Contenu du sommaire

Cartography, as a technique for selecting, organizing and stocking data in order to transmit them through time and space, has undergone many changes in the past decade. These changes have been mainly brought about by the introduction of telecommunications, computer technology and digital supports. Water is undoubtedly one of the most complicated elements with which the cartographer is confronted in the act of representing, as much the multiplicity of its forms as its changing relationship with the elements surrounding it, and even morese when, as in modern cartography, water must be represented as infrastructure. Using the cartography of Madrid as an example, the author follows the evolution of the representation of water in this city since the earliest images of the Manzanares River in the 16th century, until the publication of the GIS for the Isabel II Channel in 1993. She analyzes not only what has changed, but also what has been preserved in the representation of urban hydrography.

The application of fractal geometry to the modelling of some aspects of urban technical networks has developed only in the past decade. This theory makes it possible to take into account the apparent complexity of the spatial development of certain networks, such as roads, sewers, transportation networks, and so on. Insofar as the morphological aspects of these networks are concerned, the quantification of their form differs according to whether they are perceived as networks for exchange, or as networks for evacuation and distribution. Then one has either a dimension of contents, or else a dimension of localization. Since, in addition, the fractal dimension illustrates an allometric creative process for complex forms, we are invited to establish the connection between this theory and the question of the spatial growth of urban technical networks. This does not necessarily mean that one is obliged to ascribe to this theory the thesis of strictly endogenous development. There are at least two related processes which it is necessary to envisage. The first relates to principles which determine the organization of a base or primary structure, upon which develops a second process which may be related to the setting into place of a principle of more or less random ramification. Can one speak of a network effect in the context of spatial development?

In this paper we address the mutual relationship of transport network development and urban growth. This is done in the context of the railway system in the Netherlands in the nineteenth century. In order to analyze the impact of urban growth on network development, the network development in the Netherlands is simlulated using an algorithm based on the criterion of net returns on investment. Furthermore, the reverse relationship is investigated: the question addressed is to what extent the growth rates of cities in the Netherlands can be explained by factors such as the increase in accessibility by rail. The conclusion is that although the development of the railway network has had a significant impact on urban growth rates during several decades, its overall impact has been limited.

This paper seeks to explore and highlight the ways in which a competitive market, especially where the focus is on infrastructure competition in the UK, can lead to uneven investment in the "information superhighway". The key issue of concern here is the challenge that arises from infrastructure competition to universal service, in terms of availability, cost and quality. The paper argues that the "re-invention" of government and the associated development of new electronic-base, information-intensive services can act as a catalyst for new telecommunications investments which provide universal broadband services and a framework for new forms of government and community.