• 대한원격탐사학회지
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• 제17권2호
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• pp.131-139
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• 2001

Extraction of waterline in tidal flat has been one of the main concerns in the remote sensing of coastal region. This study aimed to define the spectral characteristics of turbid water near the shoreline and to find the appropriate spectrum to delineate the waterline at the inter-tidal flat in the western coast of Korean Peninsula. Spectral reflectance curves were obtained by the field measurements under the diverse condition of water depth and turbidity at the study area in Kyong-gi Bay. Spectroscopy measurements showed that reflectances of the exposed mudflat, shallow turbid water, and normal coastal water were significantly different by wavelength. Shallow water near the waterline showed diverse conditions of turbidity. Spectral reflectance tends to increase as turbidity increases, particularly at the visible and near infrared spectrum. At the middle infrared wavelength, tidal water showed very little reflectance regardless of the turbidity and water depth and was easily disting from the exposed tidal flat. The exact waterline between exposed tidal flat and seawater should be extracted from the image data obtained at the middle infrared wavelength.

• 한국해양환경ㆍ에너지학회지
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• 제7권4호
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• pp.199-206
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• 2004

연안 해역에서의 대규모 외해 구조물의 건설은 구조물 배후의 해안선으로부터 외빈에 이르는 광범위한 영역에서 심각한 해빈변형을 야기학 수 있다. 신 등[2000]과 신과 홍[2004]은 일련의 3차원 이동상 실험을 통하여 외해 구조물 배후의 표사이동 양상을 밝혔으며, 본 연구는 이들 실험 결과를 토대로 복합 3차원 해빈변형모델을 제안한 것이다. 제안된 모델은 3차원 이동상 실험 결과와의 비교를 통해 검정하였으며, 그 결과 외해 구조물 배후에 대한 해안선 측의 톰보로 재현은 물론 외빈대에서의 침식ㆍ퇴적역에 있어서도 좋은 일치를 나타내었다. 또한 대규모 인공섬 건설에 의한 해빈변형문제가 실제 야기되었던 현지 해안에 제안된 모델을 적용하여 그 타당성을 확인하였다.

• 한국대기환경학회지
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• 제25권5호
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• pp.432-449
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• 2009

In this study, the effects of high-resolution land cover on the simulation of near-surface meteorological fields were evaluated in two different coastal regions using Weather Research and Forecasting (WRF) model. These analyses were performed using the middle classification land cover data upgraded by the Korean Ministry of Environment (KME). For the purpose of this study, two coastal areas were selected as follows: (1) the southwestern coastal (SWC) region characterized by complex shoreline and (2) the eastern coastal (EC) region described a high mountain and a simple coastline. The result showed that the application of high-resolution land cover were found to be notably distinguished between the SWC and EC regions. The land cover improvement has contributed to generate the realistic complex coastline and the distribution of small islands in the SWC region and the expansion of urban and built-up land along the sea front in the EC region, respectively. The model study indicated that the improvement of land cover caused a temperature change on wide areas of inland and nearby sea for the SWC region, and narrow areas along the coastal line for the EC region. These temperature variations in the two regions resulted in a decrease and an increase in land-breeze and sea-breeze intensity, respectively (especially the SWC region). Interestingly, the improvement of land cover can contribute large enough to change wind distributions over the sea in coastal areas.

• 한국환경과학회지
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• 제19권6호
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• pp.689-701
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• 2010

The effects of high-resolution wind profiler (HWP) data on the wind distributions were evaluated in two different coastal areas during the study period (23-26 August, 2007), indicating weak-gradient flows. The analysis was performed using the Weather Research and Forecasting (WRF) model coupled with a three-dimensional variational (3DVAR) data assimilation system. For the comparison purpose, two coastal regions were selected as: a southwestern coastal (SWC) region characterized by a complex shoreline and a eastern coastal (EC) region surrounding a simple coastline and high mountains. The influence of data assimilation using the HWP data on the wind distributions in the SWC region was moderately higher than that of the EC region. In comparison between the wind speed and direction in the two coastal areas, the application of the HWP data contributed to improvement of the wind direction distribution in the SWC region and the wind strength in the EC region, respectively. This study suggests that the application of the HWP data exerts a large impact on the change in wind distributions over the sea and thus can contribute to the solution to lack of satellite and buoy data with their observational uncertainty.

• 한국지형학회지
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• 제19권4호
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• pp.59-71
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• 2012

이 연구는 다중시기 원격탐사 영상과 GPS 측량자료 및 입도분석 자료를 이용하여 부산 송정해수욕장의 장기간 해안지형 변화와 원인을 규명하였다. 연구결과, 다중시기 원격탐사 영상 분석에서는 2000년대 초까지 해빈이 전체적으로 안정 상태였으나, 2000년 이후 해안을 따라 호안도로가 건설되면서 전반적으로 침식이 진행되었다. DEM 변화 분석에서는 해빈을 따라 호안도로가 건설된 이후 전체적으로 해빈의 고도가 낮아지고 범의 경사가 급해지는 것으로 보아 침식환경이 우세한 것으로 나타났다. 하지만 세부적으로는 북쪽 해빈지역에서 침식보다는 오히려 퇴적환경이 약간 우세하여 범의 경사가 다소 완만해진 것으로 나타났다. 현장시료의 입도분석에서는 해빈의 남동부 지역(E측선)이 가장 조립화 경향을 보였는데, 이러한 결과는 이 지역이 비교적 외해로부터 유입되는 강한 파랑에너지에 직접적으로 노출되었기 때문이다. 결과적으로 최근 연구지역 내 해빈 침식의 주요 원인은 해안을 따라 건설된 호안도로에 의해 사구로부터의 모래 공급원 차단과 남동쪽 해안에서의 파랑에너지 강화에 따른 세굴 현상 등에 기인한다. 따라서 향후 지형변화나 인위적인 변화가 없을 경우 지속적으로 침식이 될 가능성이 높아 이에 대한 대책수립이 필요하다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권6호
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• pp.939-950
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• 2015

Wave-induced Longshore Sediment Transport (LST) play an important role in the dynamics of the Dhanushkodi sandspit located southeast of Rameshwaram. The LST along the Dhanushkodi coast is studied based on data collected simultaneously in Gulf of Mannar (GoM) and Palk Bay (PB) using directional waverider buoys. The numerical model REF/DIF1 was used to calculate the nearshore waves and the LST rate was estimated using three different formulae. The model validation was done based on the measured nearshore waves using InterOcean S4DW. Numerical model LITPACK was also used for simulating non-cohesive sediment transport and the LITLINE module was used to study the shoreline evolution over 5 years. Low net annual LST along PB (${\sim}0.01{\times}10^6m^3$) compared to the GoM region ($0.3{\times}10^6m^3$) were due to the weak waves. Accretion in the region led to growth of the Dhanushkodi sandspit by 65 m during the period 2010-2015.

• 한국해양공학회지
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• 제6권2호
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• pp.133-142
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• 1992

Beach evolution is of the most important problem is the coastal engineering. Especially, the structure construction through reclamation in the shallow water region nesar the beach will cause many severe problems around the structure. Beach evolution due to the construction of an artificial island in this study was studied using wave transform model and associated of an artificial island in this study was studied using wave transform model and associated sediment transport model. Numerical simulation of the model was applied to the Kwangan beach using the data of waves and shoreline of the area. The combined wave transform model and beach evolution model showed good results. The results show a breakwater will be needed to prevent severe erosion near the eastward Kwangan beach when construction an artificial island in the Suyong Bay. Good results of the study also suggest that the present model can be more widely applied to the prediction of beach evolution.

• 한국대기환경학회지
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• 제8권3호
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• pp.169-178
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• 1992

Dispersion of pollutant in a mountainous area is simulated in a wind tunnel. In the northwest side of the terrain model, the sea level is assumed. Wind from the sea initially confronts hills along the shoreline, a line of large buildings next, and finally a valley between high mountains in the south and in the east. In the northwest wind conditions, severe flow separation occurs in the lee side of hills, even beyond the building area. Pollutant from the buildings is trapped in this region and its concentration is the highest. In the west wind conditions, pollutant from the buildings flows along the hills aslant the main wind direction in this case. Since large valley is located in the downstream, pollutant tends to disperse along the valley.

• 한국해안해양공학회지
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• 제6권1호
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• pp.34-39
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• 1994

흐름수역으로 방류되는 측면부력젵이 연안으로 귀환하는 현상과 희석경향에 대해 실험을 통하여 조사하였다. 실험에서 저흐름의 가로흐름 수역에 warm-water를 등수심으로 측면방류하여 횡방향으로 퍼짐과 수면으로 상승하는 열-plume이 발생하는 부력젵(buoyant jet)이 귀환현상을 얻었다. 실험에서 발생하는 귀환현상과 오염정체지역인 순환영역의 기하학적 구조 및 희석경향을 Froude수(F), 밀도 Froude수(F$_{o}$ ), 부력 특성길이(l$_{b}$)를 이용하여 멱법칙(Power law)으로 표현하였다. 보험결과 귀환현상은 R(U$_{o}$ /U$_{a}$ )<4, F/F$_{o}$ >0.22 일 때 발생하며, 희석은 x/l$_{b}$에 따라 변화하고 순환영역은 속도비(R)에 따라 변화함을 알 수 있었다.

• 한국항만학회지
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• 제14권2호
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• pp.241-249
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• 2000

The amount of municipal water has been increased rapidly up to now and it is necessary to treat and dispose the wastewater effectively. The recent trend of the effluent disposal system, after treatment, show a nearshore discharge which has an outfall with length somewhere between the shoreline discharge and an extended deepwater outfall. There is no universal solution to municipal water treatment and disposal and each case must be examined on its merits and on economic, technical and environmental bases. In this study we focused mostly on the scientific and engineering aspects of ocean disposal through the outfall. For this purpose, we made an investigation to the near-field characteristics of discharged water and made some comparison with the existing experimental results. We also applied it to the Pusan Jungang Effluent Outfall System, which is planned to build in the Gamchun harbour and will be completed in 2011. The model output showed the trajectoral variation of dilution and mixing behavior for three cases of outfall system. Dilution differences have been simulated and found the highest dilution condition under the different displacement of outfall system. On the basis of these outputs it will be proposed the optimum outfall system type and location.