The Digital Urban Atlas of Jeddah: Some Raised Issues and <i>Semiological</i> Principles

Abstract

The “Technological Transition” has had a tremendous impact on cartographic processes and outputs. Atlases, whether national, regional or urban, were affected as they moved from a static to an animated and interactive era. The overall posi tive development, consolidated by map automation and map animation, has taken various forms and directions. Nevertheless, some graphic and cartographic outputs, especially atlases, still suffer from serious pitfalls, regarding some semiological aspects of the resulting maps and graphics. The Digital Urban Atlas of Jeddah (DUAJ) is a research in progress aware of such deficiencies. It tries to spare it from some frequent errors in map design related to: the choice of the base map, the use of some frequent symbols such as columns and pie charts for multivariate quantitative data, and the alternative solutions to choropleth maps. These deficiencies are selected and examined among others. The authors are convinced that the generated maps and diagrams that should be produced in digital atlases must be examined with regards to the semiological rules that drew upon the theory of signs perception. They try to incorporate the basic principles of graphic semiology reviewed, corrected and adapted to the GIS requirements. This is also meant to avoid map noises and deficiencies. The goal is to attract future Digital Atlases producers towards developing higher interest in map look and design and users to grasp messages rapidly. Specifically, the use of GIS and linked spatial databases within the DUAJ should not pay attention only to data handling and crossing, but also, to the semiological features of the outputs and relevant visual communication. In its preliminary stage, the DUAJ should give answers not only to the three questions raised in this research but also to others not examined here. This is to prevent from incorrect, irrelevant or inadequate use of the cartographic tools and, following the analysis of concrete examples, to propose a set of recommendations in establishing maps and graphics. When necessary, the DUAJ GIS-based outputs are inserted in CAD or CAC systems to benefit from some their specific visual tricks and subtleties that yield better legibility and efficiency of communication for Atlases users as recommended by authors. This experience is discussed regarding its eventual contribution to better map reading through some examples of maps and graphics from the DUAJ project (in progress).