Análise Espaço-Temporal da Pluma de Dispersão dos Sedimentos Dragados do Porto de Maceió, Alagoas

Abstract

The understanding of the sedimentary dynamics is important in the characterization of impacts caused by dredging and this knowledge becomes decisive for their discernment. The aim of this article was to analyze the plume of dispersion of the sediments of the Port of Maceió. The analyzes were carried out in three sampling campaigns, before, during and after the port works, in which the collection points in the dredging and discard areas were plotted. The suspended particulate material (SPM) was analyzed using the gravimetric method and in situ sampling of the parameters turbidity, dissolved oxygen and percentage of saturation, salinity and electrical conductivity with a multiparameter probe and water transparency with Secchi disk. The parameters SPM, turbidity and transparency were analyzed by linear interpolation, while the other variables were subjected to analysis on a polynomial calibration curve. The multiparameters worked were submitted to box plot analysis in order to assess the variance between campaigns. The variation of SPM in the sample campaigns showed dynamic spatial and temporal behavior; The interpolation promoted a better visualization of the physical parameters that directly express the plume of dispersion; The supplementary variables showed trend patterns in relation to the sediment charge; Box plot analysis proved to be pertinently useful for evaluating and interpreting the results in an integrated manner, mainly due to the large number of parameters analyzed; The dredging works had a balanced management between the amount of dredged sediments and their spatial disposition at the discard site when compared to the dredging area.