earticle

영어

In order to identify the environmental factors that cause the dysoxic water, the water temperature difference(del_temp), salinity difference(del_sal), density difference(del_rho), Brunt-Väisälä frequency(bvf), Richardson Number(ri_num) Logistic regression analysis was performed on the six explanatory variables of difference(del_z). Mcfadden R ^ 2 of the regression model was 0.7422 and the explanatory power of the model was good. According to ANOVA analysis, the temperature difference, stratigraphy stability(bvf) and Richardson number were significant in the generation of dysoxic water, and salinity difference was not significant. In particular, the p-value for the temperature difference was 2.2 * 10 ^-16, close to zero. Therefore, it was found that the water temperature difference between the surface layer and the bottom layer is the most influential factor in the occurrence of dysoxic water in Dangdong Bay. As a result of estimating the probability of occurrence of dysoxic water by using the depth difference and water temperature difference among the above six explanatory variables, the probability of occurrence of dysoxic water is 70% when water depths are 5m, 10m, 15m and 20m, The temperature differences were about 8℃, 6℃, 5℃ and 3℃, respectively.