• 환경영향평가
• /
• 제18권3호
• /
• pp.185-193
• /
• 2009

This study documented and diagnosed the status and problems of coastal dredging and offshore disposal of dredged sediments in South Korea to improve assessment procedures for marine environmental impacts and develop effective management systems. A total of $729({\times}10^6)m^3$ of coastal sediment was dredged in the harbors during the period of 2001-2008. Most of dredged sediment was disposed to the land dumping sites whereas ocean disposal accounted for less than 5%. Ocean disposal areas were especially concentrated to the exclusive economic zone (EEZ) in the southeast of Busan, which is not only an important fishing area for fishermen, but also considered to be spawning and nursery ground for some commercial fish species. To minimize negative impacts of dredging and ocean disposal of coastal sediment on marine ecosystem and potential strife among coastal users, we suggest 1) in development projects involving ocean disposal, it should be mandatory to propose careful reuse plans in the land, and 2) guidelines of environmental assessment and consequence management programs should be developed and implemented.

• 환경영향평가
• /
• 제18권3호
• /
• pp.131-141
• /
• 2009

We studied improvement in marine environmental impact assessment and related management systems of coastal sediments that are dredged inshore but disposed offshore. After reviewing and diagnosing the existing assessment procedures and problems, we recommend to design the core assessment items and improve the reliability of assessment byenhancing the quality assurance/quality control (QA/QC) and verification processes. We proposed eco-friendly disposal plan for dredging sediment such as reuse system in land development was explored. A marine environmental database system was established to support the assessment processes. Guidelines for marine research and modelling were proposed for improving assessment of dredging and disposal of coastal sediment. Also, applying of screening and scoping for marine environmental assessment was reviewed.

• 환경영향평가
• /
• 제24권5호
• /
• pp.444-455
• /
• 2015

연안준설행위에 따른 연안준설토의 활용 및 처분에 관련된 현 체계 및 법적 기준의 고찰을 통해서 문제점을 진단하고 개선방안을 제시하고자 하였다. 현행 제도상 연안준설토는 활용과 처분의 기준을 준설토사유효활용기준에 따라 구분하고 있으나 매립이 완료된 투기장을 부지로써 활용함으로서 처분과 활용의 개념이 모호하다. 또한 준설토의 매립재활용에 있어서 토양오염우려기준을 적용하는 것은 연안준설토의 토양특성, 기준항목의 차이, 실험방법의 차이 등을 고려해볼 때 적합하지 않은 것으로 판단된다. 하지만 현행의 유효활용기준은 매립재 활용에 있어 문제점이 있으므로 다음과 같이 개선이 요구된다. 첫째, 매립재 활용을 위한 용도구분이 필요하며, 둘째, 인체위해성을 고려한 2단계 체계의 기준농도를 제시할 필요가 있다. 또한 해역이용협의과정에서 연안준설토를 투기장에 투기시 주변해역에 미치는 영향파악과 저감대책을 포함한 평가가 이루어져야 할 것이다.

• 한국항만학회지
• /
• 제11권2호
• /
• pp.203-214
• /
• 1997

Hydraulic dredgers(Hopper dredger) are the most important piece of equipment in the entire harbor engineering field, and most suitable for the removal of sand and weakly consloidated sediment such as silt. In maintenance dredging, specially confined harbor or congested passage area, Hopper dredger is user most popularly because less obstruction and danger to navigation than other mostly stationary dredgers. Investigation of the physical behave of dredged material disposal in coastal water from the Hopper dredger includes estimations of pattern as well as thickness of material on the bottom. Calculation based on vertical settling and horizontal advection of single particles ignore the effects of bulk properties of the disposed marterial, vertical and horizontal diffusion. and material dilution due to the entrainment of ambient water during descent. This paper focuses on the analysis of dredging and dumping characteristics and the spatial and temporal changes in the dumping fields for the water column and bottom at a hypothetically confined coastal water. This model accounts the behavior of material after release from the hopper dredger. It is shown that the model describes the qualitative feature of prototype dumping process and its response.

• 한국농공학회논문집
• /
• 제60권4호
• /
• pp.83-91
• /
• 2018

Land reclamation, coastal construction, coastline extension and port construction, all of which involve dredging, are increasingly required to meet the growing economic and societal demands in the coastal zone. During the land reclamation, a portion of landfills are lost from the desired location due to a variety of causes, and therefore prediction of sediment transport is very important for economical and efficient land reclamation management. In this study, laboratory disposal tests were performed using an open channel, and suspended sediment transport was analyzed according to flow velocity and grain size. The relationships between the average and standard deviation of the deposition distance and the flow velocity were almost linear, and the relationships between the average and standard deviation of deposition distance and the grain size were found to have high non-linearity in the form of power law. The deposition distribution of sediments was demonstrated to have log-normal distributions regardless of the flow velocity. Based on the experimental results, modeling of suspended sediment transport was performed using deep neural network, one of deep learning techniques, and the deposition distribution was reproduced through log-normal distribution.

• 해양환경안전학회지
• /
• 제15권4호
• /
• pp.345-354
• /
• 2009

해역이용협의에 따른 협의서 검토현황과 연안이용형태를 분석한 결과, 공유수면 점 사용은 공작물설치와 해수 취배수, 공유수면 매립은 산업단지조성, 항만 어항개발과 도로건설의 점유율이 높았고, 점 사용은 서해에서 그리고 매립은 남해에서 우세하였다. 지역별로는 전남, 경남지역과 인천 경기지역에서 이용행위가 많았다. 해역이용협의 검토량은 2008년이 전년도에 비해 약 200건 이상 증가하였고, 협의과정에서 준설토 해양투기, 매립, 준설, 해수 취배수, 바다골재채취와 규사채취에 대해 보완요청이 주로 이루어졌다. 연안이용은 대부분 해양환경기준 I등급 또는 II등급의 지역에서 집중되었고, 특히, 법령상 해양 규제지역인 특별관리해역에서는 항만 어항개발과 관련된 매립과 공작물설치, 국립공원에서는 공작물설치와 호안정비가 많았다. 또한, 수산자원보호구역에서는 호안정비, 공작물설치와 해수의 취배수 행위가 많이 이루어진 것으로 평가되었다. 해역이용협의제도의 제반적인 합리성과 신뢰성을 높이는 방법 등 개선방안을 제도운영 및 정책적인 측면과 협의서 작성과 관련한 해양환경영향평가 측면으로 구분해서 정책제언을 제시하였다.

• 환경영향평가
• /
• 제25권6호
• /
• pp.466-476
• /
• 2016

준설은 수저퇴적물을 관리하는 데에 있어 유용한 공법 중 하나로 수심유지, 수환경관리 등 다양한 목적으로 사용되며 준설사업에서 발생되는 수저준설물질(주로 토사 성분)은 임의로 폐기물로 간주되어 폐기물 배출해역에 투기되어왔다. 그러나 준설물질은 여러 목적의 토목사업의 재료로 사용할 수 있기 때문에 준설물질을 자원화할 수 있도록 제도적으로 보장해 줄 필요성이 대두되고 있다. 최근 퇴적물을 평가하는 데에 있어 기존의 오염물질 함량 기준이 생물 영향과 직접 연관되지 않는 한계를 극복하기 위해 생체지표 연구가 수행되고 있다. 생체지표는 오염물질의 노출과 영향을 진단하는 지표로서 다양한 연구에 유용하게 사용될 수 있다. 본 논문에서는 퇴적물의 위해성 평가에 있어 생체지표를 활용하는 것이 가지는 장점을 보여주고 생체지표를 활용한 해양퇴적물의 오염 및 건강성 그리고 준설물질의 처리와 유효활용을 위한 의사결정에 있어 그 유용성을 보여주고자 한다.

• 한국수산과학회지
• /
• 제37권5호
• /
• pp.423-432
• /
• 2004

In coastal area of Inchon, dredging and the disposal of dredged material for sea-wall construction and reclamation have increased in recent years. These activities may impact the benthic environment and result in changes in benthic communities, but little information is available on the extent and direction of these changes. We investigated whether there have been changes in the dominant macrobenthic species and benthic community over the last decade, and explored the relationship between environmental variables and spatial patterns of macrobenthic community structure. We sampled macrobenthos and recorded environmental variables in the coastal habitats of Inchon in March and June 2004. In total, 212 macrobenthic species were recorded during this study, predominately crustaceans $(34{\%})$, mollusks $(32{\%})$ and polychaetes $(21{\%})$. The mean density of macrobenthos was $1,393\;ind./m^{2}$.The most abundant species was Amphioplus japonicus $(20.5{\%})$, followed by Heteromastus filiformis $(14.4{\%})$, Theora fragilis $(8.2{\%})$ and Ampharete sp. $(4.0{\%})$. Over the past decade the dominant macrobenthic species in this area shifted. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among three regions: the middle part of the sampling area (B), site 8 (C) and other sites (A). Mean density varied significantly among the three regions, but no differences in the number of species and diversity (H') were observed. The distribution of the macrobenthic community was affected by environmental variables such as percentage sand content and sediment kurtosis. Species that were important in different areas included A. japonicus in region A, Raeta puchella in region B and T. fragilis in region C. The important species in regions B and C were filter-feeding bivalves, and the abundance of these species may be related to the increase in percentage sand content. We suggest that the sediment composition (percentage sand content) may be an important factor in determining the dominant species and structure of the macrobenthic communities in coastal Inchon. Long-term monitoring programs are necessary to understand ongoing changes in the benthic communities of this area.