Vulnerability and Risk Assessment to Hydrometeorological Hazards in the City of Naga, Cebu, Philippines

The global temperature has risen rapidly over the past years. It contributes to climate change and poses an increase in the number and scale of disasters. On September 20, 2018, a massive landslide devastated the City of Naga and claimed the lives of 78 people. With this, the city government of Naga and the University of the Philippines Resilience Institute conducted a Climate and Disaster Risk Assessment (CDRA) to analyze and mitigate the impacts of natural hazards intensified by climate change. Part of the CDRA process is the exposure database development which provides baseline information to each exposure unit. Four hydrometeorological hazards, flood, rain-induced landslide, storm surge, and storm surge with sea-level rise, were assessed in the CDRA for the City of Naga. The study also incorporated the climate change projections from the Intergovernmental Panel on Climate Change, specifically the Representative Concentration Pathways (RCPs) 4.5 and 8.5. This study simulated a total of fifteen scenarios for each hazard using baseline data and RCP 4.5 and RCP 8.5 models, which include five-year, 25-year, and 100-year rainfall return periods (RRP). The vulnerability assessment uses the function of exposure, sensitivity, and adaptive capacity. The risk assessment, on the other hand, uses the function of the likelihood of occurrence and severity of the consequence of each hazard. The results of the CDRA show that the vulnerabilities and risks of the barangays (villages) in the City of Naga generally increase as the climate change scenario increases. The City of Naga formulated various risk-sensitive policy interventions to prepare for the climate change impacts and disaster risks in the future. These include, but not limited to, the establishment of  no-build zones, strict compliance to national laws, and mandatory evacuation of households in high-risk areas during heavy rainfall events.