GIS Based Chemical Fate Modeling: Principles and Applications

Chapter 3

Basics of GIS Operations

3.1 What is GIS?

Geographic information systems (GIS) have evolved since the seminal experience of Roger Tomlinson for the Canadian Government in the early 1960s [1]. GIS is usually defined as a software and hardware system aimed at storing, representing, and manipulating spatial data. However, this rather technical connotation of GIS does not account for the rich debate that has been stimulated among geographers, planners, and policy makers by the development of technologies enabling geographic representations over the last 20 years. Perhaps due to the inherent lure of maps, the immediacy of the message they convey, and their capacity to stimulate intuitive and nondisciplinary reasoning, phenomena represented in maps have more impact.

GIS technology does not simply enable spatial chemical fate modeling in a more user-friendly way than numerical models: it stimulates a different approach to modeling, where the combination of geographic information replaces more traditional modeling techniques and enhances model transparency, usability, and relevance to decision making.

The perception that making maps and studying geographic phenomena quantitatively implies much more than mastering GIS software justifies the attempts at theoretical systematization of the concepts, techniques, and methods incorporated in GIS, as if it were a discipline in itself. In the last decades, following the paper by Michael Goodchild in 1992 [2], the acronym GIS has been ...