Hydrodynamic and salinity modeling in Gorgan Gulf for the retrieval of the confidence interval between aquaculture fields under instantaneous pollution loading

One of the important issues in aquaculture is the confidence interval between the aquaculture fields under the different pollution loading conditions. one of these conditions is the instantaneous pollution loading. It is necessary to determine a confidence interval between aquaculture fields that the instantaneous pollution in one field doesn’t influence another field. Gorgan Gulf is one of the most important water resources and supplier of fishing in Iran. The goal of this study is the determination of confidence interval between aquaculture fields. In this study، 2-D hydrodynamic and salinity modeling of Gorgan Gulf using MIKE21 is performed. Salinity concentration was measured in 19 different stations during 5 months of 1390 and the hydrodynamic and salinity models were calibrated and verified using these data. The optimum values for manning and dispersion coefficients were determined 0. 025 m/s and 50 m2/s، respectively. Then، 6 different conservative instantaneous pollution point sources were exerted in the gulf and the salinity model was implemented. The peak of pollutant concentration in various distances from point sources was determined and compared with the initial concentration of pollutant in the point sources. The results demonstrated that 99. 9% of pollutants is diluted until to 100m from point sources. Hence، the confidence interval of Gorgan Gulf was determined about 100m.