Site evaluation for the determination of a dredged sediment disposal area through the application of the Montecarlo method

Abstract

Among some of the main concerns of the ports is the generation and maintenance of the depth of the docking sites, which require dredging operations. The dumping of the removed sediment is not a trivial task, in relation to the effects it may cause to the marine biota. For this reason, locating the dumping site requires avoiding the most biologically active spots. The choice of the optimal site in this situation was converted into a multivariable analysis that was solved using the Montecarlo method, to obtain a more complete answer. In this study, a dredging procedure has been proposed that considers the removal of the sediment by means of an excavator and the offshore dumping using one or two hoppers, depending on the case analyzed. This problem was solved in three ports in the Region of Valparaíso in Chile, namely, port of Ventanas, Valparaíso and San Antonio, which allowed the evaluation of the results for diverse spatial features. The results of this study determined that the application of an additional hopper allows to reduce the risk in the procedure in a relevant magnitude. On the other hand, due to the spatial variability of the biological activity, the selection of the dumping point was simpler, reducing the uncertainty of the procedure, as estimated for the port of San Antonio.