광양만과 진주만의 계절별 해수교환율 및 체류시간 특성

Characteristics of Seasonal Sea Exchange Rate and Residence Time in the Gwangyang Bay and the Jinju Bay

At the center of the Noryang waterway, there is the Gwangyang Bay, the Yeosu Strait is located at the west, and the Jinju Bay, the Gangjin Bay and the Sacheon Bay is located at the east. The freshwater from several rivers is coming into the study area. Especially in the event of flood, the freshwater of the Seomjingang is flowing into the Gwangyang Bay area (including the Yeosu Strait) and freshwater of the Gahwacheon (discharge of Namgang Dam) is flowing into the Jinju Bay area (including the Gangjin Bay and the Sacheon Bay) in great quantities. The Gwangyang Bay area and the Jinju Bay area are connected with the Noryang waterway. In addition, the freshwater out of the Seomjingang and the Gahwacheon also affect through the Noryang waterway. In this study, we elucidated the characteristics of seawater exchange rate and residence time seasonally, with a consideration of the freshwater out of 51 rivers, including the Seomjingang and the Gaghwacheon, using a particle tracking method. The result showed that the particles released from the Gwangyang Bay area moved to the Jinju Bay area through the Noryang waterway. However, the particles moved from Jinju Bay area to Gwangyang Bay area appeared comparatively small. Seasonal seawater exchange rate ranged from 41.2 to 51.3% for the Gwangyang Bay area and from 58.0 to 62.1% for the Jinju Bay area. In addition, seawater exchange rates in summer turned out to be larger than those in any other season. The residence time appeared to be 13.3 to 14.7 days in the Gwangyang Bay area and 9.2 to 10.1 days in the Jinju Bay area. As a result, residence time of the Jinju Bay area turned out to be a little bit smaller than those of the Gwangyang Bay area.