• Title/Summary/Keyword: Coastal Zone

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Construction of a artificial levee line in river zones using LiDAR Data (라이다 자료를 이용한 하천지역 인공 제방선 추출)

  • Choung, Yun-Jae;Park, Hyeon-Cheol;Jo, Myung-Hee
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.185-185
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    • 2011
  • Mapping of artificial levee lines, one of major tasks in river zone mapping, is critical to prevention of river flood, protection of environments and eco systems in river zones. Thus, mapping of artificial levee lines is essential for management and development of river zones. Coastal mapping including river zone mapping has been historically carried out using surveying technologies. Photogrammetry, one of the surveying technologies, is recently used technology for national river zone mapping in Korea. Airborne laser scanning has been used in most advanced countries for coastal mapping due to its ability to penetrate shallow water and its high vertical accuracy. Due to these advantages, use of LiDAR data in coastal mapping is efficient for monitoring and predicting significant topographic change in river zones. This paper introduces a method for construction of a 3D artificial levee line using a set of LiDAR points that uses normal vectors. Multiple steps are involved in this method. First, a 2.5-dimensional Delaunay triangle mesh is generated based on three nearest-neighbor points in the LiDAR data. Second, a median filtering is applied to minimize noise. Third, edge selection algorithms are applied to extract break edges from a Delaunay triangle mesh using two normal vectors. In this research, two methods for edge selection algorithms using hypothesis testing are used to extract break edges. Fourth, intersection edges which are extracted using both methods at the same range are selected as the intersection edge group. Fifth, among intersection edge group, some linear feature edges which are not suitable to compose a levee line are removed as much as possible considering vertical distance, slope and connectivity of an edge. Sixth, with all line segments which are suitable to constitute a levee line, one river levee line segment is connected to another river levee line segment with the end points of both river levee line segments located nearest horizontally and vertically to each other. After linkage of all the river levee line segments, the initial river levee line is generated. Since the initial river levee line consists of the LiDAR points, the pattern of the initial river levee line is being zigzag along the river levee. Thus, for the last step, a algorithm for smoothing the initial river levee line is applied to fit the initial river levee line into the reference line, and the final 3D river levee line is constructed. After the algorithm is completed, the proposed algorithm is applied to construct the 3D river levee line in Zng-San levee nearby Ham-Ahn Bo in Nak-Dong river. Statistical results show that the constructed river levee line generated using a proposed method has high accuracy in comparison to the ground truth. This paper shows that use of LiDAR data for construction of the 3D river levee line for river zone mapping is useful and efficient; and, as a result, it can be replaced with ground surveying method for construction of the 3D river levee line.

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A hydrodynamic model of nearshore waves and wave-induced currents

  • Sief, Ahmed Khaled;Kuroiwa, Masamitsu;Abualtayef, Mazen;Mase, Hajime;Matsubara, Yuhei
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.3 no.3
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    • pp.216-224
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    • 2011
  • In This study develops a quasi-three dimensional numerical model of wave driven coastal currents with accounting the effects of the wave-current interaction and the surface rollers. In the wave model, the current effects on wave breaking and energy dissipation are taken into account as well as the wave diffraction effect. The surface roller associated with wave breaking was modeled based on a modification of the equations by Dally and Brown (1995) and Larson and Kraus (2002). Furthermore, the quasi-three dimensional model, which based on Navier-Stokes equations, was modified in association with the surface roller effect, and solved using frictional step method. The model was validated by data sets obtained during experiments on the Large Scale Sediment Transport Facility (LSTF) basin and the Hazaki Oceanographical Research Station (HORS). Then, a model test against detached breakwater was carried out to investigate the performance of the model around coastal structures. Finally, the model was applied to Akasaki port to verify the hydrodynamics around coastal structures. Good agreements between computations and measurements were obtained with regard to the cross-shore variation in waves and currents in nearshore and surf zone.

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.

Diffraction Effects of Parabolic Mild-Slope Equations in the Shadow Zone behind a Detached Breakwater (이안제 배후 차폐역에서 포물선형 완경사방정식의 회절효과)

  • 김인철
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.4
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    • pp.297-304
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    • 1996
  • The purpose of this study is to observe the applicability of parabolic mild-slope equations allowing relatively large angles of wave propagation based on the use of a Pade approximant or minimax approximation and also the applicability of the models with nonlinearity of diffracted waves in the shadow zone behind coastal structures. To accomplish these objectives, numerical solutions are obtained from the above parabolic models and are compared with the results from Watanabe and Maruyama's(1984) hydraulic model test on the wave field with an impermeable detached breakwater. From this study, it is found that computed wave heights increase for the nonlinear results in comparison to the linear results due to the increased diffraction effect across the geometric shadow boundary. The model with a larger aperture with respect to the principal direction was found to spread laterally to a much greater degree where spreading angle (diffraction effect) is relatively large. which causes a distortion in the overall results due to the error accumulated by the approximation of wave length.

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Modeling of Water Quality with Sediment-Water Interaction at Sea Bottom in Semi-enclosed Coastal Waters - Application to Osaka Bay (폐쇄성 내만에 있어서 수질$\cdot$저질 상호작용 모델링)

  • Han, Dong-Jin;Yoon, Jong-Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.17 no.3
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    • pp.129-137
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    • 2005
  • In this study, we developed a model to simulate the interaction between sediment and the overlying water. The model deals with water-sediment interaction in terms of the sedimentation of organic detritus from the pelagic zone into the benthic zone and the release of nutrients occurring in the reverse direction. The model was tested and verified by comparing the predicted release rates of phosphorus from the sediment in Osaka Bay with actual observed values. The results accurately reproduced the seasonal change in release rates. The results well represented seasonal change of the release rates. A long-term prediction of water and sediment quality was performed for the period from 1950 to 1999. Nutrient loads from land and the boundary conditions of 3-D baroclinic flows were season-adjusted. The model accurately reproduced the changing trends in phosphorus, nitrogen, and COD concentrations in Osaka Bay over a long period of time.

Real-time monitoring of ship's dynamic behavior characteristics by AIS (AIS에 의한 선박거동의 실시간 모니터링)

  • Lee, Dae-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.3
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    • pp.218-228
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    • 2008
  • This paper describes on the real-time tracking of ship's dynamic behavior by AIS information in the coastal waters. The AIS data was received at a land station by using the antenna of AIS receiver mounted on the rooftop of the laboratory, Pukyong National University (PKNU), Busan, Korea, and stored as a NMEA format of serial output sentence of VDM(VHF Data-Link Message) and displayed on the ENC(Electronic Navigational Chart) of a PC-based ECDIS. In this study, the AIS receiver was mainly used to obtain the dynamic information that is necessary to evaluate and track the movement situation of training ship "KAYA" of PKNU in the coastal waters. The change of position with time for the ship turning under the rudder angle of port $30^{\circ}$ was correctly tracked with the turning circle of 940 m in diameter on the ENC of a PC-based ECDIS. Then, the dynamic information of the AIS system was updated every 6.29 seconds under the turning situation for the speed of 10.9 knots and every 21.65 seconds under the situation running at the speed of 11.05 knots on the straight line route of $155^{\circ}$, respectively. In case of AIS target tracking in the inshore zone behind large topographical obstructions, such as mountain and apartment buildings, the update rate of dynamic information was irregularly changed by the existence of land obstacles. However, the position tracking by AIS information under the situation existing no sea obstructions was achieved in real or near real-time and the instant presentation of course alternations for the ship was correctly monitored by using a PC-based ECDIS. From these results, we concluded that the PC-based ECDIS technology and methodology combined with the AIS information can be easily extended and applied to the surveillance and management for the fishing operation of fishing vessels in the coastal zone and in the EEZ fishing grounds.

The classification of extreme climate events in the Republic of Korea (우리나라 극한기후사상의 기후지역구분)

  • Park, Chang Yong
    • Journal of the Korean association of regional geographers
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    • v.21 no.2
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    • pp.394-410
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    • 2015
  • This study aims to classify climate zones for extreme climate indices over the Republic of Korea. First, frequencies and magitudes of extreme high temperature, spatial distributions for extreme low temperature, and extreme precipitation are analysed. Frequencies of summer days in inland region show more than coastal region. In frequencies of frost days, the characteristics of altitude and longitude are appeared. Heavy precipitation days show many frequencies in the southern coastal region and Jeju island, but little in Gyeongsangbuk-do region. The classification of climate zone for extreme climate indices by principal component analysis and cluster analysis is conducted for the first half, second half of study period, and climatology period for 1981-2010. Summer days are classified according to latitude. In case of frost days, the eastern and the southern coastal region and Jeju island are classified as same region. Heavy precipitation days are classified according to longitude in south region of Gyeonggi-do and Gangwon-do. This study will help to prepare adaptation and mitigation system for climate change in wide range of fields.

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Development of the Inter-tidal Exposure Duration Formulae Using Tidal Harmonic Constants (조화상수를 이용한 조간대 노출시간 추정공식 개발)

  • Jeong, Shin Taek;Cho, Hongyeon;Ko, Dong Hui
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.5
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    • pp.319-325
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    • 2012
  • A new formulae for the estimation of the exposure duration in the inter-tidal zone are developed. The exposure duration is one of the most important factors influencing the habitat distribution of the benthic organisms. The formulae can estimate the exposure duration only using the four major tidal harmonic constants available in almost coastal areas. It is easier than the existing method using the frequency analysis of the hourly tidal elevation data. The estimation results by using the formulae suggested in this study are compared with the value by using the observed tidal elevation data analysis in the west coast, Korea. The mean RMS (root-mean squared) errors ranged form 0.8 to 1.4%. It can be used to simply estimate the accurate exposure duration in the region not having the longterm hourly tidal elevation data.

A study on the Residential Satisfaction of Environmental Condition for Housing Complexes located in Coastal Areas (연안역에 입지하는 주거단지 생활자의 거주환경 만족도에 관한 연구)

  • Lee, Myung-Kwon
    • Journal of Navigation and Port Research
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    • v.32 no.6
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    • pp.505-513
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    • 2008
  • Regarding the developmental plans for the coastal areas and marine architectures, this study deal with the overall planning of apartment complexes in waterfront areas, focusing upon the analysis of their comfort and convenience factors from the perspective of the potential residence. It also analysis the intra-complex comfort and satisfaction conditions in terms of their floor-by-floor, directional. and location factors. The results of the study are as follows: 1) The order of respondents' preference on directional factor has been found to be: South > Southeast > Southwest > East > others. 2) 67% of the people surveyed on scenery responded that outward view is considered more significant than the directional factor. 3) A comprehensive analysis of floor zone-specific view preference shared that there were only minor differences among quay wall, arc, and river-seashore types. The impact of the characteristics of the marine environments turned out to be a greater point of consideration; showing that the other of floor-preference is: high-level > ultra-high level > middle level > low level.

Research on the Implementation of the Bilateral Fisheries Order in the East China Sea after Establishing the China-Japan Fisheries Agreement (중·일 어업협정에 따른 양국 어업질서의 이행 실태 진단)

  • KIM, Dae-Young
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.4
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    • pp.1053-1062
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    • 2015
  • This research assesses the implementation of the bilateral fisheries order of the China-Japan fisheries agreement. After establishment of UNCLOS, the China-Japanese fisheries agreement has played as a basis for the fisheries order in the East China Sea. The China-Japanese fisheries agreement intends that the fisheries industries in China and Japan can utilize the renewable natural resources in the East China Sea. As the EEZ of China overlaps with that of Japanese in the East China Sea, the two countries established the China-Japan Provisional Measure Zone and Middle Zone in the Sea. Even though the three coastal States (e.g. Korea, China, and Japan) in the East China Sea are involved in managing these zones, there has been little effort to coordinate each county's management. Additionally, the Taiwan-Japan fisheries agreement, which is for the area of N $27^{\circ}$, has made costal States to establish and implement united measures to conduct effective fisheries management. Regarding access to the joint fishing zone in EEZ, Chinese fisheries regulations have been enforced in the zone because the fishing capacity of China exceeds all of other countries, reducing the number of fishing licenses and catch quotas. It turned out that a nation that has authority over fisheries resources tends to establish specific conditions of fishing operations to maximize its national interest. In the China-Japan Provisional Measure Zone, Chinese and Japanese authorities have introduced united measures to manage fisheries resources. However, in the Middle Zone between China and Japan, there is no regulation on fishing; both countries' fishing vessels can have free access to the zone. Thus, it is recommended that one should introduce an international fisheries management regime for the Middle Zone. In this regard, Korea should play a leading role in establishing the international management regime because Korea has middle position in terms of geographical standpoint, the degree of dependence on commercial fishing, and its fishing capacity.