Areal Differentiation

areal differentiation The study of the spatial distribution of physical and human phenomena as they relate to other spatially proximate and causally linked phenomena in regions or other spatial units. Along with spatial analysis and landscape approaches, this is often seen as one of the three major  approaches to understanding in human geography . It is indeed the oldest western tradition of  geographical inquiry, tracing its beginnings to the Greeks Hecateus of Miletus and Strabo. The geographer, in Strabo\'s words, is \'the person who describes the parts of the Earth\'. But description was never simply taking inventory of the various characteristics of different regions. The purpose was to understand those features of parts of the Earth that were of greatest political and military significance. This understanding was to wax and wane in relative importance down the years. But it never completely faded away, even if revived under different circumstances and using different concepts and language. The \'classic\' epoch of regional geography, to use Paul Claval\'s (1993, p. 15) phrase, was reached in the late nineteenth and early twentieth centuries when much of the conceptual debate in geography was devoted to the concept of the region. Such geographers as Paul Vidal de la Blache and Alfred Hettner were leading exponents of regional perspectives. An influential modern statement of geography as areal differentiation, drawing from the arguments of Hettner  in particular, was made in Richard Hartshorne\'s The nature of geography (1939). This is usually seen as claiming that geography is about showing how unique regions reveal the co-variation of   phenomena that can only be understood through identifying regions. Hartshorne\'s repeated use of the term areal differentiation and his avowed indifference to the \'phenomena themselves\' could well lead to such an idiographic interpretation. The logic of the presentation, however, suggests that recognizing regions requires investigation of similarities as well as differences over  space. Areal differentiation, therefore, is about establishing degrees of sameness as well as difference between regions (Agnew, 1989). Hartshorne\'s critics (principally exponents of the spatial-analysis view of the field) accused him of seeing locations as unique and justifying a traditional regional geography in which \'areal differentiation dominated geography at the expense of areal integration\' (Haggett, 1965). This led to the association of areal differentiation with the particularity of regions at the expense of attention to more extensive geographical  patterns and to the causes of such spatial distributions. Defining geography as a spatial science thus moved the field away from a central concern with regions as spatial clusters of linked  phenomena. In the 1980s areal differentiation made something of a comeback as a central perspective for  human geography. The revival is neither directly connected to older debates such as those  between Hartshorne and his critics nor is it monolithic. Indeed, there are at least three specific intellectual positions in the revival, none of which uses the same concepts or vocabulary as the others. The first derives from the streams of thought referred to collectively as humanistic

geography. Their focus on the social construction of spaces, on place as the setting for human action, on sense of place and on the iconography of landscape has given rise to an interest in the relationship between specific geographical contexts or locales and social life in general (see, e.g., Tuan, 1977; Entrikin, 1990; Feld and Basso, 1996). The second source of revival has come from the analysis of uneven development and the geography of layers of investment often associated with the idea of a changing spatial division of labour. Rejecting the model of a geographically undifferentiated capitalism, a number of geographers have attempted to infuse into Marxist geography a concern for conjoining \'general processes\' with \'particular circumstances\' to explain spatial variations in economic activities and well-being (e.g. Massey, 1984; Smith, 1990). The third source of influence comes from attempts to create contextual theory in social science, in which the place or region is viewed as geographically mediating between human agency and social structure and is thus implicated directly in the production of society (Agnew, 1987). Versions of structuration theory and time-geography have been particularly influential in defining this strand of revival in the tradition of areal differentiation (see Giddens, 1984). The third strand could be seen as potentially integrative of the other two, in that it is at the same time concerned with both the subjective experience and the objective determinants of regions. But there are important philosophical differences between the three directions that limit the  possibility of synthesis between them. (Although, for a recent magnificent attempt at engaging with all three simultaneously, see Sack, 1997.) The first direction tends to privilege the human subjective experience of place whereas the other two view the division of space in terms of  objective socio-spatial processes with, for the third direction, sense of place arising out of the conditions created by such processes. The second and third part company over the second\'s insistence on associating general processes with the abstract and local contingencies with the concrete (Smith, 1987). The third rejects the conflation of the general with the abstract and the local with the concrete (see abstraction), preferring to see places and regions as contexts in which no single geographical scale is necessarily dominant a priori in their production. Persisting dilemmas continue to limit convergence between the elements of the revival. One is the tension between analytical and narrative modes of thought and presentation (Sayer, 1989). Another has been the general lack of attention to the multi-scalar nature of the processes  producing areal differentiation, with a given phenomenon (e.g. new jobs, unemployment, or  votes for a political party) showing a different geographical level of aggregation in different time  periods because of the shifting balance of local and extra-local influences (see scale) (Agnew, 1996; Swyngedouw, 1997). This is a particular problem for those locality studies that remain transfixed by the local. The final and most challenging dilemma remains that of how to achieve neat boundary delimitation when the territoriality of social groups is dynamic and flows of   people, goods, and investment change the character of regions and places from one era to another  (e.g. McDowell, 1997). (See also chorography.)Â (JAA)