Tectonic fault control of wetland distributions in the Central Amazon revealed by JERS-1 radar imagery

A mosaic of JERS-1 L-band synthetic aperture radar (SAR) images was used to investigate the influence of tectonic faults on wetland distributions in s imilar to 200,000 km(2) of central Amazon lowland (0-4 degrees Lat. S, 60-6 4 degrees Long. W). The geographic distribution of hooded wetland was clear ly evident on the mosaic due to the unique characteristics oil-band radar. Two distinct linear boundaries were encountered limiting the northern distr ibution of wetlands, one north of the Negro river main channel and west of the Branco river, oriented WNW-ESE, and one south of the Negro main channel and east of the Branco, oriented NW-SE. The orientations and positions of these boundaries were consistent with the prevailing tectonic fracture patt ern in the region. Geophysical, pedological and geomorphological data suppo rted the hypothesis that these boundaries are tectonically controlled. The ecological, economic and biogeochemical implications of the observed wetlan d distribution were considered. The distributions of wetland-dependent biot a were expected to be severely limited north of the Negro main channel. Fis h production, wetland timber yields and methane emissions were also predict ed to be exceptionally low in this region. (C) 2000 Elsevier Science Ltd an d INQUA. All rights reserved.