Potential of Terrasar-x Imagery for Mapping Intertidal Coastal Wetlands

This work presents preliminary results about the use of TerraSAR-X imagery for mapping intertidal habitats (oyster parks, seagrass meadows of Zostera noltii, sediments) along coastal lagoons (Arcachon lagoon, France). The combination of SAR and optical data appears to be useful to improve the discrimination of the various sediment and vegetation covers into classification schemes. Unlike optical imagery which may lead to misinterpret sediment type, the potential of the multi-polarization SAR data is assessed notably regarding its efficiency for separating intertidal (Z. noltii) from supratidal salt-marsh vegetation species (spartina, salicornia, and so on). TerraSAR-X imagery is also an excellent highlighter of areas colonized by oysters (both cultivated and invasive ones) due to their relevant roughness signature among neighbored facies. In contrast, mapping methods based on optical data alone often do not perform well because of the presence of algae on oyster shelves. Moreover, potential exists for discrimating unvegetated soils but biofilm-covered from low-vegetated ones. As a conclusion, TerraSAR-X imagery offers many tracks to increase the performance of thematic mapping products along intertidal environments, in complement of optical data.