Incorporating Community Knowledge to Lahar Hazard Maps: Canton Buenos Aires Case Study, at Santa Ana (Ilamatepec) Volcano

Abstract:

Santa Ana (Ilamatepec) Volcano is an active composite volcano located in the Apaneca Volcanic Field located in western part of El Salvador, Central America. The volcano is surrounded by rural communities in its proximal areas and the second (Santa Ana, 13 km) and fourth (Sonsosante, 15 km) largest cities of the country. On October 1st, 2005, the volcano erupted after months of increased activity. Following the eruption, volcanic mitigation projects were conducted in the region, but the communities had little or no input on them. This project consisted in the creation of lahar volcanic hazard map for the Canton Buanos Aires on the northern part of the volcano by incorporating the community's knowledge from prior events to model parameters and results. The work with the community consisted in several meetings where the community members recounted past events. They were asked to map the outcomes of those events using either a topographic map of the area, a Google Earth image, or a blank paper poster size. These maps have been used to identify hazard and vulnerable areas, and for model validation. These maps were presented to the communities and they accepted their results and the maps.