Ecological modeling for the prediction and management of water quality in coastal seas of Korea

To aid in effectively managing the water quality of coastal areas, we used an eco-hydrodynamic model to predict summer water quality and to estimate the reduction in pollutant loads required to recover water quality. Under current environmental conditions, chemical oxygen demand (COD) exceeded seawater quality criteria, and water conditions were eutrophic. When we reduced the terrestrial COD, nitrogen, and phosphorus loads by 90%, the water quality criteria of Region A (Chinhae Bay) were not satisfied. However, when the nutrient loads from sediment and land were each reduced by 70% simultaneously, COD and Chl-α were recovered. When we reduced the input COD and nutrient loads from the Nakdong River by 80%, Chl-α and COD of Region B (Estuary of the Nakdong River) decreased below 10 ㎍ 1?¹ and 2 ㎎ 1?¹, respectively. The water quality criteria of Region C (Coastal sea of Busan) were satisfied when we reduced the terrestrial COD and nutrient loads by 70%. To achieve the reduction in pollutant loads, sustainable countermeasures, which include the expansion of sewage and wastewater facilities, sediment control, and limited land use, are necessary.