Fearing to attribute too much importance to the mechanistic and simplistic determinism of the physical environment, improperly linked with ‘determinism’, some geographers avoid using such expressions as ‘difficult environments’ or ‘unattractive (off-putting) environments’. Through this categorical attitude, we may be failing to note the introduction of an important factor of spatial differentiation. The use of the notion of ‘development costs’ by human societies seems to open the way for an efficient analysis of complex relationships. Any society, in order to ensure its survival in a given space, will be led to make some efforts, initiate some actions, which involve material costs. The term should be taken in its broadest meaning: costs that can be estimated in monetary terms, of course, but also in terms of quantity of work, of expenses undertaken for the education of workers in order to improve work quality. It is even possible to define a ‘cost’ for the organisation required to implement the necessary collective efforts. These costs may be established in relation to the obtained results, which can be characterised as ‘benefits’, as long as the term is given a broad meaning, equivalent to the one given to ‘cost’. The environments faced by actions of human groups ‘require’ more or less effort, higher or lower costs.
Naturally the notion is only relative, depending in particular on the level of available techniques.
Settling in some environments involves particularly high costs, and merely remaining there will involve considerable expense in the form of work. This has consequences for the modes of settling that are found there, as for example in arid, warm, or cold regions, where access to water is only possible by means of techniques that presuppose considerable ingenuity and labour, often imposing limits on modes of organisation. Settlement in these areas is generally sparse, undertaken on a small scale, and involving populations that assume such efforts because they face strong constraints linked to their history and/or their motivations. Hence they present particularities which are everywhere apparent, though diverse.
The desire to find ‘in the desert’ a shelter against persecutions-heterodox believers from all types of religions are over-represented in many regions of this kind, from southern Algeria to the Great Salt Lake Basin; the need to create population nodes with some cultivated land along main commercial roads, such as the trans-Saharan routes, or those of the Silk Road bordering the arid cold masses of Asia. Inhabitants of those way-stations often lived under the domination of trade masters, who sometimes settled them by force and enslaved them; the proximity of a region with heavy demographic pressure that needs to be alleviated can lead to a search for some potential resource exploitable at a high cost, but with good yields: a significant example of this is the lower Indus and its cotton fields linked to nineteenth century developments. Last but not least, the presence of heavily exploited mineral resources leading to the costly development of ‘mine camps’, in wholly artificial environments. In terms of the cost-benefit ratio, all these cases result in unusually high profits, at least for some of the actors.
More generally, we can say that, depending on the differential development costs arising over the course of time in individual technical frameworks, the different environments have undergone separate histories of development and population-building, differences which leave some marks today. Roger Dion has shown how the different environments of the Parisian basin, defined in terms of ground and underground, have actually known markedly different agrarian stories. Some of them, which he calls off-putting (unattractive), have regularly been the first sites to be abandoned and the last to be reoccupied, in relation to alternating periods of crisis and stability, of demographic decrease or demographic pressure, whereas the ‘attractive’ environments have experienced a parallel and inverse fate. Analyses of these types find-or should find-a broad field of application for explanatory geography research. It would obviously not be possible to develop this point further in the context of this brief note of definition.
The examples mentioned here have involved environments defined primarily in terms of their natural features. It is however not at all necessary to restrict the proposed reflection to environments of this type. In particular, it is obvious that marks imprinted by the past actions of different social groups deeply influence the costs of their development or re-development by contemporary societies. The differing fates of city-centres would provide an abundant source for reflection along these lines. The preservation of the site of Venice in its location at the remote end of the Adriatic Sea, with the heritage value attributed to its architecture, has led to constant, significant and widely-known development efforts, with more and extensive further development under consideration for the future. A completely different attitude may be found in other contexts, as for example in North-American cities, where the destruction and quick reconstruction of the centres themselves seem to be easily accepted.