• Title/Summary/Keyword: 연안방향

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The Variations of Oceanic Conditions and the Distributions of Eggs and Larvae of Anchovy in the Southern Sea of Korea in Summer (하계 한국 남해의 해황 변동과 멸치 초기 생활기 분포특성)

  • Choo Hyo Sang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.1
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    • pp.77-85
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    • 2002
  • In the southern sea of Korea and the areas of Tsushima warm currents the relationship between the distributions of eggs and larvae of anchovy (Engraulis japonica) and oceanic conditions was examined on July and August 1997, The south Korean coastal waters, the water temperature of below $20\~23^{\circ}$ and the salinity of above 33.0 (PSU), the mixed waters between the south Korean coastal waters and the Tsushima warm currents, $21\~25^{\circ}$ and $32.0\~32.5$ and the Tsushima warm currents, above $26^{\circ}$ and below 31.5 were distributed at the surface layer. The Tsushima warm currents were distributed at the northeast of Jeju Is. and off the southern sea of Korea. As an appearance of warm streamer, the mixed waters were intruded into the coastal areas of Komun Is.$\~$Sori Is. and Sori Is.$\~$Yokji Is.. Approximate paths of surface water by the drift card experiments were similar with the intrusions of the warm water identified from the water temperature and salinity distributions. The distributions of chlorophyll concentration were consistent with the distributions of water temperature and salinity, Anchovy eggs and larvae were mostly distributed at Komun Is., Yokji Is, and the southwest of Koie Is. where chlorophyll concentrations were high and cyclonic circulations by the warm water intrusions (warm streamers) were formed.

Risk Assessment of the Accident Place Types Considering the Coastal Activity Time (연안활동시간을 고려한 장소유형별 위험도 평가)

  • Seo, Heui Jung;Park, Seon Jung;Park, Seol Hwa;Park, Seung Min
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.34 no.5
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    • pp.144-155
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    • 2022
  • The Korea Coast Guard evaluates the risk of major coastal activity places to prevent coastal accidents, and patrols and manages them based on that, but it is not responding properly to the continuously increasing number of coastal accidents. The reason for this is that, despite the gradual expansion of coastal activity places, there is a lack of manpower to manage and supervise them, resulting in blind spots in coastal accident safety management. Therefore, in order to solve this problem, it is necessary to prepare more efficient and effective measures that check and supplement the current coastal safety management system. Coastal accidents show different characteristics of accident causes and places due to differences in the activity characteristics of users according to time. As a result of analyzing coastal accident data (2017~2021), the frequency of daytime accidents is high in the case of sea rock, beach, and offshore, where family leisure activities are frequent. In the case of wharf, tidal flat and bridge, where accidents due to drinking, disorientation, and suicide mainly occur, the frequency of accidents at night is high. In addition, there were more accidents on weekends when the number of users increased compared to weekdays. This trend indicates that the user's temporal activity characteristics must be reflected in the risk assessment of coastal activity places. Therefore, in this study, based on the case of coastal accidents, the characteristics of accidents at coastal activity places according to time were identified, and the criteria were presented for risk evaluation by grading them. It is expected that it will be possible to lay the foundation for reducing coastal accidents by efficiently managing and supervising coastal activity places over time using the presented evaluation criteria.

Analysis on the Area of Deltaic Barrier Island and Suspended Sediments Concentration in Nakdong River Using Satellite Images (위성영상을 활용한 낙동강 삼각주 연안사주의 면적 및 부유퇴적물 농도 변화 분석)

  • Eom, Jinah;Lee, Changwook
    • Korean Journal of Remote Sensing
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    • v.33 no.2
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    • pp.201-211
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    • 2017
  • The estuary in Nakdong River has changes by the construction of harbors, land reclamation and artificial waterway changes. These resultslead to changes of extinction and creation of deltaic barrier island. The deltaic barrier island changes in the Nakdong River estuary affect the function of the barrier islands and cause environmental changes. Therefore, it is important to monitor the changes in the area of the Nakdong estuary. In this study, long-term changes of the area and suspended sediment of deltaic barrier island in the Nakdong River estuary were analyzed using Landsat TM/ETM+ images. As a result, end point rate (EPR) values of shoreline in Jinwoodo and Sinjado are about 5m/yr and about 50 m/yr, respectively. The EPR values of north-south and east-west direction in Doyodeung are 20 m/yr and -20 ~ 10 m/yr. The suspended sediment concentration (SSC) has a maximum value of $25g/m^3$ in the vicinity of Jinwoodo and Sinjado, while it has a maximum concentration of $40g/m^3$ in the vicinity of Shinjido and Doyodeung. In other words, the area and the SSC change are small in Jinwoodo, and the area change and the SSC variation are large in Sinjado and Doyodeung. As a result of analysis of correlation between area change and SSC variation using all data, the Pearson coefficient value (r) is 0.36 and it is 0.32 in winter data. In other words, it is considered that the SSC variation affectsthe deltatic barrier island area change. However, verification using advanced altimetry data is necessary in the future. These studies can be used for coastal monitoring and environmental monitoring.

A Relationship between Oceanic Conditions and Meteorological Factors in the Western Sea of Korea in Winter (동계 서해의 해황과 기상인자와의 관계)

  • Go Woo-Jin;Kim Sang-Woo;Kim Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.23-32
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    • 2006
  • This study was conducted to find out the effects of meterological factors on oceanic conditions when cold and dry continental air mass passes through the western sea of Korea The change of ocean conditions during the winter season were more obvious in coastal area than open sea And sea surface temperature (SST) during February is lower by $3^{\circ}C$ than December but in coastal area SST dropped by $3^{\circ}C$. As for the salinity, there was not much difference between areas except southern area of Mokpo. In the coastal regions, air temperature(AT) and SST showed a positive correlation; as the air temperature goes up with the increase of SST and when the former goes down the latter decrease. SST of open sea seems to be changed by latent (Qe) and sensible heat (Qs), when the open sea lose its heat by Qe and Qs then SST goes down And when they get the heat then the SST goes up. 1here was a positive correlation between the AT of the coastal region and sea surface salinity (SSS), when the AT goes up then SSS increase and when the former goes down the latter decrease. Precipitation during the summer seasons (June$\sim$September) appeared to the more closely related with salinity of February of the following year than those of October and December.

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Suggestions for Building Coast-Inland Linkage Transport System to Promote Island Tourism (도서관광 활성화를 위한 연안-내륙 연계교통체계 구축 방향)

  • Choi, Chang-Ho
    • Journal of Korea Port Economic Association
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    • v.28 no.2
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    • pp.43-59
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    • 2012
  • Recently, there has been a noticeable increase in the number of tourists in islands that are well-known for their natural landscapes. It is expected that this number will go up steadily, due to the increase in per capita income and leisure time. Regarding tourism transportation, utilizing linkage transport between coastal passenger terminal and inland transport system is crucial. However, the existing system does not measure up to the expectations. This is attributable to the fact that the distances between coastal passenger terminals and inland transportation terminals are too far. Also, the current public transportation system lacks support and needs to take the role of connecting the two terminals. This study shows how coast-inland linkage transport system should be reformed in order to promote island tourism. It focuses on building linkage transport system and minimizing walking distance. Also, adjusting passenger ship schedule to the characteristics of island tourism is needed. For the sake of passengers, coastal passenger ship fare should be reduced, and integrated transport information should be provided.

Coastal Current Along the Eastern Boundary of the Yellow Sea in Summer: Numerical Simulations (여름철 황해 동부 연안을 따라 흐르는 연안 경계류: 수치 모델 실험)

  • Kwon, Kyung-Man;Choi, Byoung-Ju;Lee, Sang-Ho;Cho, Yang-Ki;Jang, Chan-Joo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.4
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    • pp.155-168
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    • 2011
  • Coastal boundary current flows along the eastern boundary of the Yellow Sea and its speed was about 0.l m/s during the summer 2007. In order to find major factors that affect the coastal boundary current in the eastern Yellow Sea, three-dimensional numerical model experiments were performed. The model simulation results were validated against hydrographic and current meter data in the eastern Yellow Sea. The eastern boundary current flows along the bottom front over the upper part of slopping bottom. Strength and position of the current were affected by tides, winds, local river discharge, and solar radiation. Tidal stirring and surface wind mixing were major factors that control the summertime boundary currents along the bottom front. Tidal stirring was essential to generate the bottom temperature front and boundary current. Wind mixing made the boundary current wider and augmented its north-ward transport. Buoyancy forcing from the freshwater input and solar radiation also affected the boundary current but their contributions were minor. Strong (weak) tidal mixing during spring (neap) tides made the northward transport larger (smaller) in the numerical simulations. But offshore position of the eastern boundary current's major axis was not apparently changed by the spring-neap cycle in the mid-eastern Yellow Sea due to strong summer stratification. The mean position of coastal boundary current varied due to variations in the level of wind mixing.

The Morphological Changes of Deltaic Barrier Islands in the Nakdong River Estuary after the Construction of River Barrage (하구둑 건설 이후 낙동강 하구역 삼각주 연안사주의 지형변화)

  • Kim, Sung-Hwan
    • Journal of the Korean Geographical Society
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    • v.40 no.4 s.109
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    • pp.416-427
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    • 2005
  • This paper aims to investigate morphological changes of deltaic barrier islands in the Nakdong Estuary and especially their spatial variations after barrage construction. We analyzed shorelines, geometrical centroids, and areas to reveal the changes of barrier islands. Here, we suggest three interesting points from this study. First, each individual barrier island in the Nakdong estuary goes through a different stage of the geomorphic cycle. The frontal barrier islands such as Sinja-do and Doyo-deung grow because they are located in front of the gates of the barrage. Sediments in water out of the gates are moved to offshore and then reworked by coastal processes such as waves and tides. Second, on the contrary, Baekhap-deung located behind Doyo-deung now diminishes indicating that sediments mainly move to the frontal growing island. Third, there is no morphological change in several barrier islands far away from the main flow of the Nakdong river such as Jinwoo-do, Daema-deung, and Jangja-do. In conclusion, barrier islands in the Nakdong estuary show distinct spatial variations. As a barrier island is closer to the main channel or is in the frontal location, there happens a very dynamic change in the morphology of the island.

A Study on the Improvement of Integrated Coastal Zone Management System for Efficient Use of National Land (국토공간의 효율적 활용을 위한 연안통합관리체계 개선방안에 관한 연구)

  • Lee, Kil Jae;Lee, Joo Hyung
    • Spatial Information Research
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    • v.22 no.5
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    • pp.99-107
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    • 2014
  • The purpose of this study is to formulate various improved working schemes in determining the definition of non-permissible activities to strengthen the practical implementation and operation of the integrated coastal management plan for regional self-governing authorities In this study, non-permissible activities indicate any activities which should be restricted according to the coastal functions of five different sectors in the regional plan for coastal management. Coastal management plan, are classified into four areas along the coast to use direction. It prohibited and support matters of another coastal exploitation each area. If you want to set the coastal area, has already been specified in the regional and global based on that region Land use planning and urban planning. When additional area settings in some cases may lead to conflicting results. Analyzes the factors to consider about the range and use areas set of in coastal management, It is necessary to strive for deriving a scheme to solve the existing contradiction between the state of the local - area specified problem. With the help of marine spatial planning and pointed out institutional and urban planning system to be utilized in land in the ocean for a more accurate and efficient coastal management, and registered the coastal areas, there is a need to manage. Land -use planning, consideration of another consultation body organization that is able to develop a plan that was comprehensive and marine spatial planning, The contradiction consider to specify the various areas and regions where other specific identification method is determined, Setting the range of coastal waters (within 3 nautical mile), I was exploring the coast registration scheme and registration target, etc.

On-offshore Distribution of Longshore Current in the Surf Zone (쇄파후(碎波後) 발생(發生)하는 연안류(沿岸流)의 유속분포(流速分布)에 관한 연구(研究))

  • Kim, Kyoung Ho;Koo, Bong Kuen
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.6 no.4
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    • pp.11-19
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    • 1986
  • This study aims at the elucidation of the distribution of longshore currents after wave breaking. Longshore currents have relations to the beach process and dispersion of contaminants in the nearshore region, thus the understanding of its. mechanism is very important. In the present study, using the electromagnetic current meter, the water particle velocity is measured in the 3-dimensional wave field and Eulerian mean velocity is obtained. At the same time, from the dispersion of tracer, the Lagrangian mean velocity is also obtained. It is observed that the longshore currents were confined within the surf zone and the maximum value of them exists in the surf zone. The longshore currents were considered to be constant toward the depth and we obtained the similar distribution of longshore currents between the measured value and the theoretical ones by Longuet-Higgins model.

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