Abstract: The present invention provides a tool to depict the relative impact to the losses of a insurer's portfolio from catastrophic events, such as a hurricanes or earthquakes, at a specific risk level by geographic area using a grid level database and a spatial database to generate maps. The maps developed using this tool help visualize the potentially dangerous areas for writing new business and/or identify preferential places for growth. The tool also creates a list of zip codes with incremental losses at a particular risk level representing the relative attractiveness of writing new policies (or eliminating existing policies) in one zip code versus another. The spatial database provides rich spatial geometry features in the form of raster images available in the spatial database and the invention provides the corresponding spatial algebra to create relativity maps with gradient features and zip code loss information.