On The Delimitation of The Sub-Areas Within The Nagoya Metropolitan Area

Abstract

The aim of this paper is to discover the underlying hierarchical structure of the Nagoya Metropolitan Area, and to delimitate a group of smaller nodal regions, i.e., metropolitan sub-areas, which are included in the metropolitan area. First of all, the fringe of the metropolitan area is delimitated by means of several statistical data concerning the daily commuting movement, person's trips, origin-destination studies of road traffics, etc., which reveal the functional linkage between the metropolis Nagoya and its hinterland. This area, occupying the greater part of Nobi plain, has relatively few topographical obstacles and a fairly developed transportation network with Nagoya as its main starting point.The sub-areas are delimitated by two methods, theoretical and empirical. The procedure of the former method, based on the gravity model well known as the Leilly's law, is as follows. If in a co-ordination system, the origin is placed at the one point (place A, See fig. 5) and the other point (B) is chosen as (d, o), then the condition for equal effect in (x, y) is expressed as follows, CA/x2+y2=CB/(x-d)2+y2 which gives (x-CA·d/CA-CB)2+y2=(d√CA·CB/CA-CB)2 which means a circle with radius r=d√CA·CB/|CA-CB| and the center point m=CA·d/CA-CB. The measurement of mass (Ci) used to characterize each of the centers in this study area, where the topographical and transportational conditions are favorable for the application of the method mentioned above, is an estimate of “basic” retail annual sale and employment possessed by it. Through this method, we can delimitate five sub-areas with Ichinomiya, Handa, Seto, Tsushima, and Komaki as the centers.The delimitation of the sub-areas by means of the empirical method is based on several kinds of empirical data including daily commuting movement, medical service flow, consumer behavior, etc. These data, which show the spatial interactions between the dominant cities except for Nagoya and the smaller centers, enable us to obtain a delimitation of socio-economic areas and of administrative ones. As to the former, the study area is divided into six socioeconomic areas and five of the centers of these areas are identical with those derived through the theoretical method. As to the latter, we have twelve patterns, slightly different from one another, of administrative areas according to the difference of the data utilized for the delimitation.When we compare the theoretical sub-areas on the basis of the retail sales with the actual sub-areas based on the empirical data concerning many kinds of spatial interaction, we may say that they coincide with each other to a relatively high degree. A more detailed comparison, however, reveals a slight discrepancy between the two patterns, especially in the viciniy of the metropolis Nagoya, which is excluded expediently from the study area in order to eliminate its influence over the wider area. This discrepancy might be attributed to the fact that the index of the centrality used in the theoretical method is limited to the economic function and that the non-central function of industrial or dormitory cities in the area concerned deviates the spatial interaction performed by central functions.After all, in this study area, there are five metropolitan sub-areas with the centers situated almost at regular intervals