Wetlands of the Lowland Amazon Basin: Extent, Vegetative Cover, and Dual-season Inundated Area as Mapped with JERS-1 Synthetic Aperture Radar

• Published in: Wetlands (Wilmington, N.C.) Vol. 35; no. 4; pp. 745 - 756
• Main Authors: Hess, Laura L., Melack, John M., Affonso, Adriana G., Barbosa, Claudio, Gastil-Buhl, Mary, Novo, Evlyn M. L. M.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2015; Springer Nature B.V
• Subjects: Aquatic ecosystems; Aquatic plants; basins; Biomedical and Life Sciences; Clustering; Coastal Sciences; data collection; Datasets; Earth resources; Ecology; Environmental Management; Flood mapping; flooded conditions; Flooding; Floods; Forests; Freshwater & Marine Ecology; Hydrogeology; Image acquisition; Land cover; Landscape Ecology; latitude; Life Sciences; Macrophytes; Mosaics; Optical measuring instruments; Original Research; Regions; River basins; Rivers; Satellite imagery; satellites; Seasons; Sensors; Synthetic aperture radar; Vegetation; Vegetation cover; Videography; Watersheds; Wetlands; Woody plants; Radar remote sensing; JERS-1; Floodplain inundation; Amazon River; Tropical wetlands; Global Rain Forest Mapping Project
• ISSN: 0277-5212; 1943-6246
• DOI: 10.1007/s13157-015-0666-y

Wetland extent, vegetation cover, and inundation state were mapped for the first time at moderately high (100 m) resolution for the entire lowland Amazon basin, using mosaics of Japanese Earth Resources Satellite (JERS-1) imagery acquired during low- and high-water seasons in 1995–1996. A wetlands mask was created by segmentation of the mosaics and clustering of the resulting polygons; a rules set was then applied to classify wetland areas into five land cover classes and two flooding classes using dual-season backscattering values. The mapped wetland area of 8.4 × 10 5  km 2 is equivalent to 14 % of the total basin area (5.83 × 10 6  km 2 ) and 17 % of the lowland basin (5.06 × 10 6  km 2 ). During high-water season, open water surfaces accounted for 9 % of the wetland area, woody vegetation 77 %, and aquatic macrophytes 14 %. Producer’s accuracy as assessed using high-resolution digital videography was better than 85 % for wetland extent. The mapped flooding extent is representative of average high- and low-flood conditions for latitudes north of 6° S; flooding conditions were less well captured for the southern part of the basin. Global data sets derived from lower-resolution optical sensors capture less than 25 % of the wetland area mapped here.