Professor, Faculty of civil engineering, architecture and geodesy, University of Split, Croatia

Speech Title: How Results for the Dispersion of Contaminants in Environmental Flows Can Be Used in Assessing a Dilution Process in River Plumes in Estuaries

Abstract: River plumes discharge a large amount of inland materials into ecologically sensitive coastal waters through physical processes that transports buoyant freshwater close to the river mouth and impacting the marine ecosystem. These environmental flows are multi-scale flow structures in a turbulent state of motion, unsteady and spatially inhomogeneous, playing dominant role during the mixing and dilution of contaminants. We present the probabilistic model of the near-field dispersion of contaminants in a surface layer of an estuary based on spatially integrated concentration statistics as a simple alternative to the point concentration probability density function. A methodology quantifying the degree of dilution within the upper layer of river plumes, under stratified condition, could be used for assessing the marine ecosystem impact from different catchment loadings and guide future efforts for monitoring potential eutrophication hot-spots in the coastal area. A dilution measure is presented as a combination of expected mass and volume fraction, indicating area where dilution process will attenuate the concentration of a passive contaminant below any selected environmental limits. The theoretical prediction is experimentally validated using the salinity dilution as an inverse process in the actual filed case.