Integrated Risk Assessment to Natural Hazards in Motozintla, Chiapas, Mexico
Abstract
An integrated risk assessment includes the analysis of all components of individual constituents of risk such as baseline study, hazard identification and categorization, hazard exposure, and vulnerability. Vulnerability refers to the inability of people, organizations, and societies to withstand adverse impacts from multiple stressors to which they are exposed. These impacts are due to characteristics inherent in social interactions, institutions, and systems of cultural values. Thus, social vulnerability is a pre-existing condition that affects a society's ability to prepare for and recover from a disruptive event. Risk is the probability of a loss, and this loss depends on three elements: hazard, exposure, and vulnerability. Thus, risk is the estimated impact that a hazard event would have on people, services, facilities, structures and assets in a community. In this work we assess the risk to natural hazards in the community of Motozintla located in southern Mexico in the state of Chiapas (15.37N, 92.25W) with a population of about 20 000 habitants. Due to its geographical and geological location, this community is continuously exposed to many different natural hazards (earthquakes, landslides, volcanic eruptions, and floods). To determine the level of exposure of the community to natural hazards, we developed integrated studies and analysis of seismic microzonation, landslide and flood susceptibility as well as volcanic impact using standard methodologies. Social vulnerability was quantified from data obtained from local families interviews. Five variables were considered: household structure quality and design, availability of basic public services, family economic conditions, existing family plans for disaster preparedness, and risk perception.The number of families surveyed was determined considering a sample statistically significant. The families that were interviewed were selected using the simple random sampling technique with replacement. With these procedure, each household was chosen randomly and entirely by chance with the same probability of being chosen at any stage during the sampling process. To facilitate our interpretation, all results were spatially analyzed using a Geographical Information System (GIS). Our results indicate that the community of Motozintla is higly exposed to floods, landslides and earthquakes and to a lesser extent to the impact of a volcanic eruption. The locality has a high level of structural vulnerability to the main identified hazards (floods and landslides). About 70% of the families has a daily income below 11 USD. Approximately 66% of the population does not know any existing Civil Protection Plan. Another major observation is that the community organization for disaster prevention is practically nonexistent. These natural and social conditions indicate that the community of Motozintla has a very high level of risk to natural hazards. This research will support decision makers in Mexico, and particularly from the sate of Chiapas, in the development of an integrated comprenhensive natural hazards mitigation and prevention program in this region.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMNH43A1623N
- Keywords:
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- 4328 NATURAL HAZARDS / Risk;
- 4330 NATURAL HAZARDS / Vulnerability;
- 4333 NATURAL HAZARDS / Disaster risk analysis and assessment;
- 4339 NATURAL HAZARDS / Disaster mitigation