해수유동 및 부유사 확산의 예측기법 개선에 관한 연구

Abstract

Studies on Improvement of Costal Flow and Suspended Solid Predictions in the Coastal Zone Developments In order to direct the reasonable preparation of Environmental Impact Assessment(EIA) reports and eco-friendly development of projects which give impacts on coastal zone, we found problems on the impact prediction of coastal flow and suspended solids(SS) based on existing EIA reports and suggested the guidelines for the reasonable improvement for the problems through qualitative experiences, quantitative modeling, and foreign case study. The content of the present study includes 1) investigation of coastal flow and SS phenomena, 2) analysis of status and problem for the existing ocean-related EIA, 3) foreign case study such as USA and Japan, and 4) improvement direction of coastal flow and SS predictions in EIA process. The dynamics of coastal processes include coastal flow regimes, weather system, sedimentation transport as well as hydrological link between coast and its boundary. The processes in the coastal zone link all factors physically and biogeochemically, and thus influence the ecosystem in the area. The major flows involved into the processes are tidal flow, wind-driven, density-driven, and wave-driven currents, which influence the biogeochemical system of coastal zone through advection and diffusion processes. Previous fifteen Environmental Impact Assessment reports, mainly for the harbor development, are selected with regional consideration along the coast of Korea and analysed for prediction processes on coastal flow and suspended solid(SS), We found the significant lack of site observation and model verification in the impact predictions of coastal flow, lowering overall confidence level of the previous EIA reports for ocean-related projects. The only tidal flows have been mainly considered in previous EIA but with rare verification through flow observation. The consideration of the non-tidal components in the coastal flow mentioned above are required due to its dynamical characteristics (coastally trapped and non-peridiocal ones compared to tidal flow) and relative density of energy spectra. In the present study, the importance of the non-tidal component in the coastal flow are shown in terms of previous experience and study, numerical modeling, and foreign case study. We suggest the EIA in the ocean-related projects requires to consider flows due to wind, wave, density and offshore current through comprehensive spatio-temporal observations and then verification processes. However, the reasonable prediction of coastal flow through comprehensive observation entails realistic difficulties for separate EIA project due to the vulnerable system of current EIA such as poor EIA cost, lack of specialist, difficulty of ocean observation, and so on. Thus it is suggested that national efforts be also needed to accumulate coastal information such as flow data systematically and thus provide a variety demand including EIA community. The national efforts corresponding effectively to the demand of coastal information in Korea includes the compilation of previous coastal information along the Korean coasts, periodic observation and monitoring of coastal ocean including weather system which drives coastal ocean, real-time coastal reproduction and forecasting of coastal flow (through data, model, and their assimilation), and formation of integrated organization to deal with the coastal information issues.