COMPARATIVE FLOOD MAPPING USING SAR IMAGES: THE SANTA LUCIA RIVER CASE

Floods are among the most frequent and widespread hazards worldwide. An increase in flood events is anticipated due to population growth in exposed areas, economic growth and climate change (Rojas et al., 2022). This study aims to compare the capabilities of C- and L-band synthetic aperture radar (SAR) images for flood mapping. This approach provides insight into the conservation of river wetlands and contributes to land use planning by minimizing urban development in areas prone to frequent flooding. To achieve this, maps depicting changes in the sigma 0 coefficient were generated using SAR images captured at two frequencies: C-Band and L-Band, under both flood and non-flood conditions. Subsequently, dominant interaction mechanisms between the backscatter coefficient sigma 0 and the existing vegetation were analyzed. combined with statistical criteria thee analyses facilitated the generation of flood maps. Ground truth points reflecting flood extent as reported by local residents and previously conducted flood mapping in the area, demonstrated, the superior performance of the L-Band in detecting flood extent. However, both systems showed significant sensitivity to flood conditions.