• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.151-159
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• 2020

This paper puts forward protection strategies for the environmental problems of Busan coastline, providing theoretical basis and guiding standards for the tourism development and environmental transformation of the coastline. The order of research is to deduce the factors that affect environmental problems from the theoretical coastline development characteristics. The investigation method of spatial structure combined with time axis is adopted, and historical images and image processing techniques are used to find the characteristics of morphological changes of Busan coastline. The three types of natural coastline, artificial coastline and ecological restoration coastline are analyzed through the five factors that affect the fluctuation, extensibility, greening rate, concealment and vision of space. According to the above discussion, international competition examples are introduced to find solutions. Finally, environmental protection schemes are put forward from five aspects of tourism, accidents, development, culture and transformation. In the future research, it will focus on the transformation of coastline space to provide a more humanized activity space for coastline residents.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.1
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• pp.19-26
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• 1989

The quantification of phenomena presented by the shoreline changes and the prediction of future changes of shoreline are investigated by using a numerical model in this study. Shoreline has been sucessively affected by the activities of reclamation to maximize the land use and it also has been changed with cycles of accumulation and erosion of deposits. Many researches were performed on the jetties constructed to protect facilities adjacent to the shore. However, few studies on a seawall of protecting the beach, being very important in terms of land use, were carried out. Therefore, this study is to analyze effects of a straight seawall to shoreline changes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.8 no.2
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• pp.9-16
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• 1990

This is a geodetic study on the the shoreline changes occurred by the facilities constructed in the beach. There are emperical, hydrological and numerical methods in predicting of the shorline changes. Numerical method is the most suitable method in the field of geodesy. There are many predicting models. This study adopted one-line model because it has a few hydrological factor and simplify the natural phenomena. This study established the ideal seawall boundary condition, applied the explicit model and the implicit model in the Dongsan harbour in East Sea, and could predict the optimum seawall position for protection of shore. The results are following ; Seawall protect shore of which input angle of wave is below 20$^\circ$, a ratio of wave height bleak/line does not effect in shoreline changes. The implicit model is accuracy but can not predict longtime change. But the explicit model is the opposite of the implicit model.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.31-34
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• 2002

Bragg 반사는 입사된 주기파의 진폭이 해저지형의 진폭의 2배가 될 때 파랑의 반사율이 공명현상(resonance)에 의해 매우 커지는 물리적 현상을 말한다. Bragg 반사를 응용할 경우, 외해로부터 입사되는 파랑 에너지의 상당량을 반사시킬 수 있으므로 항만이나 방파제 등의 해안구조물을 경제적으로 설계하고 보호할 수 있다. 또한, 해안선 보호 및 불필요한 침식이나 퇴적 등을 고려한 연안개발계획의 효율적 수립이 가능하다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.245-248
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• 2003

Bragg반사는 입사된 주기파의 파장이 해저지형의 파장의 두 배가 될 때 공명현상(resonance)에 의해 반사율이 매우 커지는 물리 현상을 말한다. 즉, 외해에서 주기성을 띄는 파랑이 입사해 올 때, 특정형태의 해저지형을 이용하면 상당량의 에너지를 외해로 반사시킬 수 있다. 이와 같은 Bragg 반사개념을 수중방파제(submerged breakwater)에 응용하면 항만이나 방파제 등의 해안구조물을 경제적으로 설계 및 보호 할 수 있고, 해안선 보호 및 불필요한 퇴적 등을 고려한 연안개발계획의 효율적 수립이 가능하다. (중략)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.421-428
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• 2008

For last decades, the rapid coastal erosion process spreading along Korean peninsular has become a nuisance especially for tourism and local economy. Global warming and sea-level rise demand persistently new coastal protection strategies against the conventional methods using armored structures. In a view of this, Kweon et al. (2007) has proposed a new type of horizontal steel plates for an ideal candidate as eco-friendly detached breakwater systems for global warming era. The breakwater is composed of piles and horizontal porous plates that was devised for the optimized blockage effects and wave energy dissipations. This system provides outstanding performances as wave barrier and added advantages such as a rapid installation, an easy relocation, a perfect water circulation for the stagnation of pollutions in sheltered regions. The present experimental study focuses on the performance evaluations of the proposed system in wind wave conditions as a wave dissipator and reflector. The reflection, transmission, and energy dissipation of the random waves has been discussed in detail based on a newly proposed relation between wave steepness and a plate width normalized by wave length that are major factors affecting the wave transmission.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.914-918
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• 2008

연안지역의 갑작스런 개발은 예상치 못한 여러 가지 문제들을 발생시키고 있다. 이와 같은 문제들 중에서 가장 심각한 문제는 해안침식이다. 해안침식은 어떤 원인에 의해 토사의 평형이 손상되어 퇴적되는 양보다 더 많은 양이 유실되면서 해안선이 점점 후퇴하는 현상이다. 해안에 쌓여 있는 모래는 태풍과 폭풍해일로부터 육지를 보호하는 완충지대의 역할을 하고, 또한 관광자원으로도 그 활용가치가 증가하고 있기 때문에 침식현상을 분석하고 침식의 발생 및 진행을 억제하기 위한 연구가 반드시 필요하다고 하겠다. 본 연구에서는 해안침식을 제어하기 위한 기초적인 연구의 일환으로 연안류에 따른 연안표사의 분포특성에 대하여 살펴보았다. 연안류는 표사 이동이 가장 활발한 쇄파대로부터 해안선 사이에서 발생하는 흐름으로 파랑에 의해 발생한다. 일정경사를 갖는 해빈에 대해 연안류를 계산하고 계산된 연안류를 Komar(1977)가 Bagnold(1963) 모형을 이용하여 파의 응력과 흐름속도의 곱의 함수로 연안표사의 분포를 나타나낸 식에 대입하여 연안류에 따른 연안표사의 분포를 계산하였다.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.209-218
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• 2011

The present study proposes a new estimation relationship for the transmission rate of the steel breakwater which is expected to make up for the weakness points in existing hard solution for shore protection. The steel breakwater consists of the wave dissipator of the dual horizontal plates, the supporting columns and their foundations, and thus its respective designs should also be conducted one by one. Furthermore, the breakwater has to ensure both functions of shore protection and structure stabilization. The study produced experimental data for the stability and safety investigation of the steel breakwater. The forces acting on the steel breakwater were classified into two categories, one is vertical up and down loads for the pile resistance and the other was maximum difference of the vertical load acting on horizontally different position for the torsion. The study applied the stability force produced by the summation of maximum pressure at each point and the safety force acting on each point simultaneously. The regular wave corresponding to the significant wave was utilized for measuring wave pressure and force. The study showed the method for the proper position of submerged upper plate by considering occurrence frequency of tide level. The design process finally determined by trial and error is proposed in the present study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.691-699
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• 2021

The global surface temperature has risen critically over the past century and according to the IPCC Fifth Assessment Report 2014, existing risks in natural and human systems will worsen. Coastal erosion is mostly caused by climate change and among all the coastal areas at risk, Benin, which is part of the Gulf of Guinea, has been ranked very highly as a vulnerable region. Therefore, in this review, we focus on the evolution of coastline change in Cotonou of Benin, summarizing its resultant impacts and applied measures around the coast area by reviewing previous studies. Signs of coastal erosion in Cotonou appeared in 1963. After 39 years, the east shoreline of Cotonou has retreated by 885 m, resulting in the disappearance of more than 800 houses. To solve this problem, Benin authorities built seven groynes in 2013, and have increased the number of the structure as a way to interrupt water flow and limit the movement of sediment. Over the region, shorelines appeared preserved accordingly. In contrast, areas located further east, where groynes were not installed, have suf ered from intensive erosion at a rate of 49 m/yr. In the future, as a next step, the effectiveness of groynes should be studied with local and broader perspectives.

• Journal of Korea Water Resources Association
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• v.49 no.5
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• pp.431-438
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• 2016

Large energy consumption is one of the main weaknesses of RO desalination. A new method is proposed to reduce the energy consumption of RO desalination which depends on the salinity of the feedwater. Low salinity feedwater can be obtained using groundwater wells which extracts both fresh groundwater and subsurface sea water. Subsurface feedwater is advantageous in overcoming other problems associated with surface seawater intakes. Salinities of groundwater depend on a number of factors. In this work a new simulation-optimization model is proposed to identify well locations and pumping rates with would provide the required design flow rate with the minimum salinity. When groundwater is developed in a coastal area, the saltwater wedge advances inland and may contaminate existing groundwater wells, which must be prevented. The model can protect existing wells while developing minimum salinity feedwater. Examples are provided to demonstrate the usage of the model.