Modeling study of dredging induced sediment plume transport in Hamilton Harbour

To assess and predict the direction and range of a dredging induced contaminated sediment plume on the surrounding environment, a three-dimensional hydrodynamic and mud transport modeling system MIKE 3-FM was used in the Randle Reef area of Hamilton Harbour. Simulations were carried out with the typical local and maximum winds under which the dredging operation would proceed. The dredge plume travel pattern and range in both horizontal and vertical planes are examined under various wind conditions and model mesh resolutions. It was found that the simulated plume extents were very sensitive to transport model mesh resolution due to the additional numerical advection induced in the calculations. Detailed discussion of this particular issue has not been observed in other publications. The results of this simulation provide useful information for remediation project managers in planning and guiding the environmental monitoring of dredging operations. In addition, the methodology used in this study can be adapted to other dredging projects. Key words: contaminated sediment plume, water quality monitoring, sediment remediation, Randle Reef, hydrodynamic and transport modeling. Afin d'evaluer et de prevoir la direction et l'etendue d'un panache de sediments contamines cause par le dragage dans le milieu environnant, un systeme de modelisation tridimensionnelle hydrodynamique et de transport de boue MIKE 3-FM a ete utilise dans la region du recif Randle du port de Hamilton. Des simulations ont ete effectuees avec les vents locaux et maximaux typiques sous lesquels l'operation de dragage devait se derouler. La trajectoire et l'etendue du panache de dragage dans les plans horizontal et vertical sont examinees dans diverses conditions de vent et dans diverses resolutions de maillage. Il a ete constate que les etendues simulees du panache etaient tres sensibles a la resolution du maillage du modele de transport en raison de l'advection numerique supplementaire induite dans les calculs. On n'a pas observe de discussion detaillee sur cette question particuliere dans d'autres publications. Les resultats de cette simulation donnent aux gestionnaires de projet de restauration des renseignements utiles quant a la planification et l'orientation de la surveillance environnementale des operations de dragage. De plus, la methodologie utilisee dans cette etude peut etre adaptee a d'autres projets de dragage. [Traduit par la Redaction] Mots-cles : panache de sediments contamines, surveillance de la qualite de l'eau, assainissement des sediments, recif Randle, modelisation hydrodynamique et de transport.
Introduction During dredging, suspended sediment plumes are generated and can potentially spread over a large area. Therefore, it is important to understand these ranges are under different operation conditions. In [...]