Flood hazard assessment in the Danube Delta using 2D hydraulic modeling

The study analyzes flood risk in the Danube Delta, a fragile ecosystem at the intersection of natural processes and anthropogenic interventions, increasingly exposed to the effects of climate change. Using 2D hydraulic modeling with HEC-RAS software, the research assessed the extension of floodplains for 10, 100 and 1000-year return periods, based on hydrological data collected between 1971 and 2005. The results obtained demonstrate a significant increase in the areas affected by floods, especially in scenarios with a low probability of occurrence, thus highlighting the increased vulnerability of the region to extreme phenomena. Analysis of water depth in flooded areas indicates that regions with intermediate depths (0.2–0.5 m) are most affected by 100-year flood events, while rare events (1000 years) extend the impact to larger areas and greater depths (0.5–1 m). This evolution confirms the trend of increasing risks in the context of climate change and the increase in the frequency of extreme hydrological phenomena. The hazard maps generated are an essential tool for flood risk management, supporting informed decision-making to protect local communities and the delta’s biodiversity. Among the solutions proposed to reduce the impact of floods are the ecological reconstruction of wetlands, the implementation of effective climate change adaptation policies and the improvement of water management strategies. The study also highlights the need to integrate additional factors, such as the influence of the Black Sea level, in future simulation models, for better risk anticipation and optimization of protection measures.