The mathematical model intended for the prediction of suspended solids dispersion in sea offshore area is described. Suspended solids are largely provided by human activities such as dredging or discharges of cuttings from offshore drilling platform. Some results of calculations are also presented.
According to the requirements of environmental protection normative documents, at the preliminary stage of scheduling work on a marine shelf it is necessary to carry out Environment Impact Assessment (EIA) of the planning activity. To obtain such assessment, it is primarily required to reveal the dispersion quantitative dependences on the different polluting substances in the marine environment. In this article, the mathematical model designed for the forecast of the dispersion of suspended solids (SS) in the sea coastal area is described. The source of SS, for example, can be disposals from marine drilling platforms or dredging operations.
When describing the distribution of SS it is possible to outline two qualitatively different areas: a near field region, which sizes correlate with the size of the polluting object (discharge outlet from offshore platform, the equipment used for dredging, etc.), and a far field region to which, as a rule, belongs the control point area. In the near field region close to the discharge outlet, the concentrations of SS are great, and simulation of dispersion demands the detailed information on the equipment in use and as a rule represents rather a difficult task. In the far field region SS behavior is simulated by representing the disposal waste as a series of convecting clouds. Each cloud is characterized by its size, density, location, and the types and concentrations of solids contained within the cloud, that are assumed to have a Gaussian distribution.