DOI: 10.14457/tu.the.2016.517
title: Understanding evacuation decision, departure timing and destination choice of households in high flood risk areas using discrete choice model

description: A number of Asian countries has experienced catastrophic disasters in the recent past. Hydro-meteorological disasters such as typhoons and floods were the most prevalent disasters that caused havoc to these countries among other disaster types. Evacuation is an essential preparedness measure in disaster management. Involving complex behavioral considerations, it requires careful modeling and planning to minimize chaos and confusion during evacuation operations. Effective modeling of evacuation travel behavior depends on effective modeling of evacuation aspects including the decision whether to fully or partially evacuate or stay in the area threatened by hazard, evacuation timing, destination type choice, mode and route choice. Using discrete choice models, this study seeks to investigate the behavioral complexities focusing on the first three decisions in the first stages of evacuation demand modeling. Data was collected through a face to face post-event survey from flood affected households in Quezon City, Philippines. Results show that evacuation decision is determined by a combination of household characteristics and capacity-related factors (gender, educational level, presence of children, and number of years living in the residence, house ownership, number of house floor levels, type of house material), as well as hazard-related factors (distance from source of flood, level of flood damage, and source of warning). Results of the binary logit model estimates for departure timing indicate that households put importance on hazard-related factors and their capacity to cope with flood when making their decisions. Factors that determine the flood evacuation departure time constitutes the type of work of the head of the household, house ownership, the number of house floors, distance of their homes from the source of flood, and the flood level. On the other hand, the multinomial logit evacuation destination model estimates show capacity related characteristics (income, presence of flood equipment), hazard-related factors (distance from the source of hazard, source of warning) and evacuation destination specific characteristics (cost, travel distance to destination and duration of stay at the destination) as factors that are significant to this type of choice.Findings in this research provide useful insights for evacuation managers and planners in preparing for future flood evacuations. Insights in evacuation decision can be used to design appropriate programs to encourage full evacuation compliance of households especially those that live nearest to the flood source, as well as those who have houses with 2 or more floor levels. Evacuation planners can also develop alternative strategies to increase full evacuation compliance of households with children since these households seem less likely to fully evacuate. Evacuation compliance of households can be improved through the design and conduct of educational programs to increase awareness about hazards and disasters and enhance preparedness for future evacuations. People with disaster education are those who are best prepared and capable to manage a disaster, they may also be more willing to take preventive measures. In terms of departure timing, authorities could design appropriate strategies to encourage those that are living very near the source of flood and have house floor levels more than a floor to evacuate immediately once the government recommended them to evacuate. This can be done by educating and/or providing them with benefits of evacuating earlier such as highly prioritizing them to be moved to secured evacuation centers with provision of vehicles as needed, food, water, medical assistance and other basic needs. Households that own their house can be encouraged can be involved in leading evacuation movements in the future. In order to encourage households who are renting their homes to also evacuate well ahead of time, security guards should be provided in areas of residence to keep them from worries of looting and house security. Above all, government officials, when issuing future evacuation advice, should also specify the timing of evacuation by specific groups of households in addition to other evacuation related content of the message (e.g. routes to take when evacuating according to specified destinations such as evacuation centers). The model developed here can be used to predict the number of households evacuating at specific timing which can be utilized to plan for staged evacuation movement in the future. Findings from the destination analysis can be used by the government to prepare evacuation warnings with concrete information to communicate to people in order to be prepared ahead of time. They could also encourage those who have been going to friends/families in order to decrease the demand of going to public evacuation centers. In this sense, the government could also prepare for the supplies such as food, water and medicine and be able to let evacuees have better situation during future evacuations. This in turn could reduce the necessity of large numbers of public shelter/church facilities. Models developed in this study and its predictive ability and specifications were also validated.