Dinâmica fluvial e aspectos antrópicos no Furo do Paracuúba, Iranduba/AM

Abstract

The “Furo do Paracuúba” is located in the city of Iranduba, about 28 km far from the Manaus’ Port, as an important connection between the Solimões River and the Negro River and shortening distances, by serving as a route for regional and express vessels (jet), mainly during the flood. Due to the many forms of interactions between human action and the natural environment, the work presented has the main objective of analyzing the fluvial dynamics of the channel and related processes, seeking to explain its main hydrodynamic, sedimentological, geomorphological and anthropic aspects. For this, the following methodological procedures were adopted: width measurement; length; sinuosity index; area and mapping of land use and coverage from satellite images of the multitemporal series (2006, 2008, 2010, 2016 and 2018), bathymetric surveys; chain speed tests and water sample collections; average flow estimates; concentration of suspended total solids; solid discharge; water transparency and pH estimates. These data were obtained from three cross sections (entrance, middle and exit), and are representative of three periods of the hydrological regime (ebb start, ebb end in 2018 and flood in 2019), application of questionnaires to owners and / or vessels owners that navigate the channel; daily vessel flow counts; check of the granulometry; real and apparent density and total porosity of soil samples collected on the banks of the channel; tests of resistance to penetration and infiltration in the soil; monitoring of two piezometers installed on the banks; mapping of erosion and deposition areas using satellite images and mass wasting scars using the UAV-LATOSSOLO and application of questionnaires to the residents of the communities covered by the channel. The results of the study made it possible to conclude that the constant actions operated in the channel, both natural and human, have implied new adjustments of its morphometry, mainly with the increase in width and disproportionate changes in its geomorphic processes, where erosion and / or mass wasting (with extensive scars of the slide rotacional types) occurs intensively in the channel, in its entrance and middle portion, to the detriment of deposition in its final part, affecting the way of life of residents and river navigation. Keywords: channel; Fluvial Geomorphology; river erosion, mass wasting