Impact on the Spatial Interpretation of Flood Hazard: Evaluating Depth and Depth–Velocity Classification Logics
Flood Risk - Assessment, Management Strategies, and Emerging Technologies, Editor, Editör, IntechOpen, London, ss.1-19, 2026
- Yayın Türü: Kitapta Bölüm / Araştırma Kitabı
- Basım Tarihi: 2026
- Doi Numarası: 10.5772/intechopen.1017686
- Yayınevi: IntechOpen
- Basıldığı Şehir: London
- Sayfa Sayıları: ss.1-19
- Editörler: Editor, Editör
- İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet
Özet
Flood hazard mapping is essential for identifying areas exposed to different levels of hydraulic intensity and supporting effective flood risk management and spatial planning. In this study, flood hazard in the lower Göksu River Basin, Türkiye, was assessed using a coupled HEC-HMS and HEC-RAS 2D modeling framework. Design flood hydrographs corresponding to 25-,50-,100-, and 500-year return periods were generated using HEC-HMS and implemented as upstream boundary conditions in HEC-RAS 2D simulations. The resulting flood depth and flow velocity outputs were integrated in a Geographic Information System (GIS) environment to generate flood hazard maps using two classification schemes: depth-based classification and depth– velocity-based classification. The objective was not to rank the two approaches but to investigate how different classification logics influence the spatial interpretation of flood hazard. Results showed that the depth-based approach classified a larger proportion of the inundated area as high and very high hazard. In contrast, the depth–velocity approach predominantly characterized the lowest hazard class. Nevertheless, the latter consistently identified localized very high hazard zones associated with hydraulically energetic areas. The total inundated area increased from 4.288 km² for the 25-year return period to 5.767 km² for the 500-year return period, indicating progressive expansion with increasing flood magnitude. Overall, the findings demonstrate that the selected classification scheme strongly influences flood hazard patterns. While depth-based classification emphasizes inundation severity, incorporating both depth and velocity provides complementary information on hydraulic intensity and helps identify critical areas, supporting informed spatial planning, mitigation prioritization, and flood risk management.