TITLE:
Mixing Characteristics under Tide, Meteorological and Oceanographic Conditions in the Euboean Gulf Greece
AUTHORS:
Evangelos Tsirogiannis, Panagiotis Angelidis, Nikolaos Kotsovinos
KEYWORDS:
Sewage Mixing, Water Age, Tide, Gulf of Evoikos, Greece
JOURNAL NAME:
Computational Water, Energy, and Environmental Engineering,
Vol.8 No.4,
October
23,
2019
ABSTRACT: The mixing characteristics in the marine environment of the Euboean Gulf
are studied. The Estuarine and Lake CΟmputer Model three-dimensional
hydrodynamic model has been used, to simulate numerically the effects of the
strong tide conditions, the atmospheric forcing, and the oceanographic conditions. Water age was calculated in
all computational cells and its renewal was
examined with the “pure” water of the open sea
both on the surface layers, where the effect of tide and wind was
pronounced, as well as on the deeper layers and bottom. It was investigated if
in surface layers the tide and the wind restore the water of the study area,
thus preventing its renewal. In the remote area, the mixing and dilution of the
pollutants contained in the treated municipal waste of five installed diffusers
in this complex hydrodynamic field, generated by the aforementioned loads, is
simulated. It was found that even a slight stratification density has the
effect of restricting the vertical mixing and entrapment of dirt in the deeper
layers. The combined impact of municipal
waste effluents on selected areas of high economic, tourist and
environmental value in the Euboean Gulf was assessed. It was found out, that
the Diffuser 2 has a great effect in all the five selected areas, because it
has greater waste water discharge and because of the tide, who produce a
velocity field and transfer the pollutants in longer distances. It was also
investigated indicatively in an important area, whether the presence of tide
contributes to better mixing and dispersing of pollutants and to better water
quality or, on the contrary, as it restores remote pollutants that were
released earlier.