Uncertainty analysis of environmental models within GIS environments

Information on the uncertainties in results from Geographic Information Systems (GIS) is needed for effective decision-making. Current GISs, however, do not provide this information. Uncertainties in application models used within GIS environments are a major cause of uncertainties in GIS results. To analyze model uncertainty and its propagation, model sensitivity analysis is first performed. This paper discusses techniques for model sensitivity analysis, model uncertainty analysis, and analysis of the propagation of model uncertainty, within the context of environmental models used within GIS. A two-dimensional air quality model, based on the first-order Taylor method, is used to demonstrate these techniques. (C) 1998 Elsevier Science Ltd. All rights reserved.