Revised MeTHuVA method for assessment of tsunami human vulnerability of Bakirkoy district, Istanbul

Among the coastal districts of mega city Istanbul, Bakirkoy is one of the most critical one with the importance of air and marine transportation and presence of many other coastal facilities and structures that are prone to suffer from marine hazards. In the history, the Sea of Marmara has experienced numerous earthquake and landslide events and associated tsunamis. Therefore, tsunami risk assessment is essential for all coastal districts of Istanbul, including Bakirkoy district. In this study, a further developed methodology for tsunami human vulnerability and risk assessment Metropolitan Tsunami Human Vulnerability Assessment (MeTHuVA) is applied for Bakirkoy district of Istanbul, considering earthquake generated tsunamis. High-resolution tsunami hazard analysis is performed with the integration of coastal inundation computation with tsunami numerical tool NAMI DANCE and tsunami human vulnerability assessment with GIS-based multi-criteria decision analysis methods (MCDA). Using analytical hierarchy process method of MCDA, a hierarchical structure is established, composed of two main elements of tsunami human vulnerability: Vulnerability at Location and Evacuation Resilience. Tsunami risk assessment for Bakirkoy district is calculated by integrating result of hazard and vulnerability assessments with a risk relation that includes a parameter (n), which represents the preparedness and awareness level of the community. Tsunami simulations revealed that the maximum inundation distance is over 350 m on land and water penetrates almost 1700 m along Ayamama stream. Inundation is observed in eleven neighborhoods of Bakirkoy district. In the inundation zone, maximum flow depth is found to be over 5.7 m. The inundated area forms 4.2% of whole Bakirkoy district, and 62 buildings are located in the inundation zone. Hazard, vulnerability and risk assessment results for different neighborhoods of Bakirkoy district are presented and discussed.