산샤댐 건설로 인한 북부동중국해 해양환경 영향 연구 소개

Abstract

The Three Gorges Dam (TGD) as the world’'s largest hydroelectric dam, located at the Three Gorges in the middle of the Changjiang River, have been constructed for primarily preventing flooding downstream until 2009. The Changjiang River contributes about 80% of the total freshwater discharge from rivers supplying into the Yellow and East China Seas. Changiang Diluted Water (CDW) is a mixture of Changjiang freshwater with seawater, and is transported into the South Sea and the East Sea of Korea through the northern East China Sea (ECS). CDW is one of the most important sources of nutrients for marine ecosystem in the ECS. By controlling water flow through the TGD, some fresh water will be prevented from flowing into the ECS , affecting the surrounding ocean environments and their ecosystems. After the completion of the TGD, the variation of the Changjiang River discharge will be changed the oceanographic environments in the adjacent seas. The purpose of the study is to understand long-term variations and to help predict future changes in the marine environments and ecosystems of the East China Sea. We examined the water mass properties of the CDW, the distribution of nutrients and suspended sediments, the effect on the lower trophic ecosystem, and the implications for ocean circulation modeling for the CDW. Water mass structures in the northern ECS show strongly influenced by the high temperature and low salinity of the CDW. The concentrations of nitrate and phosphate in the CDW are characterized by relatively high, but silicate is low due to probably the construction of TGD. Data presented in this study can be used to national marine policies related to the predicted effects of the TGD.