Using mixed-methods to understand community vulnerability to debris flows in Montecito, CA Erica Akemi Goto, Summer Gray, Edward Keller, Keith C. Clarke Abstract More communities around the world are living in hazard-prone areas. Therefore, they are susceptible to natural hazards and negative impacts, which can be mitigated by adopting Disaster Risk Reduction measures that take into account an assessment of vulnerability. However, vulnerability studies can be limited and often do not take a spatio-temporal approach. In this study, we applied a spatio-temporal approach to the case of Montecito, CA, in order to better understand the variables that make a community vulnerable and to identify those who are the most vulnerable. In 2018, Montecito was heavily impacted by debris-flows resulting in material and human losses. Our results showed that informal workers, residents of voluntary evacuation areas, and renters were most vulnerable, and the main aspect that contributed to their vulnerability was a lack of understanding of debris-flow risk. Moreover, local authorities failed to use historical data to communicate and educate the community before the event to reduce the overall community vulnerability and rebuilding process is changing the community vulnerability. Keywords Montecito, debris-flows, vulnerability, mixed-methods, spatio-temporal Introduction “Even when they said the rains were coming, you don’t expect a mountain to come down.” (Respondent 04) Natural hazard events impact communities negatively around the world. The increase in negative impacts in these communities is linked to the increase of population and, consequently, more people living in at- risk areas. There are multiple ways to assess risk, but the framework we are using to understand risk is the one that combines hazardous events and vulnerability (Maskrey, 1989; Wisner et al., 2003). Hazardous events will continue to be hazardous, but a better assessment of vulnerability can prevent disasters by building stronger and more resilient communities. Vulnerability assessment is part of Disaster Risk Reduction (DRR) measures. A good vulnerability assessment should consider all members of the community, the local dynamic, and particularities of geography. Broad quantitative vulnerability assessments consider the spatial extent of the community but do not consider the local socio-economic heterogeneity. Using the same variables to assess vulnerability nationwide can help researchers understand general vulnerability patterns, but not specific details, which can include cultural or local dynamics. General assessments have no tools to include the marginalized populations within a community, and these are usually the most vulnerable (Wisner, 1998). For instance, the homeless during the Tokyo earthquake (Wisner, 1998) or informal workers during a wildfire (Thomas fire) in Ventura and Santa Barbara Counties, CA. Not including the marginalized populations continues to maintain them as marginalized, and when they survive a natural disaster impact, they do not recover their livelihoods (Wisner & Luce, 1993), and become even more vulnerable. Therefore, quantitative and qualitative assessments targeting the local community can tell a better story about community vulnerability. In this study, we do not aim to assess vulnerability but rather to demonstrate how a temporal-spatial approach that considers the type of natural hazard combined with a mixed-methods study can enhance understanding of community vulnerability. Considering Montecito and the 2018 debris-flows, we aim to answer the following questions: 1) Who were the most vulnerable people? 2) What were the characteristics of the community that made it more vulnerable? We used a parallel mixed-method approach to explore in-depth the particularities of the local community and develop a Manuscript - please use a template Click here to access/download;Manuscript - please use a template;montecito_20200307.docx Click here to view linked References 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65