• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.2
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• pp.41-51
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• 2013

The tidal creek dependent mass transport characteristic in Gyeong-Gi Bay (west coast of Korea) was studied using field measured data and numerical model. Gyeong-Gi Bay consists of 3 main tidal channels and contains a well-developed vast tidal flat. This region is famous for its large tidal difference and strong current. We aim to study the effect of tidal creek in the tidal flat on the mass exchange between the estuary and the ocean. For numerical application, the application of unstructured grid feature is essential, since the tidal creek has complicated shape and form. For this purpose, the FVCOM is applied to the study area and simulation is performed for 2 different cases. In case A, geographic characteristics of the tidal creek is ignored in the numerical grid and in case B, the tidal creek are constructed using unstructured grid. And these 2 cases are compared with the field measured cross-channel mass transport data. The cross-channel mass transport at the Yeomha waterway mouth and Incheon harbor was measured in June, 9~10 (Spring tide) and 17~18 (Neap tide), 2009. CTD casting and ADCP cross-channel transect was conducted 13 times in one tidal cycle. The observation data analysis results showed that mass transport has characteristic of the ebb dominance Line 1 (Yeomha waterway mouth), on the other hand, a flood dominant characteristic is shown in Line 2 (Incheon harbor front). By comparing the numerical model (case A & B) with observation data, we found that the case B results show much better agreement with measurement data than case A. It is showed that the geographic feature of tidal creek should be considered in grid design of numerical model in order to understand the mass transport characteristics over large tidal flat area.

• Journal of Korea Port Economic Association
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• v.23 no.1
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• pp.163-193
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• 2007

Jeon-buk is well equipped for the growth of the logistics industry as it is the center of inland and marine traffic. However, it was not activated because of the infrastructure insufficiency. This paper surveyed the logistics industry facilities, interviewed people who are engaged in its business, researched into their business difficulties and the problem of the logistics industry of Jeon-buk. As a result of research, this paper makes an alternative plan for the development of the logistics industry of Jeon-buk area.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.4
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• pp.361-374
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• 2007

This study presents long-term shoreline changes of barrier islands in Nakdong Estuary using aerial photographs. Digital photogrammetry is used for constructing mosaic aerial photographs, which yield six sets of shoreline data ranging from 1975 to 2001. Three kinds of rate of shoreline changes such as EPR (End Point Rate), JKR(Jackknife Rate) and LRR (Linear Regression Rate) are computed by a GIS-based Digital Shoreline Analysis Systems. There have been remarkable changes both in Sinja Island and Doyodeung. Western part of Sinja Island advanced seaward, whereas eastern part retreated landward, giving appearance that the island rotated counterclockwise. Rate of shoreline changes at both ends reach 20 m/yr. Doyodeung occurred newly in front of Baekhapdeung in 1993, resulting in shoreline advance in a rate of 40 m/yr. Rate of shoreline changes differ both within and between barrier islands and have a tendency to increase eastward. To understand this spatial variability of rate of shoreline changes, it is suggested to make a detailed investigation into the impact of coastal development on hydrodynamic and sedimentary processes.

• Journal of the Korean Geographical Society
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• v.44 no.4
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• pp.481-496
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• 2009

Every coastal area exhibits its own unique landscape owing to the combination of the natural and cultural processes. Coastal barrier islands well show the cultural aspects of American coastal landscapes. Some 47% of barrier island area was occupied by urban and built-up area in New Jersey, while some 5% in Georgia. Tourism-related development is back to in the mid 19C. in N.J. due to the closeness to heavily populated areas such as New York and Philadelphia. Developments without proper understanding the nature of coastal processes caused New Jerseyization, the destruction of the beauty or naturalness. It was mainly due to the lack of growth-control policies and the foresight for the future coast in the processes of legislation. North Carolina's islands experienced an increase of 269% in urbanized acreage between 1956 and 1976. However, N.C. exercised her wisdom to recover the naturalness of the coastal environs: all engineering structures are banned on the beaches. Nine out of 13 barrier islands in Georgia exist in the wilderness condition owing to her unique history. The remaining islands still experienced the least development. After the Civil War most of Georgian islands were owned by rich families and maintained as wilderness. In the 1970s most of the uninhabited islands were sold or donated to research institutes or governmental agencies.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.18-18
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• 2020

금강하구와 같이 막힌 대형 하구는 근본적으로 복잡한 물리화학적 프로세스와 다양한 이해당사자간의 갈등 때문에 단편적인 접근으로는 관리의 한계가 있을 수밖에 없는 환경이다. 더욱이 하굿둑의 갑문을 열어 하구순환을 복원하는 해수유통 사업은 그 자체가 가지는 환경적 효용성의 확인과 기존 용수이용 체계의 전면적 변화와 관련된 상당한 비용이 요구된다는 면에서 특별한 논란이 되어왔다. 본 연구는 해수유통으로 인한 금강 하구해역의 수리, 수질, 퇴적 및 생태 등 다양한 환경적 변화를 집중적인 현장 조사 및 통합 모델링을 통해 정량적으로 예측하고 이를 지역 이해당사자 논의 체계인 금강하구해역정책협의회에 제공함으로써 해수유통과 연관된 이해당사자 간 갈등을 완화하고 과학적 자료에 근거한 정책결정을 지원하기 위해 수행되었다(과학-정책의 통합). 조사연구는 하굿둑 갑문 개방에 따른 다양한 시나리오별로 해수유통으로 인한 영향을 하구해역(하굿둑의 바다 쪽 해역)과 하구호(하굿둑의 하천 쪽 담수역)에 미치는 영향을 검토하였다(하천-하구호-연안해역의 공간적 통합). 시나리오는 하구해역정책협의회의 요구사항을 반영하여 개발되었고, 시나리오별 영향파악은 수리(조석 및 파랑 포함), 퇴적물 이동 및 수질은 Delft3D모델을, 유역으로부터의 유량 및 오염물질 부하량은 분포형 비점모델인 STREAM을, 김양식과 이매패류 생산량을 추정하는 생태모델은 통계기반의 포인트 모델을 통해 이루어졌다(수리-퇴적-수질-생태계 모델의 통합). 시나리오 분석결과, 상시 해수유통을 제외한 대부분의 하굿둑 부분 개방 시나리오에서는 하구해역에 미치는 영향이 제한적으로 나타나는 것으로 예측되었다. 이는 하굿둑 부분 개방에 따른 담수방류량 및 이에 대응하는 해수의 유동패턴이 현재와 크게 달라지지 않음을 반영한다. 반면 하구호에 대한 영향은 하구해역에 비해 하굿둑 갑문 운영시나리오에 따라 상대적으로 민감하게 변화되는 것으로 예측되었다. 갑문의 부분 개방을 통해 하구호의 수위를 현재 대비 5cm~50cm 변화시켰을 때 1psu 염분의 저층에서의 침투거리는 하굿둑 상류 6km~18km 정도로 예측되었고 갑문 개방에 의해 염분 침투 거리의 조절이 가능할 것으로 나타났다. 단, 사용된 통합모델은 수년간의 검보정 과정을 반복적으로 수행하여 예측의 정확도를 지속적으로 개선하였지만, 모델운영 자체의 불확실성을 고려할 때 실제 해수유통을 위해서는 시범개방을 통해 모델 예측의 결과를 확인할 필요가 있다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.1
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• pp.40-50
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• 2011

We study the characteristic and total flux of non-point pollutants such as total suspended solids (TSS), chemical oxygen demand (COD), dissolved nutrients, total phosphorus (TP) and total nitrogen (TN) in the storm water runoff from urban streams and sewer outlets of Banweol Industrial Complex around Shihwa Lake. The concentrations of non-point pollutants were generally increased with increasing of the duration and intensity of rainfall. Mean TSS concentration of Ansan stream was higher than that of sewer outlets but mean concentrations of COD, TP and TN were approximately 2~5 times higher of sewer outlet than of urban stream. TSS showed statistically positive relationships with COD and TP but it had negative correlation with dissolved nutrients. There was a significant correlation between total flux of non-point pollutants in the storm water runoff and total basin area of each sewer outlet, showing that the highest runoff flux was observed at 3rd sewer outlet which represents the largest basin area from Banweol industrial complex. Total runoff fluxes for TSS, COD, TP and TN in this study were 187,536 kg, 17,118 kg, 922 kg, 13,519 kg, respectively. Given the basin area of sewer outlet in Banweol industrial complex which corresponds only 3% from total catchment area around Shihwa Lake, enormous amount of non-point pollutants will be entered into Shihwa Lake without any treatment. It is necessary to manage and reduce of various non-point sources and pollutants because the runoff of nonpoint pollutants during storm events should be deteriorating the water quality of Shihwa Lake. Our results provides useful informations on the development of best managements practices (BMPs) for effective implementation of total pollution loads management system of Shihwa Lake.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.434-449
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• 2019

In this study, we develop a new cross-shore sediment module which takes the effect of infra-gravity waves of bound mode, and boundary layer streaming on the sediment transport into account besides the well-known asymmetry and under-tow. In doing so, the effect of individual random waves occurring during the unit observation period of 1 hr on sediment transport is also fully taken into account. To demonstrate how the individual random waves would affect the sediment transport, we numerically simulate the non-linear shoaling process of random wavers over the beach of uniform slope. Numerical results show that with the consistent frequency Boussinesq Eq. the application of which is lately extended to surf zone, we could simulate the saw-tooth profile observed without exception over the surf zone, infra-gravity waves of bound mode, and boundary-layer streaming accurately enough. It is also shown that when yearly highest random waves are modeled by the equivalent nonlinear uniform waves, the maximum cross-shore transport rate well exceeds the one where the randomness is fully taken into account as much as three times. Besides, in order to optimize the free parameter K involved in the long-shore sediment module, we carry out the numerical simulation to trace the yearly shoreline change of Mang-Bang beach from 2017.4.26 to 2018.4.20 as well, and proceeds to optimize the K by comparing the traced shoreline change with the measured one. Numerical results show that the optimized K for Mang-Bang beach would be 0.17. With K = 0.17, via yearly grand circulation process comprising severe erosion by consecutively occurring yearly highest waves at the end of October, and gradual recovery over the winter and spring by swell, the advance of shore-line at the northern and southern ends of Mang-Bang beach by 18 m, and the retreat of shore-line by 2.4 m at the middle of Mang-Bang beach can be successfully duplicated in the numerical simulation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.2
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• pp.70-80
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• 2011

Estuarine ecosystem responds sensitively to natural and anthropogenic perturbations. lt is necessary to identify the direction of the change when the perturbation occurs as well as to understand the structure and functioning of estuarine ecosystem for a proper management of the area. In this study, the estuarine habitats were classified into different ecological districts so as to the switch from one district to another district could be related to the environmental change due to the perturbations. Total 16 ecological districts was defined according to the presence of barrage, salinity and vegetation characteristics. The defined ecological districts were applied to small estuaries in Goseong bay, south sea of Korea (Baedun, Guman, Maam, Goseong) to distinguish different regions which might have characteristic bottom topography, inclinations of river bottom, sediment characteristics, salinity structure and area of vegetation. Total 7 out of 16 ecological district was identified in this region; NFB (natural, fresh, bare), NHB (natural, high salinity, bare), NLV (natural, low salinity, vegetated) in natural (without barrage) estuaries and CFB (closed, fresh, bare), CFV( closed, fresh vegetated), CLV (closed, low salinity, vegetated), CHB (closed, high salinity, bare) in closed (with barrage) estuary. A comparison of environmental factors and biota between CHB and CLV demonstrated the effect of barrage on estuarine ecosystem. The height and sediment characteristics of CHB and CLV were similar but the average salinity was lower in CLV than in CHB due to the barrage, which produced favorable condition for the Phragmites australis in CLV. Information regarding the ecological districts in various sizes and location could be useful for predicting the ecosystem change due to natural and anthropogenic perturbations and for preparing management actions.