· · · Repository Hydraulic Engineering Reports

In January 2002 HR Wallingford published the results of work undertaken on behalf of P&O Ports Limited and the Port of London Authority to investigate the effects of dispersion of fine material arising from dredging and reclamation activities associated with the proposed London Gateway Port (Reference 1). Further plume modelling results, produced for P&O Ports Limited, were published in March 2003 (References 2 and 3). As an aid to understanding the sensitivity of the plume model used for these studies a series of sensitivity tests were undertaken. These sensitivity analysis tests have not been previously published and a selection of test results are presented in this report to provide additional confidence in the results published in References 1, 2 and 3.

In 2001 a DIOC-project was started at Delft University of Technology on the dispersion of fines during sand mining. In this project the behaviour and spreading of fines, which are released through the overflow of a dredging ship, is studied. Laboratory and field studies will be carried out to determine the behaviour and spreading of the fines. However, before any experiments are carried out, a literature study is done to determine the main focus of the subsequent research. This literature study is presented herein. It discusses the whole cycle of dredging, the release of sediment in the water, behaviour of sediment in the water column, sedimentation, erosion and impact on ecology. In the end it is decided that the subsequent research shall focus on two subjects, namely the hindered settling of sand/mud mixtures and the sea/bed interaction.