• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.202-206
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• 2015

해안선은 길게 뻗어 있지만 직선적이지 않고 원호와 같은 곡선을 보인다. 그러나 대부분의 평형 해안선식은 직선적 해안이라고 가정하고 수립되어 그 효용성이 큼에도 불구하고 실 해안에 적용되는 경우 잘 재현하지 못하는 경우가 범용적으로 이용되는 데 큰 걸림돌이 되었다. 특히 해안선의 포괄 원호의 반경이 작을수록 문제가 크다는 점에 착안하여 해안선을 포괄하는 극좌표계에 포물선형 평형 해안선 식을 매핑하는 방법을 적용하였다. 그 결과 control point의 개연성을 극복하였고 대부분의 동해, 서해든 국내 해안에 적용한 결과 만족할 만한 결과를 제공하였다. Matlab GUI로 개발되어 실무자들이 항만이나 어항 등 연안해역 개발에 따른 침식 문제의 근본 해결 방안을 사전에 수립하는 데 큰 도움이 되리라 기대한다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.34-40
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• 1999

Models of beach response due to sea level rise were verified by experiments and potential shoreline retreat around Korea and Japan was predicted. Wave tank experiments demonstrated that not only static retreat by water level rise but also additional retreat by wave action plays an important role in total retreat and additional retreat becomes important on the condition of high waves. The result of long-term analysis of tidal data over past 3 decades shows the tendency toward rise by an average of 1.79 mm/year, which is the result of rise in 29 regions and fall in 12 regions. Based on analyzed rate of long-term sea-level rise, potential shoreline retreats of study area after 50 years were calculated and the result shows serious loss of beach.

• Journal of the Korean Geographical Society
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• v.50 no.2
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• pp.147-164
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• 2015

This study analyzed characteristics and tendencies of seasonal change on shoreline and beach with 8 beaches at East Sea coast by topographical survey for 2 years from March 2012 to February 2013. The shorelines of East Sea coast appeared that amount of seasonal change was bigger than amount of annual change. The seasonal change tendencies between Gangwon-do and Gyeongsangbuk-do coast areas existed some regional differences. To synthesize seasonal changes on 8 beaches of East Sea coast, shoreline advance and beach deposit showed clearly in summer and shoreline retreat and beach erosion showed clearly in autumn. This result is different from tendencies of seasonal change in many mid-latitude coast areas of the world, but generally corresponds with reference studies in west coast and east coast. The major factor of beach erosion showing mostly in summer is storm wave caused by typhoon. The beach erosion by storm wave also occurred in late winter. And it assumes that the beach deposit showing mostly in autumn is result of equilibrium processes of coast area against strong erosion in summer.

• Journal of Ocean Engineering and Technology
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• v.32 no.2
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• pp.123-130
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• 2018

The present study investigated the validity of an equilibrium shoreline empirical formula for real phenomena. Among three types of equilibrium shoreline formulas, Hsu's parabolic type static formula was employed, which is well-known and the most practical for shoreline estimation after coastal or harbor structure construction. The wave data observed at Maengbang beach and the CERC formula on longshore sediment transport were used in the present investigation. A comparison study was only conducted for the case of a shoreline change after the construction of a groyne. Reasonable agreement was seen between the observed wave data and the data obtained under a wave angle spreading function S = 3.5. However, significant changes were observed when S increased. Thus, careful application is required when using Hsu's formula.

• 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 Ocean Engineering and Technology
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• v.14 no.3
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• pp.55-60
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• 2000

This paper is descried the experimental results of beach process including storm surge and beach recovery. By testing different surge levels and durations, effects of these to shoreline change were evaluated. In addition of beach recovery were investigated experimentally. On the other hand, we proposed the method, which can be applicable to complex hydrograph such as storm surge by modifying equation proposed by Kriebel and Dean. Moreover, applicability of this method is verified by comparing computing result with experiments.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.1
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• pp.95-102
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• 1996

The skewness of near-bottom velocity distribution caused by the nonlinear interaction of the second order waves proposed by Wells (1967) has been re-evaluated. The direction of cross-shore sediment transport was related to the sign of the third moment (skewness) of velocity distribution, and a new concept of neutral depth which can explain the recovery of beach equilibrium after a disturbance is suggested. The seasonal change of beach profile due to the change of wave condition (storm-swell profile) is interpreted in terms of nonlinear interaction of the waves rather than the conventional wave steepness. The beach is eroded (storm profile) when the nonlinear interaction of the waves is strong (storm wave), whereas the beach is accreted (swell profile) when the nonlinear interaction is weak (swell wave).

• Journal of Ocean Engineering and Technology
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• v.32 no.2
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• pp.116-122
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• 2018

Dean's equilibrium beach profile formula was used to investigate the correlation between the static shoreline position and the incident wave energy. The effect of the longshore sediment transport was neglected, and the results showed the reasonable agreement compared with the field observations of Yates et al.(2009), which were conducted for almost 5 years on southern California beaches, USA. The shoreline response varies with the scale factor of Dean's equilibrium beach profile. This implies that the shoreline response could be simply estimated using the sampled grain size without laborious long-term field work. Therefore, the present study results are expected to be practically used for the layout design of submerged or exposed detached breakwaters although the further work is required for performance verification. In addition, after laborous mathematical reviews, the linear relation between incident energy and shoreline response, which was obtained from Yates's field study, yielded a clear mathematical equation showing how the beach slope is related to the grain size.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.186-195
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• 2005

Topography of beach line is keeping stability for several years, their soil values have been maintained in balances. Install of coastal structures have caused deformation for beaches and acted as a function to structures. Therefore, quantitative prediction of beaches topography according to structure install is required to prevent the beaches deformation and progress proper coastal preservation work. In this study, we analyzed coastal changes caused by erosion and accretion according to development and drew up a cross-section to share 8 stations using coordinates and depth surveying in groin of Soheuksan island port. Elevation distribution and changes by observation period is calculated -0.30m~+0.20m after comparing results of five months in October 7, 2004 surveying results and fell into insignificance. We thinks periodic observation of coastal erosion and accretion take place for the season and long-term coastal changes in beaches width is analyzed.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.111-125
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• 2001

An estuary is semi-inclosed inlets, located between terrestrial and marine environment. Since many estuaries along south-western coasts of Korean peninsula were affected by human settlements and activities, significant changes in sedimentation environments have been observed. The research area is divided into three distinct morpho-stratigraphic units: fluvial dominated area(Area1), mixed area(Area 2), tide-dominated area(Area3). The landform of this area has been changed by reclamation and river channel change. Temporal variations affected by dam construction, periodic freshet was iterrupted. Sediments began to continuously accmulate on estuary banks by tide. Meanwhile, because of the continuous but reduced discharge of fresh water, the salinity of estuarine sediments was declined. That processes made vegetated area( Phregmites lonivalvis and Suaeda japonica) to be expanded. It indicates that the magnitude and frequency of geomorphic processes has been significantly changed.