Year: 2025
Type: article
Abstract: Dredging of fine sediments and dumping of fines at disposal sites produce passive plumes behind the dredging equipment. Each type of dredging method has its own plume characteristics. All types of dredging operations create some form of turbidity (spillage of dredged materials) in the water column, depending on: i) applied method (mechanical grab/backhoe, hydraulic suction dredging with/without overflow); ii) nature of the sediment bed and iii) hydrodynamic conditions. A simple parameter to represent the spillage of dredged materials is the spill percentage (Rspill) of the initial load. In the case of cutter dredging and hopper dredging without overflow, the sediment spillage is mostly low with values in the range of 1% to 3%, The spill percentage is higher in the range of 3% to 30% for hopper dredging of mud with intensive overflow. Spilling of dredged materials also occurs at disposal sites. The spill percentage is generally low with values in the range of 1% to 3% if the load is dumped through bottom doors in deep water creating a dynamic plume which descends rapidly to the bottom with cloud velocities of 1 m/s. The most accurate approach to study passive plume behaviour is the application of a 3D-model, which however is a major, time-consuming effort. A practical 1D-plume dispersion model can help to identify the best parameter settings involved and to do quick scan studies. The proposed 1D-model represents equations for dynamic plume behaviour as well as passive plume behaviour including advection, diffusion and settling processes.
DOI: 10.3390/jmse13061186
Author: Leo van Rijn
Language: English
Subfield: Earth-Surface Processes
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W4411421089