Models represent real-world events or objects. Hazard modeling can be problematic due to the complexities of nature (such as atmospheric conditions) and human factors (such as reactions to a hazard). Various Geographic Information Systems (GIS) can be used to illustrate the nature of such complexities. GIS is defined simply as an electronic map tied to a database. This electronic map is a representation of a place on the Earth in which the system may use points, lines, and polygons to represent objects. For example, a point may be a chemical plant, a line may be a road, and a polygon may be a city. Each of these representations is considered a layer, which can be overlain to get a better model of the Earth. The ...