• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.11a
• /
• pp.225-226
• /
• 2019

육상에서 발생한 부유쓰레기는 하천을 통해 해상으로 유입되어 선박 프로펠러 파손, 항로 점유 등 선박 운항 안정성에 지대한 영향을 미친다. 본 연구는 육상 기인 부유쓰레기의 해양 확산을 방지하고 나아가 선박 운항 안정성 확보를 위한 차단막과 차단막의 부유쓰레기 차단 성능 확보를 위한 플랫폼 및 계류, 앵커시스템 개발을 연구 목표로 한다. 본 구조물의 우선 설치 대상 해역은 가덕도 남동부 해안으로, 우천시 혹은 태풍 내습시 육상에서 발생하는 많은 해양쓰레기의 확산이 이루어지는 지역이다. 대상 해역의 환경하중 조건에서 플랫폼이 정상기능을 수행하도록 수치해석 기법을 기반으로 플랫폼 및 계류, 앵커시스템을 설계하고 설계 기준 적합성을 평가하였다.

• KASI NEWSLETTER
• /
• s.56
• /
• pp.22-23
• /
• 2006

지난해 한국천문연구원과 (사)한국아마추어천문학회가 주최한 '제1회 아마추어천문인 공로상' 교사 부문을 수상한 박재문 씨는 현재 부산시 가덕도에 위치한 부산덕문중학교 교사로 재직 중이다. 부산이라지만 배를 타고 들어가야 하는 외딴 섬마을에서 박재문씨를 만났다.

• Journal of Life Science
• /
• v.24 no.8
• /
• pp.813-819
• /
• 2014

The spatial distribution of geographical distances at five natural populations of Camellia japonica in Busan, Korea was studied. The four plots (Mollundae, Gadeok-do, Du-do, and Jwiseum) of C. japonica were uniformly distributed in the forest community and only one plot (Amnam-dong) was aggregately distributed in the forest community. Morisita index is related to the patchiness index showed that the plot $20m{\times}50m$ had an overly steep slope when the area was larger than $20m{\times}20m$, which indicated that the degree of aggregation increased significantly with increasing quadrat sizes, while the patchiness indices did not change from the plot $5m{\times}10m$ to $10m{\times}10m$. The spatial structure was quantified by Moran's I, a coefficient of spatial autocorrelation. Ten of the significant values (76.9%) were positive, indicating similarity among individuals in the first 4 distance classes (80 m), i.e., pairs of individuals with dissimilarity characteristics can separate by more than 100 m.

• Korean Journal of Ichthyology
• /
• v.11 no.1
• /
• pp.46-51
• /
• 1999

Age, hatching date and growth in length of juvenile Limanda yokohamae were determined by analysis of microstructure in otoliths. Monthly samples were collected by a beach seine in the shallow water off Gaduk-do from January to December, 1998. The juveniles were collected between February and April. Mean total length was $22.6{\pm}1.77\;mm$ ($\pm$SD) in February, $23.6{\pm}3.86\;mm$ in March, and $38.2{\pm}8.38\;mm$ in April. The core of otoliths ranged from 18 to $21\;{\mu}m$ in diameter and the growth increments were deposited concentrically from the hatching mark. The secondary growth layer began to appear at the 48 to 56-th increment. It indicates that L. yokohamae larvae may be completed the metamorphosis at this time of ca. 52 d after hatching, and moved into the shallow water for demersal stage. The hatching date calculated from the number of daily increments was between late November and early January, showing a peak in December. The total length (L, mm) was related to otolith radius (R, ${\mu}m$); L=0.055 R+5.81 ($r^2=0.88$). The growth in total length was represented by the Gompertz growth curve; $L_t=3.39e^{4.51(1-e^{-0.0067t})}$ ($r^2=0.81$). Daily growth rate was 0.35 mm/d at the age of 70 d and increased up to 0.55 mm/d at the age of 120 d.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.5 no.2
• /
• pp.25-33
• /
• 2002

We were trying to understand indirectly the range of the discharge from the Nakdong with the dispersion of suspended solid(SS) related to the amount of discharge from river in this study. The range of dispersion of SS from the Nakdong was estimated using satellite remote sensing and numerical modeling. The stream field with two dimensional and numerical model using the condition of integrated depth was calculated. According to the results, the streamline flowed from Busan to the Jinhae Bay and Geojae Island. at the flood. The situation at the ebb was totally changed. The streamline flowed out Busan from the Bay. The velocity in offshore was faster than one at coastal water of the Nackdong. Residual current which was averaged during 12hours dominantly appeared the dominant direction from the southwestern part of the Nackdong to the northeastern part of it. The eastward current appeared at the eastern coast of Gaduck Is. Base on the results of the velocity field, the quantifying of the dispersion of SS was estimated by the method of numerical tracer related to the Lagrangian method. The significant range of the dispersion of the SS from the Nackdong was from the eastern coast of Gaduck Is, to the coastal areas of Busan, Korea. The estimated range of the dispersion of the SS using the SeaWiFS and Landsat satellite data was similar to the estimated results using the numerical model.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.12 no.3
• /
• pp.188-196
• /
• 2009

This study conducted numerical simulations to analyze the wave characteristics(distribution) depending on the directional changes of waves in the Nakdong river estuary by using SWAN(Simulating WAves Nearshore) model. The results from the tests are summarized as below. The wave height rates are generally highly distributed with the incident waves from the S, SSE, SSW, SE, SW in sequence. When the waves from the S, SSW, SSE directions are predominant, the bigger waves were observed in front of sandbars. According to the results of the wave steepness against the wave direction, at the east coast of Gadeok island(northwest of Nakdong estuary), where has mild seabed slopes, the wave height rates distribute in the range of 0.4~0.6; the wave height rates over the west coastal region of Dadeapo(southeast of Nakdong estuary) are 0.5~0.6. The wave height rate tends to be rapidly decreased over the east region of Nakdong river estuary rather than its west region.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.2
• /
• pp.95-103
• /
• 2008

Heavy metals in the surface seawaters and sediments were measured in Gaduk channel of jinhae Bay. The high concentrations of heavy metals in the seawaters were found at the stations near the islands. In the seawaters, the mean concentrations of dissolved heavy metals except for Pb were not higher than previous data in this bay. Higher heavy metal contents in the surface sediments were observed at the stations adjacent to the Geojedo or Gadukdo of the Gaduk channel. The contents of Co,Ni,Zn,Cu,As and Cd in the surface sediments showed relatively high correlation coefficients with IL and COD. The order of enrichment factors(EFs) of heavy metals in the sediments on the basis of average shale values was As>Cd>Pb>Zn>Co>Cu>Hg>Ni, and the EFs of As,Cd,Pb and Zn at whole stations were higher than 1. EFs of Ni and Zn on the basis of natural background concentration in Korean coastal sediments were lower than EFs by average shale.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.715-722
• /
• 2002

The monthly collected fish samples by crab pots were analyzed in order to study the species composition and seasonal variation of fish assemblage in the coastal water off Gadeok-do, Korea in 1998, During the study period, 49 species of fishes representing 26 families were collected, The dominant species were Conger myriaster, Sebastes inermis, Hexagrammos otakii, H. agrammus, Stephanolepis cirrhifer and Acanthogobius flavimanus. These 6 dominant species accounted for $67.1\%$ and $69.4\%$ in the number of individuals and biomass, respectively. The secondary importance species were Thamnaconus modestus, Takifugu niphobles, Rudarius ercodes, Dictyosoma burgeri, Sebastes longispinis and Epinephelus septemfasciatus. The highest number of species was collected in November, and the number of individuals and biomass were highest in March. But the lowest numbers of species and individuals were collected in July and the lowest biomass in September, Although the species diversity indices varied little monthly, the lowest value was recorded in August because of small number of species and predominance of 5. cirrhifer and T. modestus.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2009.06a
• /
• pp.452-455
• /
• 2009

The Nakdong Delta can be identified by two different geomorphic units. The first one is the upper delta. This is mostly composed of inter-distributary islands that are largely influenced by fluvial processes and attributed to the development of these islands along the river. The other one is the lower delta which is mostly composed of beach ridges. Barrier islands are largely effected by wave processes promoted by the development almost at a right angle to the river. Influenced by the longshore current which flows to the same direction, barrier islands located in the Nakdong river estuary are developing from east to west direction. As a result, the eastern end of the barrier islands are growing toward the north-west direction effected by tidal current which moves toward the same direction. Barrier islands include the Sinho Island, the Jinwoo Island, the Daema deung, the Janga Island, the Baghap deung, the Sae deung, and the Chulsae deung(Doyeo deung). They have orderly emerged from the sea since 1861. Since 2008, a new Deung, a sand dune growing under sea, has been developing rapidly from Chulsae deung to the Dadaepo beach. It made the sailing of small fisher boats impossible. Tidal currents transported a lot of sand and silt around the barrier islands. The landscape of Nakdong river estuary where many barrier islands are distributed will change rapidly affecting land environment.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.5
• /
• pp.561-566
• /
• 2017

Few studies on the finless porpoise Neophocaena asiaeorientalis have been conducted on the south coast of Korea. This region includes Gadeok Island, which is located off the Korean peninsula in an area of heavy maritime traffic. Sighting surveys of finless porpoises were conducted at seven predetermined spots around Gadeok Island in January, May, July, September, and November 2016. Finless porpoises (127 individuals in 24 schools) were sighted at all but one (spot P5) of the survey locations. Fewer porpoises were spotted in summer (Jul and Sep) than in other seasons (P<0.05). Porpoises were most abundant around the south coast of the island, where they were spotted in every season, and in significantly higher numbers than at other locations (P<0.05). Single individuals accounted for 20.8% of sightings, while 25.0% of sighted schools consisted of only two porpoises. The mean school size was 5.29 individuals (SD=6.72).