• 한국해양학회지:바다
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• 제18권4호
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• pp.214-226
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• 2013

상류지역의 보 건설과 준설작업이 이루어지고 있던 2011년 1월부터 2012년 10월까지 낙동강, 하구 및 연안역에 걸쳐 식물플랑크톤 군집의 변화양상을 이해하고자 14개 정점에서 총 12회의 조사를 실시하였다. 조사시기동안 낙동강 유역의 월 누적 강수량은 0~502mm 이었다. 강유역은 표 저층 모두에서 해수의 영향이 없었고, 하구역 정점에서는 0.1~34.8 psu의 범위로 강우의 영향으로 염분 변동폭이 컸으며, 연안역에서는 홍수기인 7-8월을 제외하고는 대부분 정점에서 30 psu이상의 염분 특성을 보였다. 식물플랑크톤은 총 402종이 분류 동정되었으며 강유역에서는 178종, 하구 및 연안역에서는 331종이 출현하였다. 식물플랑크톤 현존량은 강유역, 하구역, 연안역 순으로 감소하였으며, 2011년에 비해 2012년에 높게 나타났다. 출현빈도와 우점률 측면에서 전체 조사 수역의 상위 20종은 Stephanodiscus spp., Aulacoseira granulata, Aulacoseira var. angustissima, Pseudo-nitzschia spp.의 순었으며, 중요 분류군은 규조류인 것으로 나타났다. 계절별 각각의 정점에서 가장 우점비율이 높았던 종은 2011년(13종)에 비해 2012년(10종)에 다소 단순화되는 경향을 보였다. 식물플랑크톤 종다양성지수는 조사 연도별로는 큰 차이가 없었으나, 강 및 하구에 비해 연안이 다소 높은 것으로 나타났다. 유사도에 의한 군집분석을 이용해 식물플랑크톤의 군집변화를 살펴보면 2011년은 조사시기에 따라 다양한 군집구조가 나타난 반면 2012년은 군집구조의 변화가 크지 않고 단순화 된 것으로 나타났다. 이와 같이 2011년에 비해 전반적으로 높아진 식물플랑크톤의 현존량, 단순화된 우점종의 수 및 군집구조 등은 낙동강 유역의 급격한 환경변화로 인한 것으로 판단된다. 따라서 본 연구에서 다루지 못했던 낙동강-하구-연안의 영양염 분포, 담수유출 및 범위의 변화 등에 따른 식물플랑크톤을 포함한 생물군집의 통합적 분석이 함께 수행되어야 할 것으로 생각된다.

• Parasites, Hosts and Diseases
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• 제34권4호
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• pp.273-278
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• 1996

우리 나라 남해안 일부 지방산 반지락에서 Panpctremc속 흡충의 피낭유충 감염상을 조사하였다. 1990년 9월에 경상남도 5개 지역과 전라남도 8개 지역을 직접 방문하여 현지산 반지락을 구입하여 인공소화법으로 조사한 결과 총 300개의 반지락 중 233개(77.7%)에서 1-273개(평균 54개)의 피낭유충이 검출되었다. 검출한 피낭유충은 V형의 배설낭. 구홉반의 측돌기, 복홉반과 떨어져서 맹장 사이 정중면에 위치한 생식공 등의 형태학적 특징을 토대로 Pqwokemo속으로 동정하였다 경남 사천군 용현면산. 전남 고흥군 도화면산. 장홍군 안량면산, 강진군 칠량면산 반지 락은 1000% 감염되어 있었으며 감염량은 각각 평균 71. 31. 80 및 42개이었다. 경남 남해군 고현면산. 의창군 구산면산 및 전남 고흥군 도화면산 반지락은 조사한 97.5-90.0%가 평균 117개, 28 개 및 76개의 피낭유충에 감염되어 있었다. 경남 남해군 설천면산 전남 여천군 화양면산. 승주군 별량면산 남해군 북평면산 반지락은 조사한 55.0-80.0%가 평균 6-25개의 피낭유충에 감염되어 있었다. 경남 고성군 삼산면산 및 전남 여천군 돌산읍산 반지락에서는 피낭유충이 검출되지 않았다. 이상의 결과로 우리 나라 남해안 일부 지방산 반지락에 Pawatremn속 흩충의 피낭유충이고 도로 감염되어 있음을 확인하였다.

• Geomechanics and Engineering
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• 제17권5호
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• pp.421-427
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• 2019

Coastal erosion is becoming a significant problem in Greece, Bangladesh, and globally. For the prevention and minimization of damage from coastal erosion, combinations of various structures have been used conventionally. However, most of these methods are expensive. Therefore, creating artificial beachrock using local ureolytic bacteria and the MICP (Microbially Induced Carbonate Precipitation) method can be an alternative for coastal erosion protection, as it is a sustainable and eco-friendly biological ground improvement technique. Most research on MICP has been confined to land ureolytic bacteria and limited attention has been paid to coastal ureolytic bacteria for the measurement of urease activity. Subsequently, their various environmental effects have not been investigated. Therefore, for the successful application of MICP to coastal erosion protection, the type of bacteria, bacterial cell concentration, reaction temperature, cell culture duration, carbonate precipitation trend, pH of the media that controls the activity of the urease enzyme, etc., are evaluated. In this study, the effects of temperature, pH, and culture duration, as well as the trend in carbonate precipitation of coastal ureolytic bacteria isolated from two coastal regions in Greece and Bangladesh, were evaluated. The results showed that urease activity of coastal ureolytic bacteria species relies on some environmental parameters that are very important for successful sand solidification. In future, we aim to apply these findings towards the creation of artificial beachrock in combination with a geotextile tube for coastal erosion protection in Mediterranean countries, Bangladesh, and globally, for bio-mediated soil improvement.

• 한국산림과학회지
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• 제8권1호
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• pp.17-20
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• 1968

4개지역(個地域)에서 생육(生育)하고 있는 곰솔의 성장비교(成長比較)을 하였는데 그 결과(結果)는 다음과 같다. (1) 직경성장(直徑成長)이 가장 양호(良好)한 곳은 합천(陜川)이고 다음이 울산(蔚山), 제주(濟州), 수원(水原)의 순위(順位)였다. (2) 수고성장(樹高成長)이 가장 양호(良好)한 순위(順位)을 보면 울산(蔚山), 수원(水原), 합천(陜川), 제주(濟州) 순(順)이다. (3) 재적성장(材積成長)이 가장 양호(良好)한 순위(順位)을 보면 합천(陜川), 울산(蔚山), 제주(濟州), 수원(水原)으로 되어있다. (4) 위의 것으로 미루어 볼 때 곰솔이 해안수종(海岸樹種)으로 알려져 있으나 성장(成長)은 내륙지방(內陸地方)이 도리어 도서지방(島嶼地方) 또는 해안지방(海岸地方)보다 양호(良好)하였다.

• 한국환경과학회지
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• 제10권4호
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• pp.275-280
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• 2001

In an attempt to evaluate the possibility of producing an organic fertilizer using sediments from coastal farming areas, the chemical composition, bacteriological quality and heavy metals in the sediments alkalized by conditions : a 1:4 mixture of dry sediment to food wastes and the addition of 30% quicklime to the mixture. According to the classification standard for compost constituent by Higgins, all composts had a low or intermediate grade in T-N and $K_2O$ content, a low grade in $P_2O_5$ and a high grade in CaO and MgO content. Stabilization by quicklime and magnesium hydroxide is likely to inhibit th bacterial decomposition of organic matter and the actigity of pathogenic organic. Raising the pH of stabilized sediment to 12 for 2 hours(PSRP criteria of EPA) allowed 99.99% of the coliform group, fecal group and viable cell count to be reduced. the results suggested that the crude fertilizer produced by alkaline stabilization method was innoxious and thereby the sediments from coastal farming areas could be used as organic fertilizer.

• Wind and Structures
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• 제21권6호
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• pp.625-639
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• 2015

Monopiles have been most widely used for supporting offshore wind turbines (OWTs) in shallow water areas. However, multi-member lattice-type structures such as jackets and tripods are also considered good alternatives to monopile foundations for relatively deep water areas with depth ranging from 25-50 m owing to their technical and economic feasibility. Moreover, jacket structures have been popular in the oil and gas industry for a long time. However, several unsolved technical issues still persist in the utilization of multi-member lattice-type supporting structures for OWTs; these problems include pile-soil-interaction (PSI) effects, realization of dynamically stable designs to avoid resonances, and quick and safe installation in remote areas. In this study, the effects of PSI on the dynamic properties of bottom-fixed OWTs, including monopile-, tripod- and jacket-supported OWTs, were investigated intensively. The tower and substructure were modeled using conventional beam elements with added mass, and pile foundations were modeled with beam and nonlinear spring elements. The effects of PSI on the dynamic properties of the structure were evaluated using Monte Carlo simulation considering the load amplitude, scouring depth, and the uncertainties in soil properties.

• 한국지진공학회논문집
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• 제20권3호
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• pp.171-180
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• 2016

Earthquake event keeps increasing every year, and the recent cases of earthquake hazards invoke the necessity of seismic study in Korea, as geotechnical earthquake hazards, such as strong ground motion, liquefaction and landslides, are a significant threat to structures in industrial hub areas including coastal facilities. In this study, systemized framework of integrated assessment of earthquake-induced geotechnical hazard was established using advanced geospatial database. And a visible simulation of the framework was specifically conducted at two coastal facility areas in Incheon. First, the geospatial-grid information in the 3D domain were constructed with geostatistical interpolation method composed of multiple geospatial coverage mapping and 3D integration of geo-layer construction considering spatial outliers and geotechnical uncertainty. Second, the behavior of site-specific seismic responses were assessed by incorporating the depth to bedrock, mean shear wave velocity of the upper 30 m, and characteristic site period based on the geospatial-grid. Third, the normalized correlations between rock-outcrop accelerations and the maximum accelerations of each grid were determined considering the site-specific seismic response characteristics. Fourth, the potential damage due to liquefaction was estimated by combining the geospatial-grid and accelerations correlation grid based on the simplified liquefaction potential index evaluation method.

• 한국환경과학회지
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• 제16권12호
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• pp.1411-1424
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• 2007

Long-term trends and distribution patterns of water quality were investigated in the Asan coastal areas of Yellow Sea, Korea from 1975 to 2005. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns were not clear among stations but the seasonal variations were distinct except COD, SS and nitrate. The trend analysis by principal component analysis(PCA) during twenty years revealed the significant variations in water quality in the study area, Annual water qualities were clearly discriminated into 4 clusters by PCA; year cluster 1988-1991, 1994-1997, and 1992-1993/1998-2005. By this multi-variate analysis we can summarize the annual trends as the followings; salinity, suspended solids and dissolved oxygen tended to increase from late 1980's, increased pH and COD from 1992, and decreased salinity and increased nitrogen and COD from 1990 due to the runoff frow agricultural lands causing eutrophication.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.489-492
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• 2006

In this study we collected and analyzed cases where typhoons damaged coastal structures in Korea in the past 6 years, and hydraulic model tests were conducted in 2D flume. 2 areas where damage was concentrated were selected from ports that had suffered damage. The selected area was Kyungsang-namdo, where there are a total of 26 national ports. Damage to these two areas was organized by wind direction of the typhoons and the direction of the entrance of the port, and destruction patterns were analyzed. 2D hydraulic model tests were conducted of Deabyeun port, one of the damaged areas. Results were as follows: 1. As a result of survey, ports that had entrances that were open to winddirection of typhoon (Anti-clockwise direction) tended to be damaged mare, whereas ports that blocked by island and ports that were not open to wind direction of typhoon were not damaged. 2. As a result of the tests, there was damage that occurred when using the section of designed section, whereas there was no damage when the TTP weight was increased.

• 한국해양학회지
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• 제14권1호
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• pp.1-5
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• 1979

최근에 들어 우리나라는 공업의 급속한 발달과 도시로의 인구집중 및 농약의 남용등으로 하천 및 연안오염이 크게 우려되고 있다. 특히 중금속은 지속성이 커서 일단 자연에 버려지면 바다로 들어가고, 또한 먹이사슬을 통해 생물농축 (Bioaccumulation)되어 결국에는 인간에게 돌아오기 때문에 연안의 중금속 오염현황 조사와 오염방지대책수립은 시급한 업무라 하겠다. 따라서 본 연구실에서는 우리나라의 연안오염 현황파악과 앞으로의 보다 조직적이고 체계적인 조사계획수립을 위해, 1977년 여름철에 주요연안인 묵호 삼척, 울산, 여수 광양, 목포, 군산, 인천해역 해수의 일반수질지수, 영양염류 그리고 중금속(Cd, Cu, Fe, Pb, Zn)의 농도를 조사하였다. 이중에 일반수질지수와 영양염류의 농도조사결과는 전보(이광우외, 1978) 에 발표하였고, 본보에는 중금속의 조사결과를 보고한다.