Flood vulnerability reduction, using a partial participatory GIS approach. A study case in Baja California Sur, Mexico

Abstract

A partial participatory GIS approach was implemented in a community in La Paz, Baja California Sur, Mexico to reduce vulnerability of floods caused by cyclones. A workshop was held to locate areas susceptible to floods, and understand measures already taken by the community as well as actions proposed towards vulnerability reduction. We used printed high-resolution satellite images and generative tools to gather data of workshops attendees. Then all information was transferred into a GIS. In addition, we conducted a survey to collect socioeconomic and adaptation data on 490 households (each one identified and spatially located). We analyzed through "chi square" and "gamma tests" the relationship between survey data and houses affected by floods. The map generated was reviewed by risk management experts and used as an input for map validation/refinement from the workshop. The final map was returned to the community and used as an instrument for communication, negotiation, risk management and vulnerability reduction, making spatially explicit areas affected by floods and proposed measures to reduce vulnerability. Despite not finding a statistical (corelation) between the participants education and socio-economic levels or preparedness for risk and the affectations (impacts) by floods. The majority of people showed to be used to local knowledge preventive measures in their household under a cyclone alert and answered to feel prepared to a cyclone arrival. This cyclone awareness could be explained since in this community 40% of the people had at least 12 years of education. Which is relatively high for a developing country as Mexico where the average of years of study is 9.1. Besides 87% of the people get a medium to high value in a socioeconomic index created in this study.