Phenomena - A visual environment for querying heterogenous spatial data

The need to perform complex analysis and decision making tasks has motivated growing interest in Geographic Information Systems (GIS) as a means to compare different scenarios and simulate the evolution of a phenomenon. However, data and function complexity may critically affect human interaction and system performances during planning and prevention activities. This is especially true when the scenarios of interest involve continuous fields, besides discrete objects. In the present paper we describe the visual environment Phenomena, where continuous and discrete data may be handled through a uniform approach. We illustrate how users' activity is supported by a visual framework where they can interact with, manipulate and query heterogeneous data, with a very small training effort. A preliminary experimental study suggests that when users perform complex tasks, a higher usability degree may be achieved compared to the adoption of a textual spatial SQL. (C) 2009 Elsevier Ltd. All rights reserved.