Modeling Oil Spill Trajectories for Hazard and Risk Assessment in the Coastal Area of Khanh Hoa – Nha Trang

Oil spills pose significant threats to coastal ecosystems and socio-economic activities, yet integrated assessment approaches remain limited in Vietnam. This study presents a combined framework using the OpenDrift oil spill trajectory model and the Environmental Sensitivity Index (ESI – NOAA) to evaluate the potential impacts of a hypothetical spill in Nha Trang Bay. A 15-day simulation demonstrates a predominant southward drift, with oil slicks exposing sensitive habitats such as coral reefs, seagrass beds, and aquaculture areas. By overlaying the modeled spill distribution with the ESI map, we calculated a risk index (RI = CI × SI × EI) that accounts for oil contact frequency, ecosystem sensitivity, and exposure duration. The results highlight several hotspots of very high risk, notably around Hon Mun and the eastern shoreline of Nha Trang Bay. The proposed approach provides a reproducible tool for spatially explicit oil spill risk assessment, supporting contingency planning and environmental protection in Vietnam’s coastal zones.