Dredging

About: Dredging is a research topic. Over the lifetime, 3300 publications have been published within this topic receiving 28325 citations.

Land making method using water way,harbour district dredge soil

Abstract: A technology for building artificial land includes pumping the sludge generated by dredging the navigation channel or harbour in mixing pool, adding coagulant, stirring, pumping in deposition pool, depositing, removing water layer, and naturally drying the earth layer for 2-3 years.

Dredge Disposal Study. San Francisco Bay and Estuary. Main Report.

Abstract: : The report presents the results of a five year, interdisciplinary study of the impacts associated with dredging operations with open water disposal in San Francisco Bay and the ocean and evaluates alternative disposal methods including land disposal and marsh development. (Author)

Hydrodynamics of a small trained tidal inlet (Currumbin Creek, Australia)

Abstract: . Small tidal inlets are important features of coastal areas, in terms of provision of access from a back barrier water-body to the ocean as well as periodic circulation of fresh nutrients for the local ecology. Usually, dimensional and geometrical characteristics contribute significantly to morphological stability or instability of a particular inlet and necessitate an individual investigation of any desired location. In other words, generalized usage of previous empirical and experimental research of a different position can hardly be used for other places. In this regard, one of the powerful tools to understand the physical processes of a particular region is to collect as much field data as possible. Such a dataset is used to further analyse and explore the governing processes and can also be used for building a numerical computer model for supplementary studies. In this research, the results of a comprehensive field measurement at Currumbin Creek, Queensland, Australia are presented. This study is part of broader research to investigate the long term evolution of the Currumbin entrance and its adjacent beaches. Currently, an annual dredging campaign is needed to reduce the risk of flooding due to excess rainfall inundations and to maintain water quality. The majority of data were collected over a three month period consistent with the time of the 2012 dredging operation. However, due to the loss of some instrumentation, data collection for some of the parameters was repeated till the middle of May 2013. All collected data included: (1) nearshore waves and tide; (2) creek tidal variation; (3) creek flow discharge and velocity; (4) bathymetric survey of the creek; (5) beach profile evolution survey; and (6) sediment sampling. The measurement showed that the creek entrance is tidally dominated, with flood events having a major role in sediment transport into the creek. The nearshore stations' wave data illustrated the marginal effect of the beach curvature between updrift and downdrift stations. Thus, the historical dataset available from the updrift wave rider buoy will be selected to be used for future numerical modelling. Although changes of some beach profiles were comparatively insignificant, the dramatic changes of the profile lines nearby the inlet channel and also rapid bathymetric change of the flood shoal following the dredging completion are valuable information to better calibrate and interpret a local sediment modelling study for the next phase. Essentially, this evaluation needs to be considered for proposing any alternative maintenance activities.

Maintenance dredging at Port of Townsville

Abstract: The Port of Townsville conducts regular annual maintenance dredging to maintain depths of its harbor basin and approach channels for the navigational safety of the vessels against the natural accumulation of marine sediments. In addition to the regular maintenance dredging, the port undertakes emergency dredging in cases where large quantities of sediments are mobilized and deposited in port waters by cyclone or major flood events. The maintenance dredging material derived from the port may be disposed at sea or on land in accordance with relevant state and commonwealth regulations. For the land disposal, the dredged mud slurry is hydraulically placed into containment ponds and left to undergo sedimentation and self-weight consolidation to form fill material for land reclamation. This paper provides an overview of the maintenance dredging at the Port of Townsville and emphasis on maintenance dredging requirements, sediment quality, bathymetry, dredging methods used, and dredged material disposal options.

Avaliação do impacto da dragagem sobre associação fitoplanctônica do porto de aratu, baía de todos os santos, bahia

Abstract: In the area of influence of dredging to deepen the Aratu harbor, in All Saints Bay, the pattern of the structure of phytoplankton association (composition, richness, relative abundance, frequency and density), oceanographic structure (temperature and salinity), nutrient (phosphorus and nitrogen) and quality water quality (pH and dissolved oxygen) and trace-elements were used aiming at a comparative interpretation of the effects of dredging, which would be used to assess the environmental recovery of the pelagic ecosystem. There were two campaigns in February (late dry season) and September (end of rainy season), in ebb and flood. We identified 50 species, before the dredging process and 40 species during dredging, the Bacillariophyta were the representatives with the highest relative abundance and richness compared to other groups of microalgae. This study indicated a decrease of species richness and density increase during the dredging. The composition of phytoplankton association reflected the observed temporal variability in oceanographic characteristics of the water caused by the gradient of rainfall and water quality probably due to the dredging activity and a clear separation between the phase of dredging (dry season) and phase Pre-dredging (rainy season).