What Is the Shape of Geographical Time-Space? A Three-Dimensional Model Made of Curves and Cones

Abstract

Geographical time-spaces exhibit a series of properties, including space inversion, that turns any representation effort into a complex task. In order to improve the legibility of the representation and leveraging the advances of three-dimensional computer graphics, the aim of the study is to propose a new method extending time-space relief cartography introduced by Mathis and L’Hostis. The novelty of the model resides in the use of cones to describing the terrestrial surface instead of graph faces, and in the use of curves instead of broken segments for edges. We implement the model on the Chinese space. The Chinese geographical time-space of reference year 2006 is produced by the combination and the confrontation of the fast air transport system and of the 7.5-times slower road transport system. Slower, short range flights are represented as curved lines above the earth surface with longer length than the geodesic, in order to account for a slower speed. The very steep slope of cones expresses the relative difficulty of crossing terrestrial time-space, as well as the comparably extreme efficiency of long-range flights for moving between cities. Finally, the whole image proposes a coherent representation of the geographical time-space where fast city-to-city transport is combined with slow terrestrial systems that allow one to reach any location.

Vers une transformation géométrique géocentrique des espaces urbains : la ville vue à partir du ou des centre(s)

“…De nombreux auteurs ont pu depuis proposer des méthodes de déformation cartographique pour représenter ce nouvel espace. A ce titre, on citera les travaux très récents de L'Hostis et al 1 [1] (qui reprennent pour partie la thèse de L'Hostis sur les représentations de la distance temps en en améliorant les principes). On pourra également citer les travaux de déformation des réseaux (distance temps centrée) par Kaiser et al [2].…”

Visualization and Analysis of Transport Accessibility Changes Based on Time Cartograms

“…Time geography allows the researcher to examine the complex interaction between space and time and their joint effect on the structure of human activity patterns in particular localities [6]. However, it is more focused on understanding and modelling movement and its constraints than on producing a new representation of time-space [7].…”