Willingness to pay for upgrading tsunami co-beneficial structures: Example from a railway embankment and a revetment in Sri Lanka

Increasing the tsunami disaster resilience of the Southwestern coastline of Sri Lanka is a pressing problem, due to the continuous presence of unprotected human settlements in tsunami-prone areas. Even though a variety of different tsunami countermeasures can be attempted, due to budgetary limitations early warning systems are typically used. Some types of coastal structures (such as coastal railway embankments, revetments etc.) have the potential to mitigate the impact of tsunami, which is often overlooked in research. The engineering resilience of these structures needs to be improved if they are to withstand a tsunami, though upgraded structures can offer a multitude of co-benefits to residents. This research assesses residents willingness to pay (WTP) for hard defensive measures, as well as the socioeconomic factors that influence residents WTP. WTP of residents to upgrade a coastal railway embankment and a revetment in Dimbuldooa and Wenamulla villages was measured by conducting a structured questionnaire survey of 200 residents. The results of the survey were triangulated through five expert interviews with representatives of government agencies, construction companies and academia, and two focus group discussions with residents. The findings suggest that it is necessary for disaster risk managers to pay special attention to socioeconomic factors to successfully enhance the resilience of community.