Three- pronged fork. Tree-shaped network. Net pattern.
- 1. Introduction;
- Industrial Organizational Psychology: An Applied Approach.
- Grid Resource Management: Toward Virtual and Services Compliant Grid Computing.
Three types of links between places. The very shapes of these networks differ according to the strategies chosen: whether it is a matter of tapping productions, of "irrigating" whole areas with services of all kinds , of covering or watching a territory. It still remains a. The pie-graph model could be one form of the paving model: it appears to be the result of a compromise, or of competition between equals; since not everybody can live in the centre, or near the mosque, the cake is democratically cut into slices and shared.
This model however could very easily be combined with privileged directions; some slices are "more equal than others" Quebec's well-known rang line settlement and many forms of allotments rare based on the same principle — often with the same distortions.
The domination effect only appears at a further stage in other series of choremes, seemingly less "socially determined", which introduce directions and differentiations in space. In reality domination is everywhere present here too. Models depending on gravity. These are, in fact, very frequent in spatial organisation; they include: more or less continuous gradients fig.
These are regrettably too often neglected, as they are in fact the most common, and not only in the geography of climates. Successive zones in latitude are choremes of this type, although processes are more complex in the second case. They all express, sometimes in continuous gradients, but more often discontinuously in rings and strings , the effect of the pair formed by distance and friction in space from a starting point a Une, a point or even a ring and therefore a form of dependency.
Finally, if we pass from gravity to gravitation, we find orbital models, urban "loci", which are frequently to be found, often in a hierarchical order, and associated with ring models. Rupture models express phenomena which take place along frontiers, boundaries, lines showing that one is entering a different State, "interfaces" or barriers fig. These lines or plans are places of particular attraction and therefore development or repulsion coasts, boundaries, glacis, etc. Ruptures are also where refraction or inflection occur, as. Chinese hat three-dimensional representation of continuous gradient around a pole and its two-dimensional translation on a map.
Trend surface: likewise, in relation to a line.
Geographic Information Systems/Science: Spatial Analysis & Modelling
Ring model. Symmetrical strip model related to an axis. Dissymmetrical strip model related to an interface. It is difficult to ignore the process of domination in all the phenomena taking place along these lines; these are all strategies of differential land occupation, either in order to exploit "privileged" locations or to exploit differences, i.
Contact metamorphism. Specialisation of places at interface coast, frontier, etc. Base extraverted or bridgehead introverted. Projection e. Refraction e. Inflection e. Aggregation-segregation models appear to be virtually universal fig. Birds of a feather flock together, even if sometimes more out of need than by choice. It is a matter of the means at one's disposal, of type of job and place of work, but it is also a matter of culture, of solidarity, and of access to particular facilities and equipments, etc.
This is not only true of ghettos, urban sectors or ethnic minorities. Dissymmetry models are not so well known, probably because they are not of the same kind as fundamental economic models; yet they are essential togeography. First of all because the earth revolves in one direction only Moreover, and more generally, dissymmetry can be produced directly. Location should therefore always be considered in relation to dominant fluxes, whether air currents, trade or migration fluxes. But such dissymmetries are to be found everywhere.
Spatial dynamics. All these choremes have both a static and a dynamic dimension: a certain permanence as well as a certain mobility. Others, by definition, are more essentially dynamic: they express expansions or retractions in territory, conquests and losses, settlements and departures fig. They include diffusion models but they do not end there; wherever there is a settlement, a pioneer front, a number of choremes emerge, which may be expressed as simple models: disassociated spaces with projections in the shape of outposts, and a hierarchical organisation into relay stations, command posts behind the front line, and consequently a dissymmetry in action, with a "centre" somewhat out of centre, etc.
Phases of settlement — 2. Strategic position of centre of settlement. Examples of progress of conquest. Example of withdrawal process. Recessions which are not the result of coordinated strategy, but disorder retreats, are different, and analogies must rather be sought in the way a pool of water or a certain quantity of liquid retracts, or the extension of sclerosis, in which tissues are deteriorated in patches, while other parts remain intact, etc.
I was thinking, above, of conquest or withdrawal in a given society in "inert" space, in which the society deploys alone, on the fringes of ecumene pioneer fronts or abandoned areas. Similar choremes may obviously be used to describe the conquests and retreats resulting from war or competition for territory between two different communities: the frontier between Flemings and Walloons in Belgium could provide a wealth of examples.
The syntax of choremes or the linguistics of geography. I am not pretending of course that the matter has been exhausted It seems to me nevertheless that the number of. I think there is nothing surprising about this, as there must necessarily be a limited number of good solutions to problems which are after all few in number; and these solutions are codified by experience; unsuccessful, "false" solutions 14 are usually ephemeral: as they are doomed to failure, there are very few opportunities to observe them. The number of combinations of these choremes however is practically unlimited: hence the infinite variety of concrete spatial organisations.
Visible structures are as diverse as reality itself, but the structure of structures is very simple. Speech may be rich in meaning, but it is made of a limited stock of words, themselves made of very few letters. These choremes appear to be signs, which should enable us to establish a semiology of the organisation of space.
On one side they are signifiers a discernible arrangement which hide and reveal the signified, itself a face which is in fact very clear strategies of colonisation, domination, exploitation of a vantage position, etc. These signs tell us what are or what used to be the processes brought into play. They are therefore of valuable heuristic significance.
They are very far from being simple descriptive artifices or refinements, or even simplifications aimed at people of lesser intelligence; instead they reveal, and make it possible to understand, the articulations and motives of strategies and to comprehend those fully. These strategies, as we have seen, are mainly for domination: over nature and people. But this domination takes an infinite variety of forms and exerts itself in many different directions. Identifying the relevant choremes gives us information on what matters or what used to matter: I have shown this in the few examples quoted above.
Grammatical rules. It indicates that representing reality by a specific model is not at all arbitrary and cannot simply depend on the author's talent or ideology. Admittedly, as in abstraction and caricature, there is an art of modelling. This art has rules; if it is considered as a game, it also has rules: the rules of the game; perhaps we shall end up with a science; at the very least, a method.
Spatial Data Models: Spatial Analysis II (Raster Models)
It is an experimental method Models must be tried one after the other, in order to decode the palimpsest of reality. The art or the game of making models consist in trying to find, through a conscious and rational choice, through experiments governed by hypotheses, how to represent spatial organisation in the most efficient, i.
One should not summarise at random or make diagrams without guiding principles, or be content to draw a straight line where reality is vague and sinuous, and a circle where it is roughly potato-shaped: that would be mutilation, not representation. This method is both simple and very demanding.
It consists in trying to find, according to the hypotheses made about an object, by trial and error, which choremes can be combined together, and in what way. Two points at least must be made more explicit. First of all, composition does not simply amount to addition. Elementary arrangements, or choremes, influence and distort each other, so that it is sometimes difficult to recognise the signs behind the distortions; if it were not so, reality would be perfectly easy to decipher, it would be blinding in its clarity.
This indeed does happen sometimes and then the facts of domination are crudely exposed, with segregations and inequalities; usually however societies do their best to mask these, except in the euphoria of some periods of growth. Space therefore is not immediately legible, partly for this reason, but even more of course because of the complexities of strategies and of residual phenomena. As in any other experimental method, the construction of a specific model requires a dialectic solution of the contradiction between induction and deduction.
It is not enough to observe and to test the ground in a haphazard way. There must be continual feedback between a set of hypotheses and the reality under observation. This is neither pure deduction — the choice of models to test is, of course, not insignificant and must have some relationship with the object.. This is all very rudimentary, it is the very basis of research and I should hesitate to mention it here if I did not see on the one hand that monographs continue to be published without any guiding principles and on the other that only parts of a mutilated reality are analysed while only what is measurable is retained even though measurements are made with analytical models which are simple or even simplistic even when the equations are complicated.
If the method proposed is interesting, it is because of the idea of composition, not of shading nor of elements, but of choremes, i. The composition of choremes appears to consist of several stages, depending on the successive degrees of complexity involved in the extension or depth of research, and also in changes of scale.
Thus can regional models be integrated see above 1. These fundamental combinations, which are already elaborate and complex constructions, are associated with, and juxtaposed to, each other and influence each other. They are often a necessary intermediary in understanding spatial organisation, and may themselves be very significant, particularly where they express spatial division of labour.
Modeling: Using the Language of Spatial Analysis
On a worldwide scale however, they are much more numerous than choremes while their significance is often clearer, or sometimes quite as ambiguous, but they must anyway, like choremes, be interpreted through knowledge of the system: this is the whole question of relativity in relation to "cultures", civilisations or modes of production — which might then be compared to dialects, perhaps Social relativity. What choremes show, as they reveal themselves to the researcher, necessarily belongs to the present, because of the very existence of this arrangement, but it may belong entirely to the past in terms of the processes by which it has been elaborated: structures may outlive systems and new systems may have to adapt to old structures by adapting them at the same time as they make them adapt themselves ; they "make do" with them.
One must therefore be careful what meaning one attaches to these signs; they may have two different facets as far as significance is concerned: what they meant initially and what they mean now. In any event, behind each choreme, there are, or were, processes or systems in action; choremes have a social logic. The mere fact of finding a.
There are behind these models social logics which must be identified, so that one may understand what is happening or happened ealier. Only, social logic is different according to time and place, modes of production, social formations and "cultures". A spatial organisation is always "relative": the model must be "dressed" as it is relativised.
There are at least three ways of assessing the relative position of situating a model. First of all, identifying the society which is operating in, and expressing itself through, it mode of production, social formations, relations of production, cultural models, etc. Altitudinal changes or ring structures do not have the same meaning in every society; they have been, and must be, translated and interpreted, differently — these are linguistic analogies again Secondly, identifying neighbours, the environment, in brief the "position" of the choreme, which itself changes with time, as do its neighbours Being situated on the Paris- Middle Rhine axis does not have the same meaning whether Germany is an enemy or an ally And, by definition, all choremes of contact or rupture have different meanings and different contents according to the partners they connect with, or oppose to, each other.
Third, very close attention must be paid to perspective: studying a given spatial organisation may well make it a "central" one simply because it will then find itself in the limelight while the real keys to the interpretation of it may be outside. Choremes should not be mistaken for other choremes — like looking for one's keys under a lamp-post, when in fact they were dropped a few feet away but are now lying in the shadow. I shall call this the "Morvan" effect, because this is where the phenomenon appears most clearly; it could well become a classical one fig.
Research focused on Morvan tends to make it into a "centre"; it has a centre c and appears to be at once "itself, its own periphery p and its environment e ; external affairs appear to be mostly centrifugal and minimal weight is given to administrative boundaries and socio-economic limits in the environment. Even the outline of its "heart" q is different, this "heart" being the periphery of a periphery, which makes it just as unique. Being thus forced to put things into perspective serves to remind us that the analysis of spatial organisation, or the recognition of a choreme, is only a fraction of the whole: spatial arrangement tells us a great deal, but not everything.
Different systems may result in identical forms, because the number of possible forms is in fact limited — Clausewitz often insisted that military matters and commerce are alike; the same spatial arrangement may have different effects, according to which system is active. However, these arrangements, these choremes and combinations of choremes are not empty, neutral, geometric figures devoid of meaning: they express something; in any case, they express strategies in space.
They are expressed diachronically. Choremes may change in one and the same place: the Straits of Messina have been in turns a crossroads or a pole, in other words a "centre", they have acted as a barrier, or been rejected to the periphery, according to the times; a strait is not a choreme, but is is the site of particular choremes, deriving from original phenomena, which may succeed each other through opposition.
Content, as expressed by the same choreme, may change over time, for instance the content and boundaries of gravity rings, as I have shown in the case of Champagne. Some models themselves express change, mobility in space, the dynamics of areas and lines, frontiers and boundaries.
In order to represent the most efficient arrangement of central places on a homogenous plain, Christaller developed three geometric models. In these models, he arranged places relative to administrative, transportation, and marketing principles , noting that each of these functions requires different spatial arrangements in order to achieve maximum efficiency on the landscape. In the marketing principle, his organizational strategy focuses on expressing the highest distribution of goods and services from a minimum number of central places. In this model, each B-level place is located halfway between three neighboring centers of the next highest order A level.
These halfway points form the corners of hexagonal market areas of the next highest order. Each higher order place is surrounded by six places of the next lowest order. Central places at the same level are equidistant or one unit apart from one another. Each higher order place and the distance between these higher order places is the square root of three 1.
While testing his model in southern Germany, Christaller established the following hierarchy of central places:. Since then, the development of spatial models has greatly enhanced the ability of geographers to predict human spatial behavior. Skip to main content. Anselin , Review of Regional Studies 37, Housing Prices Berlin. Rose diagram directional LISAs. Visualizing Non Planar Neighbours. Also includes methods for spatial inequality and distributional dynamics.