Scenario-based tsunami risk assessment using a static flooding approach and high-resolution digital elevation data: An example from Muscat in Oman

Abstract

Knowledge of tsunami risk and vulnerability is essential to establish a well-adapted Multi Hazard Early Warning System, land-use planning and emergency management. As the tsunami risk for the coastline of Oman is still under discussion and remains enigmatic, various scenarios based on historical tsunamis were created. The suggested inundation and run-up heights were projected onto the modern infrastructural setting of the Muscat Capital Area. Furthermore, possible impacts of the worst-case tsunami event for Muscat are discussed.The approved Papathoma Tsunami Vulnerability Assessment Model was used to model the structural vulnerability of the infrastructure for a 2m tsunami scenario, depicting the 1945 tsunami and a 5m tsunami in Muscat. Considering structural vulnerability, the results suggest a minor tsunami risk for the 2m tsunami scenario as the flooding is mainly confined to beaches and wadis. Especially traditional brick buildings, still predominant in numerous rural suburbs, and a prevalently coast-parallel road network lead to an increased tsunami risk. In contrast, the 5m tsunami scenario reveals extensively inundated areas and with up to 48% of the buildings flooded, and therefore consequently a significantly higher tsunami risk. We expect up to 60000 damaged buildings and up to 380000 residents directly affected in the Muscat Capital Area, accompanied with a significant loss of life and damage to vital infrastructure.The rapid urbanization processes in the Muscat Capital Area, predominantly in areas along the coast, in combination with infrastructural, demographic and economic growth will additionally increase the tsunami risk and therefore emphasizes the importance of tsunami risk assessment in Oman.