Concepts and Techniques in Urban Analysis

'Bola Ayeni

• Publisher: Routledge
• Year: 2017
• ISBN:
  9781351600866
• Edition: 1
• Topic: Social Sciences
• Subtopic: Human Geography
• Index: Social Sciences

This book, first published in 1979, discusses the concepts, models and techniques used in urban analysis and planning. This study reviews many of the older concepts and models of urban spatial structure, laying the foundations of analysis carried out in the later parts of the book. Topics such as social area analysis, urban economic activity and spatial interaction are considered. This comprehensive study of geography and planning presents a distinctive contribution to the understanding of the nature of the city and its inherent problems.

Part One:

CONCEPTS AND METHODS IN URBAN ANALYSIS

1	THE NATURE OF CITIES

1. Introduction

Urban analysis at the level of the individual city has seen, within the past few decades, a number of theories and models purporting to explain the internal spatial structure. Generally, these models have proceeded along three lines of investigation. The first line, characterised by the classical theories of urban spatial structure, strives to explain ecological patterns of land-use organisation through three major models, namely: the concentric zone (Burgess, 1927); the sector (Hoyt, 1939); and the multiple-nuclei (Harris and Ullman, 1945). The second, on the other hand, strives to explain the determinants of the social areas existing within the city. Two principal techniques for achieving this have been through the use of social area analysis, developed by Shevky and Bell (1955), and factorial ecology (Berry and Horton, 1970). In many cases factorial ecology has not only confirmed some of the findings of social area analysis but has also identified the complexity of the urban ecological field.

The third major approach to understand urban spatial structure is based on micro-economic considerations of household behaviour. In this regard, it has been argued that the urban land-use pattern is determined by the urban land-rent mechanism, which provides the theoretically perfect site in terms of the trade-off between site rentals and the cost of overcoming the friction of distance. Micro-economic theory of urban spatial structure pioneered by Wingo (1961) and Alonso (1964) has been very valuable in terms of researches generated both on theoretical and empirical fronts as well as in the general orientation of urban research. None the less, it is generally recognised that while these models and theories are laudible, they have not succeeded in totally explaining urban spatial form.

In this chapter, therefore, we shall provide a synthesis of the major tenets of these traditional approaches and in particular attempt a critical evaluation of the assumptions and hypotheses that underlie their formulation. We believe this is the only way to examine the applicability of these ‘North American’ models to cities in other parts of the world, where there may be cross-cultural differences as well as differences in societal value systems. Furthermore, it is expected that our synthesis will generate a suitable conceptual framework for much of the development of methods and techniques in the rest of the book.

2. Classical Models of Urban Spatial Structure

(i) The Concentric Zone Model

The concentric zone model, developed by Burgess (Park et al., 1925), is really the first set of ideas towards the theoretical understanding of the city. It postulates that urban land use is arranged around a single centre, the central business district (CBD), in concentric zones made up of the zone in transition, the zone of the independent working men’s homes, the zone of better residences and the commuters’ zone (see Figure 1.2.1). The central business district is the hub of all urban activities, including financial, economic, social and recreational functions. In may also have some light manufacturing activities towards its outer fringes. The second zone comprises areas of residential deterioration as a result of the encroachment of business and industrial activities from the first zone and it is usually occupied by first-stage migrants. The third zone, the zone of independent working men’s homes, comprises largely the residences of second-generation migrants into the city, while the fourth zone contains the residences of the middle class and is occupied by managers, clerks, salesmen and professional people. The last zone, the commuter’s zone, is a ring of encircling small cities, towns and hamlets which serve as dormitory suburbs for the wealthier city-dwellers (see Figure 1.2.1).

Furthermore, it was argued that the zones are not static, as each tends to extend its area by the ecological process of ‘invasion and succession’. Although it was not explicity stated in the formulation of the model, the operation of the urban rent mechanism was implicit, as it underlies the process of invasion and succession of land uses.

The generalisations contained in this concentric zone model of urban land-use organisations were based on empirical studies on the growth of Chicago. Consequently, the model has been criticised as not being the prototype of all American cities, especially since it can be shown that not all cities grow concentrically around a single centre. None the less, the fundamental assumptions of this model remain unchallenged (Davies, 1937; Quinn, 1940; Murphy, 1966, pp. 207–10) and few of the critics of Burgess provided alternative explanations. One who did was Homer Hoyt.

(ii) The Sector Model

The second model of urban spatial structure, though developed by Homer Hoyt, had its origins in the works of Hurd (1924) who described urban expansion as ‘axial growth, pushing out from the centre along transportation lines’. However, Hoyt’s formulation was based on extensive empirical investigation of rent differentials and the ability of urban functions to bid for city lands. According to him,

rent in American cities tends to conform to a pattern of sectors rather than of concentric circles. The highest rent areas tend to be located in one or more sectors of the city . . . There is a gradation of rentals downward from these high rental areas in all directions. Intermediate rental areas . . . adjoin the high rent area in one or more sides and tend to be located in the same sectors as the high rental areas. Low rent areas occupy other entire sectors of the city from the centre to the periphery (Hoyt, 1939, p. 70).

Figure 1.2.1: The Concentric Model of Urban Structure

Figure 1.2.2a: The Sector Model of Urban Structure

Figure 1.2.2b: The Multiple-nuclei Model of Urban Structure

Consequently Hoyt’s model was meant to be an alternative to that of Burgess. The effect of land pricing leads to the occupation of the central zones by CBD functions alone as it is the only group of functions that could afford the rent. On the other hand, the major lines of transportation constitute lines of least resistance for growth in addition to their being important arteries along which similar types of land use are situated. The result is the emergence of a star-shaped pattern of city growth in which different types of land use radiate from the CBD along particular sectors towards the periphery of the city (Figure 1.2.2a).

The sector model did not go unchallenged (Firey, 1947, 1950; Rodwin, 1950), in spite of its extensive empirical background. However, in a recent appraisal by Hoyt (1966) it was maintained that residential land use in American cities still follows the sector pattern modified to a large extent by the influence of the automobile. Perhaps the one single important criticism of the sector model as well as the concentric model was the assumption of a monocentric urban area, a fact hardly borne out in any part of the world. This is probably one of the reasons why the multiple-nuclei model was proposed by Harris and Ullman.

(iii) The Multiple-nuclei Model

This model had its origins in the works of Mackenzie, a contemporary of Burgess, although it was formally set out by Harris and Ullman in 1945. It was formulated to forestall one of the criticisms of the earlier two models that visualised urban growth as originating from one single centre. According to Harris and Ullman (1965), the land use of a city is built around several discrete nuclei rather than one single nucleus as postulated by the sector and concentric models. Such a nucleus may be residential, industrial, commercial, etc., or even political as in the classical example of London, which has political and administrative centres. Of course other nuclei may arise from different requirements of urban activities as in the antagonising requirements of heavy industrial and high-class residential activities (see Figure 1.2.2b). The number of nuclei would vary greatly from city to city, although it is usual to expect this to vary with size of cities. Once a nucleus has been formed, the other types of land use are expected to develop around ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• List of Figures
• Acknowledgements
• Preface
• Introduction
• PART ONE Concepts and Methods in Urban Analysis
• PART TWO Simulation Techniques in Urban Analysis
• Index