Pedro Walfir M. Souza Filho

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Based on the integration of geological information, the pollen record, radiocarbon data, and modern mangrove distribution, this paper proposes a model of evolutionary development for mangroves on the Brazilian Bragança Peninsula driven by relative sea-level changes from the middle to late Holocene. After a postglacial relative sea-level rise (RSL), the(More)
Orbital remote sensing data were assessedfor mapping of the main geomorphologicaland vegetation units of the Bragançapeninsula (North Brazil), which belongs toa vast though sparsely mapped mangrovecoast. Wide wetland environmentscharacterize the region with extremevariations in extension, temporalevolution, and spatial complexity. Thiswork was based on(More)
The aim of this study is to understand the relationship between radar backscattering (σ ̋, β ̋ and γ) of a multi-polarized Radarsat-2 C-band image with the structural attributes of regenerating mangrove vegetation located at the mouth of the Amazon River. CBH (circumference at breast height), height and species data were collected to characterize vegetation(More)
Amazonian aquatic systems are usually associated with pristine waters, however, irregular urban occupation of the hydrographic basins and sewerage deficiencies may lead to point and diffuse contamination. Sewage contamination in intertidal surface sediments from the Guajará Estuary, Brazilian Amazon coast, was evaluated using a set of steroids as(More)
The stability of the broad-spectrum antibiotic ceftiofur was studied in order to investigate the kinetics of photodegradation of this drug, using a stability-indicating liquid chromatography (LC) method. The degradation was carried out in aqueous solutions, prepared from reference substance and two pharmaceutical products (Excenel and Topcef) containing(More)
Accidental oil spills may impact sensitive wetlands in the Amazon coast. To generate an environmental sensitivity index (ESI) maps were used: (1) JERS-1 SAR data; (2) RADARSAT-1 data in the W1 beam mode; (3) X-band mosaics of the RADAM Project; and (4) SRTM digital elevation models. As result was identified artificial structures (break water and peers) and(More)
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