宮城県における商業地システムの変容

Abstract

Hierarchy is one of the important concepts to analyse the regional structure. The author (Ishizawa, 1984a) defined “the retail central place system” as the hierarchy of the regional urban system organized by consumers' spatial movement, and explained it using the method of dyadic factor analysis. The previous study clarified that there are two types of retail central place systems. One is organized by four levels of trade areas (trade areas at basic, town, city and regional level), and the other is organized by three levels of trade areas, lacking the trade areas at the city level in the hierarchy. The previous study made the assumption that the number of hierarchical levels in the retail central place system is not determined by the size of trade activity or the trade area at the regional level center, but is determined by the competition of the trade areas at each level. The purpose of the present paper is to verify this assumption and to examine the cause of the competition of trade areas. The Trade Areas Survey in Miyagi Prefecture executed in 1978 and in 1981 are used in this analysis. The results are summarized as follows: 1. Trade areas are divided into four levels in the hierarchy. These are trade areas of a regional level, high goods (city) level, low goods (town) level, and a basic goods (village) level, which only appears in particular cases. These are the same results as reported in 1984. 2. Motorization is diffused uniformly in Japan; this means that the consumers can visit many shopping centers easily, which promotes competition between the trade areas, especially at the high goods level. With the passing years, fewer high-goods centers are left at a high level in the hierarchy, and their former rival cities fall toward the lower level of the hierarchy. So, there remain few trade areas of high goods level consisting of numerous trade areas of low goods level. Thus the hierarchy of the trade areas is made more simple over time. 3. If competition in two regions (systems) is contained within each region, the intermediate trade center functions will become weak. The cities and towns will all fall to an equal low rank in the hierarchy with the regional center at the top. The four-level retail central place system thus becomes a three-level one (fig. 5; type A→B). If competition is strong between two regions, one regional center will become sub-ordinate to the other, but will retain its own dominance over other cities and towns. Thus, the retail central place system will again change into a four-level system (fig. 5; type D). 4. If a big store, whose head shop is in Tokyo, Osaka or Nagoya, is built in the local town, it will stop these tendencies. The town or city will retain its intermediate retail functions (fig. 5; type C).