This paper explains how risk analysis has been added to a Geographic Information System (GIS) by integrating dynamic simulation models. The GIS application provides geographic information from an area in the map, which is selected by the user, and retrieves the results of the simulation in return. These dynamic results may be displayed on the map, possibly in combination with relevant static information from other data sources available to the GIS system, for instance, population density and area development plans. The solution is a result of a commercial collaboration between the two Norwegian software vendor companies, Norkart AS and Powersim Software AS. Norkart is responsible for the GIS part of the solution through their GIS application GIS/LINE. Powersim Software provides the simulation capabilities through their simulation software Studio 7. Based on requests from Norkartís customers for risk analyses, two models were developed; 1. The first model simulates the movement of water through soil to identify the risk of landslide. 2. The second model simulates the diffusion and movement of poisonous gases, based on gas types, wind force and wind direction. The solution can easily be extended to cover other problem areas, like flooding and oil spill.