Geographical knowledge, which is highly important to emergency management, has been affected by recent technological advances in spatial data processing, including: 1. computer cartography, 2. computer graphics, 3. digital remote sensing, 4. geographic information systems, 5. spatial statistics, and 6. quantitative spatial modeling. Geographical data can be used in more ways than before, and technical specialists continue to develop increasingly flexible and powerful tools that allow emergency managers to examine multiple-parameter scenarios in both human-caused and natural disasters. A look at the impact of some of the changes indicates the importance of establishing a coordination center and geographical information network with appropriate computer support and staff expertise. This would speed up calculations and judgments, improve identification of impact areas, and create a common set of information for planners and decision makers at all levels of authority.