Modelling of Dredged Material Disposal: Mersin Bay Case Study

2015-10-10
Sadighrad, Ehsan
Tuğrul, Süleyman
Salihoğlu, Barış
Management of disposal of solid materials dredged from harbours, shipping channels and coastal environments for different purposes is essential for sustainable land/marine ecosystems, keeping economic values and human quality of life along coastal areas. Therefore, comprehensive and detailed investigations of geo-chemical properties of organic/inorganic pollutants in dredged materials and principal physical and bio-geo-chemical properties of the selected disposal sites are commonly a prerequisite for any planned dredging activity. These appropriate control measures should be taken to avoid or reduce unwanted impacts of dredged materials at dumping sites and to meet specific environmental objectives. This study focuses on major physical factors/processes (under different current velocity, stratification, barge volume/speed and direction during dumping) that govern the amount of dredged solid materials (sediment in different sizes) that go into suspension and the parameters which affect the short term spreading of sediments dumped into the upper layer (4-10 m depth range) of disposal areas. The STFATE model developed in the USA for this purpose is widely applied by environmental scientists in other seas. We have also adapted this multi-layer model to simulate spreading of sediments (composed of sand, silt, and clay) at disposal point (depth: 50m and 150m) on NE Mediterranean shelf. This model simulates short-term spreading of disposed materials which is divided into three phases; the convective phase which is the time from disposal to the bottom impact, the dynamic collapse which describes how the material spreads at the bottom after impact and the passive diffusion phase which is a long term process and not included in our study. The model results indicate critical roles of ship speed/direction under different current and sediment compositions during the short-period (2-3 hours) from dumping until sedimentation on the bottom. According to the model results, sandy particles sink much faster and reach the bottom in about 5 minutes whilst smaller fractions of sediments spreads over an area of about 7400 m(2) (in 10 m depth below surface) and then dispersed on the bottom of disposal site in 60-120 minutes under changing factors such as current and barge velocities at the time of disposal, and sediment composition. These factors also determine the thickness of disposed materials on the bottom, varying between 25 cm to 2 m depending on barge volume and other physical factors in each disposal. Model results also imply that dumping of non-toxic dredged materials mainly influence bio-optical properties of merely upper layer waters and benthic fauna of disposal site selected on the shelf having low biomass and fisheries.

Suggestions

Modelling of Dredged materal disposal Mersin Bay Case Study
Sadighrad, Ehsan; Tuğrul, Süleyman; Salihoğlu, Barış (null; 2015-10-10)
Management of disposal of solid materials dredged from harbours, shipping channels and coastal environments for different purposes is essential for sustainable land/marine ecosystems, keeping economic values and human quality of life along coastal areas. Therefore, comprehensive and detailed investigations of geo-chemical properties of organic/inorganic pollutants in dredged materials and principal physical and bio-geo-chemical properties of the selected disposal sites are commonly a prerequisite for any pl...
Simulation of streamflow using hydrologic modeling system HEC-HMS
Erşahin, Berkan.; Kentel Erdoğan, Elçin; Department of Earth System Science (2020)
Basin models are fundamental for water resources assessment, analyzing quality and quantity of streamflow, managing water distribution systems, protecting and developing groundwater systems, flood protection, and water-supply forecasting. The integration of all hydrologic processes with their interconnections to each other at the basin scale is required for basin models. Mathematical basin models such as HEC-HMS are used for simulating hydrological processes in basin-scale to understand basin response to st...
Modelling and assessment of landfill gas generation at afyonkarahisar landfill site
Karayılan, Sevde; Aksoy, Ayşegül; Department of Environmental Engineering (2018)
Management of municipal solid wastes is one of the important environmental problems because of increasing population and developing industrialization in our country. Besides, there is a need to seek alternative energy sources due to rapid consumption of conventional energy sources. Landfilling is still the most common solid waste disposal method in the world and generated landfill gas consists of significant amount of methane that could be used for energy generation. In this study, it is aimed to model the ...
Modeling of mogan and eymir lakes aquifer system
Yağbasan, Özlem; Yazıcıgil, Hasan; Department of Geological Engineering (2007)
Mogan and Eymir Lakes, located 20 km south of Ankara, are important aesthetic, recreational, and ecological resources. Dikilitaş and İkizce reservoirs, constructed on upstream surface waters, are two man-made structures in the basin encompassing an area of 985 km2. The purpose of this study is (1) to quantify groundwater components in lakes’ budgets, (2) to assess the potential impacts of upstream reservoirs on lake levels, and (3) to determine effects of potential climatic change on lakes and groundwater l...
Application of the bentix index in assessing ecological quality of hard substrata: a case study from the Bosphorus Strait, Turkey
KALKAN, E.; KARHAN, S.U.; MUTLU, E.; SIMBOURA, N.; BEKOLET, M. (National Documentation Centre (EKT), 2007-6-1)
In this paper, a biotic index (Bentix) has been used for the assessment of ecological quality status of shallow water hard substrate benthic ecosystems affected by coastal sewage discharges in the Bosphorus Strait. A significant difference was observed between the control and the discharge stations with regard to Bentix values (Mann-Whitney U Test, p=0.002) and ecological quality status of the discharge stations was worse than that of controls. The index values revealed that sewage discharges caused ser...
Citation Formats
E. Sadighrad, S. Tuğrul, and B. Salihoğlu, “Modelling of Dredged Material Disposal: Mersin Bay Case Study,” 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56084.