Engineering Tools for the Estimation of Dredging-Induced Sediment Resuspension and Coastal Environmental Management

Abstract

In recent years, increasing attention has been paid to environmental impacts that may re‐ sult from resuspension, sedimentation and increase in concentration of chemicals during dredging activities. Dredging dislodges and resuspends bottom sediments that are not captured by dredge-head movements. Resuspended sediments are advected far from the dredging site as a dredging plume and the increase in the suspended solid concentration (SSC) can strongly differ, in time and space, depending on site and operational condi‐ tions. Well-established international guidelines often include numerical modelling appli‐ cations to support environmental studies related to dredging activities. Despite the attention that has been focused on this issue, there is a lack of verified predictive techni‐ ques of plume dynamics at progressive distances from the different dredging sources, as a function of the employed dredging techniques and work programs, i.e., spatial and temporal variation of resuspension source. This chapter illustrates predictive techniques to estimate the SSC arising from dredges with different mechanisms of sediment release and to assess the spatial and temporal variability of the resulting plume in estuarine and coastal areas. Predictive tools are aimed to support technical choices during planning and operational phases and to better plan the location and frequency of environmental moni‐ toring activities during dredging execution.