Visual representations of the dynamics of territories: retrospective and input of new computing environments
ISBN 978-85-88783-11-9
Authors
1Davoine, P-A.; 2Mathian, H.; 3Saint-Marc, C.; 4Blaise, J-Y.; 5Kadour,i L
1GRENOBLE-ALPES UNIVERSITY, LIG Email: paule-annick
2UMR 5600 ENVIRONNEMENT VILLE SOCIÉTÉ, LYON, Email: helene.mathian@ens-lyon.fr
3LIG Email: cecile.saint-marc@imag.fr
43UMR 3495 MAP – GAMSAU Email: jean-yves.blaise@map.archi.fr
5UMR CNRS 7300 ESPACE - UNIVERSITÉ D'AVIGNON Email: lahouari.kaddouri@univ-avignon.fr
Abstract
Nowadays, we are confronted with a wide diversity of available data, that is often massive data. For these data, visualization enables to identify structures, dynamics and relations. Spatio-temporal data is not exempt from this trend. It is now well established that visualization of spatial dynamics contributes to their analysis, by highlighting transformations, modifications and evolutions of spatial organizations. These may correspond to diffusion processes, ranking processes, movements, that may be observed either on a long term period (historical periods, centuries) or on a short term period (day or month). Exploring, analyzing in order to identify and understand multiple temporalities of a territory toile on mobilization of spatio-temporal data. Since Peuquet (1984), it is a common practice to deal with such data according to three dimensions: time (when), space (where) and theme (what). This is the case with the impact of global warming on the earth over time (large scale), but also for monitoring traffic evolutions on small roads in a small region (small scale). Thus, the issue of representing temporalities depends on the diversity of these questions and of these spatial and temporal scales. However, representations should abstract from these different scales to focus on a common need: to consider Peuquet’s three dimensions. Recent technological advances offer new possibilities of cartographical representations of timescales, especially through the arrival of animated cartography and geovisualisation platforms. Nowadays, a large diversity of cartographical developments attempt to integrate time in their cartographical representations. But these questions of representing time and timescales aren’t new. New capabilities reside today in calculation capacities, real time visualizations, adaptable interfaces… Beyond them, lots of visual solutions have been proposed, often very smart, that carry out reasoning on both space and time in a very efficient and effective way. This is the case for example of the cartographical representation of the retraite de Russie map by C.J. Minard (1865) or the train schedule by E.J. Marey(1885). These representations constitute a heritage for visualizations. They can be categorized in three large families of uses: chronographic, cartographic and statistic. This article deals with a state of the art in the area of past and current spatio-temporal visualizations. We first propose a set of crossed chronological references, that illustrate these different approaches. The aim is not to be exhaustive or representative, but to highlight the existing kinds of temporal visualizations. The examples will focus on two categories, which are the time dominant one and the space dominant one. Some emblematic cases of spatio-temporal representations will be detailed, while making connections with how other domains (SciViz, InfoViz) deal with them. Thus, we wonder if this whole heritage constitutes the foundations of cartographical explorations. In a second step, we propose an analysis of a selection of websites, that show dynamic cartographical visualizations. This set of visualization will be analyzed according to criteria, which cover proposed functional features, semiological innovations, and services delivered. A “dataviz” like interface, that was developed in this project, is presented to explore all these descriptors. On one side, these characteristics will be compared to the previous description of what we called the cartographical heritage. On the other side, we propose to position them within the “cube” proposed by MacEachren (1984), which constitutes a conceptual reference for the cartographical practices.