해양준설토를 이용한 연안생태환경공간의 환경성 평가에 관한 연구

Abstract

The ecological environmental zones in coastal area, like tidal flat and salt marsh, were gradually decreased due to large scale of coastal development projects, reclamation and so on. Therefore, the development of artificial tidal flat and salt marsh has been emphasized in coastal area as mitigation concept. Also, dredged soil, was occurred by coastal developments, carried coastal pollution. So, recycle technique of dredged soil is badly needed to reduce this problems. As united solution to solve these problems, This paper proposes a creation of ecological environmental zones in coastal sea by using dredged soil. To select optimum site for creation of in-situ pilot plant, it was conducted coastal environmental, physical oceanographic environmental and topographical change surveys in the Nakdong estuary, Korea and documentary survey about there. As results of surveys, Jinudo, which located in western part of Nakdong estuary, was selected as optimum site for in-situ pilot plant. Therefore, in-situ pilot plant of tidal flat and salt marsh, which was distinguished by content of dredged soil as design factor, was created in Jinudo. In this paper, as a fundamental study for environmental assessment on the creation of ecological environmental zones in coastal sea, it was conducted that the monitoring and experiment for biochemical factors(bio-diversity, population and biomass of macro-benthos, survival ratio of reed, the number of heterotrophic bacteria and physico-chemical characteristics such as COD, IL, TN, TP and pH) as environmental factor. From results of this studies, the restoration index(RI), for evaluation concerning degree of restoration, was proposed and quantitative evaluation was performed using RI. Also, improved restoration index(RI*), which was considered weighted value about design and environmental factors, was suggested and calculated by virtual scenario analysis. As results of these, in Zone.P1, values of RI were relatively similar to each sites. But that of Zone.P2 were clearly classified according to content of dredged soil. And case which has high content of dredged soil has lower RI than other cases. These results were deemed because of difference in characters of dredged soil for creation of in-situ pilot plant. Also, it was proved that weighted value about design factor was main variation factor concerning sum of RI*. It was considered that the methods to select optimum site was helpful and suggested RI and RI* can be applied as criterion to estimate degree of restoration on the creation of ecological environmental zones in coastal area.