A brief introduction to the theory and principle of central place

Cristal's theory of creating central place is deeply influenced by Du Neng and Weber's location theory, so his theory is also based on "ideal surface". Its basic feature is that every point has the same opportunity to accept a central place, and the relative accessibility of one point to any other point is only proportional to the distance, regardless of the direction, and there is a unified traffic surface. Later, he introduced the hypothesis of neoclassical economics, that is, both producers and consumers belong to the concept of people with reasonable economic behavior. This concept means that in order to maximize profits, producers seek to master as large a market area as possible and make the distance between producers as large as possible; In order to reduce travel expenses as much as possible, consumers consciously go to the nearest center to buy goods or get services. Both producers and consumers have complete knowledge of the above behaviors. The supplement of the hypothesis of economic man is very important to the formation of the hexagonal network diagram of the central place

Christopher also put forward the following concepts:

(l) A central place can be expressed as a place that provides various commodities and services to residents living in its surrounding areas (especially rural areas).

Central hierarchy

1. The center mainly provides trade, finance, handicrafts, administration, culture and spiritual services. The goods and services provided by the center are different. According to the service scope of central commodities, it can be divided into high-level central commodities and low-level central commodities. Advanced center goods refer to the center goods with larger upper and lower limits of service scope. Such as high-end consumer goods, brand-name clothing, gems and so on. And the low-level central commodities are the central commodities with smaller upper and lower limits of commodity services, such as small department stores, non-staple foods, vegetables and so on.

The central function of providing high-level center goods is high-level center function, and vice versa. For example, the specialty stores of brand-name clothes and jewelry stores that operate precious stones are high-level central functions, while the retail stores that operate small department stores are low-level central functions.

A center with a functional layout of an advanced center is an advanced center, and vice versa. Low-level centers are characterized by a large number, wide distribution, small service scope, low-grade goods and services, and few types. High-level centers are characterized by a small number, a wide range of services and a wide variety of goods and services. There are also some intermediate centers between them, and the range of goods and services they provide is between them. Residents' daily necessities can basically be met in low-level centers, but if they want to buy high-level goods or services, they must go to intermediate or high-level centers to meet them. The distribution order and spatial structure of central places with different scales and grades are the central topics in the theoretical research of central places.

2. Features

(1) The grade of the central place is determined by the grade of the goods and services provided by the central place.

⑵ The grade of the center determines the number, distribution and service scope of the center.

⑶ The number and distribution of central places are inversely proportional to the level of central places, and the service scope of central places is directly proportional to the level.

(4) A central place at a certain level not only provides goods and services at the corresponding level, but also provides all goods and services below that level.

5] The hierarchical nature of the central place is that each high-level central place is attached with several intermediate central places and more low-level central places to form a central place system.

(2) Central goods and services refer to goods produced and services provided in central places respectively, which can also be called central place functions. Center goods and services are graded, that is, they are divided into higher (lower) grade center goods produced in the center or higher (lower) grade services provided.

In most centers, each center commodity or service is usually undertaken by more than one enterprise or institution. For example, in a market town, there are usually two or three grocery stores or restaurants. Each unit that undertakes a central function is called a functional unit. To be sure, the number of functional units in the center must be greater than or equal to the number of functional categories in the center, and usually the number of the former always exceeds the number of the latter.

In addition to several units providing one kind of central goods or services, there may also be cases where one unit provides many kinds of central goods or services, so it includes several functional units. This situation is more common in large retail commercial organizations such as department stores and supermarkets.

(3) Centrality or "centrality". The centrality of a place can be understood as the sum of the relative meanings of a place to its surrounding areas. Simply put, it is the size of the central function played by the central place. It is generally believed that the centrality of a town cannot be measured by its population size, because most towns are multifunctional, and the population size is a comprehensive reflection of its position in the region. Christopher took the number of telephone gates in towns as the main index to measure centrality, because telephones were widely used at that time, and the number of telephone gates could basically reflect the role of towns.

(4) scope of service. Christopher believes that every commodity and service provided by the center has its variable service scope. The upper limit of the scope is the farthest distance that a consumer is willing to go to a central location to obtain goods or services, beyond which he may go to another central location nearby. Taking the farthest distance r as the radius, a circular complementary region can be obtained, which represents the largest hinterland of the central place. The lower limit of the service scope is the shortest distance from the hinterland needed to maintain the function of the center. Considering the radius, we can also get a circular complementary region, which represents the minimum hinterland necessary to maintain the existence of a certain level of central place, also known as the threshold distance of demand, that is, the minimum necessary sales distance.

There are three relationships between the upper and lower limits of the service scope, which are of great significance for further analysis: ① If the threshold distance is greater than the maximum sales distance of the commodity, the commodity cannot be provided normally in this area. (2) If the maximum selling distance of goods is equal to the threshold distance, then the business of such goods can be profitable. (3) If the maximum selling distance of commodities is greater than the threshold distance, not only commodities can be provided, but also operators can obtain excess profits by serving the population living between the two hinterland areas. Based on the above conditions, Christalle deduced the settlement distribution model on the ideal surface. Because Christalle is concerned about the characteristics of the settlement system developed on the basis of the evolution of rural market service centers, he also puts forward two restrictive factors that constitute the market principle: first, the number of supply points at all levels must be minimized to maximize the profits of businessmen; Second, all kinds of goods or services should be provided to all people in a region. In order to meet the first condition, the maximum sales distance of goods must be adopted in the generalization of the model, because it can minimize the number of supply points. Therefore, as a first step, Christalle assumes that a series of B-level centers are evenly distributed on the ideal surface, and the maximum sales distance of its top-level goods is set to r, so that the distance between B-level centers is 2r. If all B-levels are connected in the middle, you can get an equilateral triangular network.

However, such a system will not satisfy the second limiting factor. Because the B-class market areas are all round, consumers living in the empty corner formed by the tangency of three circles will not be supplied. Therefore, some modifications must be made to the above figure, that is, overlapping all circular market areas. After overlapping, the B-level centers are still arranged in an equilateral triangle network, but the interval is more compact, and the distance is D. In addition, the circular market area is replaced by the hexagonal market area because of dividing the overlapping area. The reason is that consumers should choose the nearest center to obtain goods or services according to the assumption of "shopping in the nearest center".

At this time, people discussed a kind of goods supply situation. In fact, a central location can provide a variety of goods. Because Christalle adopts the concept of the maximum sales distance of the top-grade goods in the B-class center, it means that the B-class center also provides a series of lower-grade goods or services. These goods and services form a continuous and decreasing hierarchical sequence. From high to low, their maximum sales distances are r- 1, r-2 and R-3 respectively. However, because their maximum sales distance is less than r, they can't serve all the places in the B-class central market area. With the decline of commodity grade, the gap between the scope of lower-level commodity market area and the scope of B-level central market area will become larger and larger. In this case, the emergence of a lower-level center, which Christalle calls the K-level center, is logical, and it can serve the residents in places where the lower-level goods in the B-level center cannot serve. The position of the K-level center is in the center of the equilateral triangle formed by the three B-level centers, that is, the position of the center of gravity, so it can compete with the B-level center most effectively. The boundary of the K-level central market area is determined by the maximum sales distance e of the top-level goods it provides.

Similar to the process of K-level central position generation, the central position of the corresponding level of A-level and M-level can be generated at the maximum sales distance of A-level lower-level goods. As an inverse process, there may be a G-level central place higher than the B-level central place, and the position of the lower-level central place is always at the center of the equilateral triangle formed by the three higher-level central places, thus forming a central place network named K=3 by Christalle. Christopher believes that there are three conditions or principles that govern the formation of the central system, namely, the market principle, the traffic principle and the administrative principle. Under the control of different principles, the central network presents different structures, and the hierarchical order of the central area and the market area is strictly regulated, that is, it is arranged in a regular and strict sequence according to the so-called K value.

1. Market principle

As mentioned above, Christalle first paid attention to the settlement system developed on the basis of the rural market center, so he first discussed the central place model established according to the market principle. According to the market principle, the center of the next level should be located in the center of the equilateral triangle formed by the three centers of the previous level, which is most conducive to the competition between the center of the next level and the center of the previous level, thus forming a system with K=3.

The number of lower-level market areas is always three times that of higher-level market areas. Because each central place contains all the functions of the lower-level central place, that is, the first-level central place is also the second-level or even lower-level central place, in the three secondary market areas to which the first-level central place belongs, it is only necessary to add two secondary central places on the original basis to meet the needs of the three secondary market areas. Nine tertiary market areas, because there is one primary center and two secondary centers, only six tertiary centers have been added. In this way, in the system with K=3, the order appearing in different scale centers is listed as:

1,2,6, 18,…

The traffic system of the central place hierarchy formed by the market principle is centered on the high-grade central place, with six radial main roads connecting the central place at the next level and six radial secondary roads connecting the central place at the next level. This transportation system is considered inefficient because the road connecting two higher-level centers does not pass through the lower-level centers.

2. Traffic principles

Christopher realized that the early road system had a far-reaching influence on the formation of the settlement system, which led to the distribution of B-level centers not on the idealized surface in an initial and random way, but along the traffic line. In this case, it is impossible for the distribution of secondary centers to achieve the maximum competitive effect among the three higher-level centers, as in the system with K=3, but in the middle of the main road connecting the two higher-level centers.

Compared with the system with K=3, the direction of the hexagonal network under the traffic principle has changed. The boundary of the high-level market area still passes through six secondary centers, but the secondary center is located at the midpoint of the boundary of the high-level center market area, so its hinterland is divided into two parts, belonging to the hinterland of two higher-level centers. For a higher-level center, it includes half of the market areas of six sub-centers except the complete market area of one sub-center, that is, it includes four sub-market areas, thus forming a system with K=4. In this system, the rank order of the number of market areas is:

1,4, 16,64,…

The number of secondary markets has quadrupled. Similar to the system with K=3, the ranking order of the number of central bits in the system with K=4 is:

1, 3, 12, 48,…

The traffic network formed according to the traffic principle is considered to be the most efficient, because the sub-center is located on the main road connecting the higher centers, and the central system formed by the traffic principle is considered to be the most likely to appear in the real society.

3. Management principles

In the systems with K=3 and K=4, except for one sub-district which is under the jurisdiction of the high-level center itself, all other sub-districts are fragmented and obviously inconvenient to manage. For this reason, Christalle proposed a K=7 system organized according to management principles. In the system with K=7, the size of hexagon is enlarged, so that the surrounding six sub-centers are completely under the jurisdiction of the senior center. In this way, the administrative subordination boundary of the central land system coincides with the supply relationship boundary.

According to the central quota system formed in accordance with the administrative principle, there are 1 senior central quota for every seven junior central quotas, and the central quota at any level is seven times that at the higher level (except the highest level), namely:

1,6,42,294,…

The ranking order of market regions is:

l，7，49，343，…

In the system with K=7, because its transportation system shows that the average distance each customer needs to travel to buy central goods or enjoy services is longer than the other two systems, the transportation system under the administrative principle is considered to be the least efficient.

Three principles and applicable conditions

Among these three principles, the market principle is the foundation, the traffic principle and the administrative principle can be regarded as the revision of the central place system formed on the basis of the market principle, and krebs further analyzed the application scope of the three principles.

The market principle is applicable to the supply of goods in central places composed of markets and market regions, such as the period of free competition in capitalism. The traffic principle is applicable to newly developed areas, traffic transit areas or areas with linear distribution of residential areas. In areas with high cultural level, large industrial population and high population density, the traffic principle plays a greater role than the market principle. The administrative principle is applicable not only to the era when the ruling institutions are strong, but also to the social life based on administrative organizations during the socialist transition period. In addition, in remote mountainous areas with strong self-sufficiency, separation from cities and relative closure, the role of administrative principles is also relatively strong.

In addition, Shashevsky also believes that high-level centers have great requirements for long-distance transportation. Therefore, the layout of the high-level center is based on the traffic principle, the intermediate center plays a greater role according to the administrative principle, and the layout of the low-level center is more reasonable to explain with the market principle.

The above three principles led to the formation of urban hierarchy. Christalle believes that in open and accessible areas, the principle of market economy may be the main principle; In the mountainous basin area, it is more important to be isolated from the outside world objectively. In young countries and newly developed areas, traffic lines are "pioneering" work for immigrants, and traffic principles are dominant. Christalle concluded that a region or country should form the following urban hierarchy system under the joint action of three principles: 1 A-level city, 2 B-level cities, 6- 12 C-level cities, 42-54 D-level cities and 18 E-level cities.