Wetlands mapping in the Central African Congo River Basin using remote sensing multisource data

Wetlands are areas inundated or saturated by surface or ground water at a frequency and duration sufficient to support a prevalence of vegetation adapted for life in saturated conditions (Federal register, Circular 33; 1984). There is no clear boundary between open water and wetland on the one hand and wetland and terrestrial communities on the other hand (Bradbury and Grace, 1983). Wetlands are seen as diverse mosaics of landforms, communities and environments acting as interfaces between terrestrial and aquatic systems (Naiman et al, 1998; Junk and Piedade, 2005). Clement (1905) and Hansen and Di Castri (1992) use the concept of ecotone to represent them as tension zones between plant communities. Junk (1980) and Odum (1985) argue that wetlands have a status of specific ecosystems because soil water saturation, anaerobic conditions, and flooding, provide specific environmental conditions that result in specific biogeochemical processes, organisms specific adaptations, and particularities in community structure and development (Junk and Piedade, 2005; Junk, 1980; Odum, 1981). Flooded forests, also referred to as forested wetlands, are wetlands with a significant component of woody vegetation, living in temporarily or permanently waterlogged or inundated soils (Lugo, 1990; Beard, 1944; Naiman et al., 1998; Trochain, 1957).