Contribution of Ground Penetrating Radar in the study of an amazon tide channel, influenced by macro tide

This article shows the Ground Penetrating Radar (GPR) experiment applied in the Urumajó tidal channel (Augusto Côrrea, Pará, Brazil) that flows into the Caeté river estuary (Atlantic Ocean). This tidal channel has a length of 50 km (source - mouth, near Augusto Côrrea city) and a hydrographic basin of 544 km2. The GPR geophysical tool allowed extracting information under the depth of the channel bed in the various 2-D profiles. In the central part of the tidal channel, sediment accumulations were identified probably due to the influence of the tide. The results show that with the 200 and 400 MHz frequency antennas, the GPR is able to obtain records (radargrams) of the channel bed, over 7,5 m deep. During the rainy season, the tidal channel is covered by sand (30%) and mud (70%), however, in the dry season the muddy granulometric class (72%) increases a little and the sand (28%) decreases, sediments sludge predominated on the banks of the channel and increased upstream. The silting up of the tidal channel is a consequence of several activities carried out on the banks of the channel (livestock, agriculture, housing, ports, etc), resulting in deforestation.