the space sciences and in the field of spatial planning law is increasingly being called into question.
Because of the ambiguities in the assignment of mandatory features are the spatial planning law, which introduced a system of central places was fixed in the spatial plans of countries and regions, often remained undetermined. Since the Spatial Planning Act for binding targets of spatial planning, however, a certainty and determinacy (standard clarity ) for the planning communities ( addressees ) requires ( § 3 para 1 No. 2 Spatial Planning Act ), reached the relevant regulations only the legally binding nature of a principle of spatial planning ( § 3 Section 1 No. 3 spatial Planning Act ) supported by the municipality as part of its bauleitplanerischen consideration (planning discretion) can be overcome.
Transport principle ( K-4 ) system
The need for the most economical transport links - as an alternative structure approach - is optimized in the K -4 system. Here are the smaller villages on the sides of the imaginary hexagons. Thus, they can be connected to the larger centers in a straight line (see figure above ). This saves money and time in road when driving.
The catchment area here corresponds to each half of the six lower centers ⇒ 6/2 1 = 4
Management principle (K- 7 system )
In the management there is a need to define clear responsibilities. The K -3 and K -4 system are here useless as smaller places would need to be divided or more higher levels (eg districts ) would belong. Here, then an assignment of the surrounding villages to a center with the K- 7 system is realized. The lower places are entirely contained in a hexagon, is located in the center of the high-order central place ( see figure above ).
Here, the scope is extended to six surrounding complete low centers and their own low center ⇒ 6 1 = 7
The concept of central places is also found in the German Spatial Planning Act (ROG ) input, which in the principles of spatial planning, among other things, the spatial concentration of settlement activity on a system of reliable central places in the context of a decentralized settlement structure calls ( § 2 para 2 No. 2 ROG ). Countries fill the framework law with the preparation of the country's development programs and land development plans from with which they identify their space according to this basic design, develop and promote.
In many cases, countries have in the design of their system of reliable central locations (eg, urban, middle and upper ranges) provided a classification of their communities in the upper, middle and lower centers with appropriate supply or interconnection areas, the different minimum standards of care should fulfill and equipment. The low density, sharpness and liability statement of the rules adopted for that purpose, however, have frequently affected the implementation of the system performance of central areas of spatial planning in the development planning of the municipalities.
The current residential development away due to new developments ( suburbanization, teleworking, just-in -time production, government funding of freight transport, mobility, lifestyles and consumption habits of consumers, etc. ) more and more of the model-like ideas Christaller's. The system of central places in spatial planning, therefore, is increasingly losing the application reference and thus important. The empirical testing of the equipment from places with central goods is becoming increasingly difficult.
As an example of the growing disconnect between the provider locations of cities corresponding level in which the major furniture retailers are mentioned (for example, IKEA ). Furniture as goods with an episodic demand must not be necessarily offered in a large city or a big city, but are often the proverbial " green field ". The priority of the provider has clearly moved in favor of accessibility for the customer and the supplier Transport: large, well -developed commercial sites are preferably close to a highway. Empirical studies have shown that furniture customer sites take up to a car traveling time of approximately one hour in purchasing.
An illustrative example of the problem of the system of central places is also the Ruhr. Its development processes and settlement structures can not be explained with the model of Christaller's because the ideal type of room and the typical market conditions, which presupposes Christaller as basic assumptions for the application of his theory, have not existed here. It is known that industrialization in the Ruhr, a process that was essential parts designed to use natural resources industry as well as to create necessary industrial plant and infrastructures that shaped settlement and structures centers of the Ruhr area specific. The acting in such a process, market forces and site conditions Christaller has not been explored and explained.
The application of a conventional system of central places in the regional planning at municipal and centers structures as they shape the Ruhr as an agglomeration, a significant problem, because that is not originally designed for atypical spaces system of central places constantly with the acting in atypical spaces Market and site conditions into conflict. In addition, the system of central places due to low density, sharpness and statement of liability developed for this purpose spatial planning legislation of the countries often can not reach through the development planning of the municipalities.