Service centres and rural-urban interaction in the North West Midlands: an appraisal of measures of centrality within the lower orders of a central place system

Abstract

Service centres and rural-urban interaction in the north-west Midlands; an appraisal of measures of centrality within the lower orders of a central place system.

This thesis is concerned with a comprehensive analysis and interpretation of the functional status and pattern of distribution of service centres in a rural part of England, and with the way in which these centres interact with their hinterlands.

It commences with a review of the published work in this field, partly in order to try to introduce some order and thematic classification into the diverse range of contributions from many disciplines which have followed from Christaller's work of the 1930's, and partly in order that this study may be seen as a logical progression from earlier work. The main themes of central place study are critically examined, although in order to avoid needless repetition with other studies the emphasis is laid upon material which has appeared since 1964. Some of the ideas and problems discussed are taken up in more detail in subsequent parts of the text.

The first main section (Chs.3-6) deals with the measurement of settlement centrality, and the question of grouping settlements into a functional hierarchy. A measure of the functional complexity of towns and villages in the survey area is built up from information
gathered from a variety of published sources, and from detailed field investigation. By the use of location coefficients an index of functional status is devised, and this is used as the basis for arranging the settlements into a ranked order of size.

Retail functions are considered as but one element of a settlement's total functional composition, and in order to broaden the base of measurement, particularly for smaller centres, service functions and social facilities are also examined. In addition, the complex inter relationships of these functions, both within individual centres and across the whole range of settlements, are discussed.

Several alternative approaches to the measurement of centrality are presented and compared, but it is the method based upon each settlement's provision of retail and service facilities which forms the first part of the procedure for ranking centres into a functional hierarchy. Different ranking and clustering techniques are examined, and an iterative grouping procedure which produces a logical statement of the hierarchy, together with a measure of accuracy for each inter group boundary, is explained and implemented. This method, which is described in chapter 6, scans a list of settlements,
each of whose functional status is expressed as a single numerical score, and systematically amalgamates the most similar items into a subset. Similarity in this context is measured in terms of the Error Sum of Squares, and a hierarchy with eight distinct orders of settlements is described.

It is suggested that measures based solely upon a centre's functional provision give a very restricted, and often inaccurate, assessment of centrality. In order to avoid this, and in an attempt to illustrate a totally different facet of the involved concept of centrality, the second section is devoted to an analysis of the use characteristics of the service centres and the nature of their zones of influence. The information upon which this section is based was mostly gathered by means of a postal questionnaire survey.

An examination of the Journeys made to towns and villages for shopping and for services,forms the initial part of an investigation into the way in which these centres exert their influence over the surrounding rural areas. The frequency of such visits, and their destinations, are analysed and a nodal structure of the area is outlined. A consideration of the journeys to shop for a selected list of goods and services leads to several qualifications to the concept of the range of a good being suggested.

The delimitation of urban hinterlands by both theoretical and empirical means is discussed, and several different hinterlands are constructed and compared for the towns in the study area. The boundary of a town's hinterland is in fact a zone of transition, and there is shown to be considerable overlap between the areas of influence of adjacent towns. There are also certain areas, in the interstices in the network of urban hinterlands where no town exerts a dominant influence. Individual rural people however are dominated very strongly by a single town for the provision of goods and services. Empirical hinterlands are constructed for the main urban centres, and the internal structure of these areas is examined. It is suggested that there is considerable variation in the strength of a town's influence throughout its hinterland, with the main independent variable being distance. The decline of a town's influence with distance for a number of different measures, can be described in general terms by a negative exponential function. The precise nature of this distance-decay function, and the numerical value of the exponents, is shown to vary according to the grade of the town. In this respect two distinct regimes of influence are shown to exist for grade 1 and grade 2 centres, thus confirming the distinction between these two orders previously found on the basis of their functional provision.

Finally the irregularities of the hinterlands of the towns in the study area are discussed, and the characteristics of grade 1 and grade 2 hinterlands for a range of different goods and services are outlined. General conclusions are presented at the end of sections I and II, and the text is accompanied by fifty figures, thirty-six tables and five technical appendices.