Risk Perception and Preparedness for Volcanic Ashfall in Mexico City

Mexico City is located roughly 60 km from the Popocatepetl volcano. Since the volcano's reactivation in 1994, ashfall events have occurred at least 19 times in the city. The worst incident occurred in June 1997, which caused the local airport to close for ten hours and damaged several planes. However, in most cases, ashfall severity is based on the accumulated thickness which ranges from trace to dusting. These low-frequency and low-magnitude events have led to little interest from the Mexico City inhabitants in identifying the preventive measures during ashfall. Therefore, in this study we evaluate volcanic risk perception in residents of Mexico City through developing a survey that was published on diverse digital media. The survey was composed of open-ended and multiple-choice questions and consisted of four sections: demographic aspects, experience, perception, and knowledge of the volcanic phenomenon. Of the 4818 participants, demographic data showed more significant participation of people from 25-37 years old, women, and college education level. Two decision tree models have been obtained. The first admitted the knowledge of preventive measures as a variable that depends on preparation of a family when an ashfall occurs, memory of previously phenomenon, familiarity of the hazard map, awareness of who carries out the volcanic monitoring, and whether the family has perceived an ashfall before. The second considered that the belief about ash benefits was related to the experience and memory of any event. A logistic regression model was also performed to describe the knowledge of preventive measures before an ashfall event is influenced by two variables: the belief of respondents that this phenomenon can occur in their place of residence or work, and the idea of the possibility of a volcanic eruption. Moderate spatial correlations were discovered using Moran's I with variables like perception of ashfall, preparation for the time of an event, and knowledge of preventive measures for an ashfall. Our results indicate that the risk perception of volcanic ashfall was affected by the location where people live and related to memory and experience. It was observed that users' memory, experience, and beliefs have also influenced preparedness measures for an ashfall event.