Display of the Nevado del Ruiz Volcanic Hazard Map Using GIS

The November 13, 1985 Nevado del Ruiz volcanic eruption that killed approximately 25.000 people was the fourth largest volcanic disaster in human history. Different versions of the volcanic hazard map of this volcano were prepared before and after the disaster, being the first map of its kind made in Colombia. Preparation of the hazard maps was not timely, and there was poor dissemination of its content. The Volcanic Hazard Map of Nevado del Ruiz Volcano was recently incorporated into a GIS, in order to make it accessible to both casual and expert users. It was simplified showing only the zones likely to be affected by given volcanic processes. For the volcano's area of influence, perspective views were generated by combining topographic data with the hazard map polygons superimposed on a Landsat TM 5 mosaic. Database visualization in 3‐D enabled complex volcanic hazard data, to be more readily understood by decision makers and the general public.