• Title/Summary/Keyword: coastal sea

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Adaptive Sea Level Prediction Method Using Measured Data (관측치를 이용한 적응적 조위 예측 방법)

  • Park, Sang-Hyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.5
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    • pp.891-898
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    • 2017
  • Climate changes consistently cause coastal accidents such as coastal flooding, so the studies on monitoring the marine environments are progressing to prevent and reduce the damage from coastal accidents. In this paper, we propose a new method to estimate the sea level which can be applied to the tidal sensors to monitor the variation of sea level. Existing sea level models are very complicated and need a lot of tidal data, so they are not proper for tidal sensors. On the other hand, the proposed algorithm is very simple but precise since we use the measured data from the sensor to estimate the sea level value in short period such as one or two hours. It is shown by experimental results that the proposed method is simple but predicts the sea level accurately.

Numerical Simulation of Advection and Diffusion using the Local Wind Model in Pusan Coastal Area, Korea (부산 연안역에서의 국지풍모델을 이용한 이류확산 수치모의)

  • 김유근;이화운;전병일
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.1
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    • pp.29-41
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    • 1996
  • The two-stage numerical model was used to study the relation between three-dimensional local wind model, advection/diffusion model of random walk method and second moment method on Pusan coastal area. The first stage is three dimensional time-dependent local wind model which gives the wind field and vertical dirrusion coefficient. The second stage is advection/diffusion model which uses the results of the first stage as input data. First, wind fields on Pusan coastal area for none synoptic scale wind showed typical land and sea breeze circulation, and convergence zone occured at 1200LST in northern of domain, in succession, moved northward of domain. Emissions from Sinpyeong industrial district were trasnported toward the inland by sea breeze during daytime, and reached the end part of domain about 1800LST. During nighttime, emissions return to sea by land breeze and vertical diffusion also contributes to upward transport. In order to use this model for forecast of air pollution concentration on the Pusan coastal area, it is necessary that computed value must be compared with measured value and wind fields model must also be dealt in detail.

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Numerical Simulation of Ozone Concentration using the Local Wind Model in Pusan Coastal Area, Korea (부산연안역에서 국지풍모델을 이용한 오존농도의 수치모의)

  • Jeon, Byung-Il;kim, Yoo-Keun;Lee, Hwa-Woon
    • Journal of Environmental Science International
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    • v.6 no.4
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    • pp.335-350
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    • 1997
  • Numerical simulations of photochemical air pollution (CBM: Carbon-Bond Mechanisms under a theoretical three-dimensional local wind system are carried to clarify the fundamental characteristics of the effects of local wind on photochemical air pollution. According to the AWS data of Pusan coastal area and KMA, the surface wind of Pusan during summertime showed a very remarkable land and sea breeze circulation. The ozone concentration distribution using local wind model showed that high ozone concentration zone near coastal area moved toward inland In the afternoon. This change implies a sea breeze Increases the ozone concentration, but a land breeze decreases it in Pusan coastal area.

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Hydraulic Characteristics of water affinity sea-wall block (환경친화형 친수호안(親水護岸)블록 수리특성)

  • Han, Jea-Myung;Oh, Young-Min
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.2
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    • pp.179-182
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    • 2007
  • In this study hydraulic model experiment was conducted to identify the performance of newly developed water affinity sea-wall block to keep the coastal line from eroding and supply water affinity space by reflection coefficient and safety. In the result, the block is applicable to the field.

A Status of Distributions and its Characteristics of the Geomorphological and Geological Landform Resources in Taeanhaean National Park (태안해안국립공원 해안지형과 지질 자원의 분포 현황과 특성)

  • Seo, Jong Cheol
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.4
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    • pp.97-106
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    • 2019
  • This study aims to investigate geomorphological and geological landscapes in the Taeanhaean National Park to ensure they are well-preserved. This study discovered 390 geomorphological and geological landform resources distributed in the coastal zone of Taeanhaean National Park. Representative geomorphological and geological landforms include : sea cliffs, sea caves, wave-cut platforms, sea-stacks, pebble beaches, sand beaches, tidal flats, coastal dunes, coastal dune wetlands and folds (or micro folds) landforms. Deposition landforms are developed more and erosion and weathering landforms are less on the land zone than island zone. These landform resources vary from district to district and can be developed for geo-tourism resources. Combined efforts from the Taeanhaean National Park authorities and residents are essential to manage ecological programs using geomorphological and geological resources.

Improvements in the simulation of sea surface wind over the complex coastal area- I : Assessment of current operational model (복잡 해안지역 해상풍 모의의 정확도 개선- I : 현업모델의 평가)

  • Bae Joo-Hyun;Kim Yoo-Keun;Oh In-Bo;Jeong Ju-Hee;Kweon Ji-Hye;Seo Jang-Won
    • Journal of Environmental Science International
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    • v.14 no.7
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    • pp.657-667
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    • 2005
  • In this study, we focused on the improvements in the simulation of sea surface wind over the complex coastal area. MM5 model being currently used to predict sea surface wind at Korea Meteorological Administration, was used to verify the accuracy to estimate the local wind field. A case study was performed on clear days with weak wind speed(4 m/s), chosen by the analysis of observations. The model simulations were conducted in the southeastern area of Korea during the selected periods, and observational data such as AWS, buoy and QuikSCAT were used to compare with the calculated wind components to investigate if simulated wind field could follow the tendency of the real atmospheric wind field. Results showed that current operational model, MM5, does not estimate accurately sea surface wind and the wind over the coastal area. The calculated wind speed was overestimated along the complex coastal regions but it was underestimated in islands and over the sea. The calculated diurnal changes of wind direction could not follow well the tendency of the observed wind, especially at nighttime. In order to exceed the limitations, data assimilation with high resolution data and more specificated geographical information is expected as a next best policy to estimate accurately the environment of local marine wind field.

Variations and Characters of Water Quality during Flood and Dry Seasons in the Eastern Coast of South Sea, Korea (한국 남해 동부 연안 해역에서 홍수기와 갈수기 동안 수질환경 특성과 변동)

  • Jeong, Do Hyeon;Shin, Hyeon Ho;Jung, Seung Won;Lim, Dhong Il
    • Korean Journal of Environmental Biology
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    • v.31 no.1
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    • pp.19-36
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    • 2013
  • Physiochemical characters of sea waters during summer flood- and winter dry-seasons and their spatial variations were investigated along the coastal area off the eastern South Sea, Korea. Using the hierarchical clustering method, in this study, we present comprehensive analyses of coastal waters masses and their seasonal variations. The results revealed that the coastal water of the study area was classified into six water masses (A to F). During summer season, the surface water was mainly occupied by the coastal pseudo-estuarine water (water mass B) with low salinity and high nutrients and the river-dominated coastal water (water mass C) with low nutrients, respectively. The bottom water was dominated by cold water (water mass D) with very low temperature, high salinity and high nutrients, compared to masses of surface water. Notably, the water mass B, with high concentrations of nutrients (silicate and nitrogen) and low salinity, which is strongly controlled by the water quality of river freshwater, seems to play an important role in controlling the water quality and further regulating physical processes on ecosystem in the eastern coastal area of South Sea. The water mass D (bottom cold water) coupled with a strong thermocline, which exists in near-bottom layer along the western margin of Korea Strait, has a low temperature, pH and DO, but abundant nutrients. This water mass disappears in winter owing to strong vertical mixing, and subsequently may act as a pool for nutrients during winter dry-season. On the other hand, vertically well-mixed water column during the winter season was typically occupied by the Tsushima (water mass E) and the coastal water (water mass F) with a development of coastal front formed in a transition zone between them. These winter water masses were characterized by low nutrient concentration and balance in N/P ratio, compared with summer season with high nutrient concentrations and strong N-limitation. Accordingly, the analysis of water masses will help one to better chemical and biological processes in coastal area. In most of the study area, characteristically, the growth of phytoplankton community is limited by nitrogen, which is clearly different with coastal environment of West Sea of Korea, with a relative lack of phosphorus. It showed the western and the southern coasts in Korea are substantially different from each other in environmental and ecological characteristics.

Long Term Trend of Change In Water Temperature and Salinity in Coastal Waters around Korean Peninsula (한반도 근해 수온 및 염분의 장기변화 추이)

  • Jeong, Hee-Dong;Hwang, Jae-Dong;Jung, Kyu-Kui;Heo, Seung;Sung, Ki-Tach;Go, Woo-Jin;Yang, Jun-Yong;Kim, Sang-Woo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.9 no.2
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    • pp.59-64
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    • 2003
  • The long­term trend and inter­relationship with depth of temperature and salinity in coastal waters of Korea are studied using coastal oceanographic observation and serial oceanographic data measured by National Fisheries Research and Development Institute. Temperature of coastal waters of Korea except south­western sea of Korea where cold water appears to increase in summer. In case of temperature offshore, surface temperature of East Sea increases, the reverse, for 50m and 100m decreases. Temperature in South Sea of Korea increases in whole depth and for the Yellow Sea, surface temperature increases, but for 50m decreases. In case of salinity offshore, surface salinity of East Sea decreases, but for 50m increases. Surface salinity in South Sea of Korea decreases, the reverse, form 50m and 100m increases. salinity in the Yellow Sea decrease in whole depth According to the result of inter­relationship analysis, for temperature relationship coefficients of 50m and 100m in the East Sea and South Sea of Korea is higher, however, for the Yellow sea the inter­relationship between 50m and 100m is lower. In case of salinity, the inter­relationship between surface and 50m, and for the South Sea of Korea, between 50m and 100m, and for the Yellow Sea, between surface and 50m is higher.

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A Study on the Introduction of Impact Assessment System for Coastal Erosion (연안침식영향평가 제도 도입방안 연구)

  • Bum Shik Shin;Hyun Hwa Shin
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.36 no.2
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    • pp.87-93
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    • 2024
  • Recently, the impact of climate change with sea levels rise, abnormal high waves, and continuous construction of artificial structures such as ports and harbors, has led to an increasing trend in coastal erosion. In this study, the scope and method of Environmental Impact Assessment, Utilization of Sea Areas, Disaster Impact Assessment, and Risk Assessment of Coastal Disasters System, which are carried out during development projects and erosion reduction projects carried out on the coast, are analyzed to identify each problem. , we proposed a plan to introduce the Impact Assessment System for Coastal Erosion, which can minimize the impact of coastal erosion by deriving improvement measures.

Fluctuation Characteristic of Temperature and Salinity in Coastal Waters around Jeju Island (제주도 연안 천해역의 수온 · 염분 변동 특성)

  • KO Jun-Cheol;KIM Jun-Teck;KIM Sang-Hyun;RHO Hong-Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.3
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    • pp.306-316
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    • 2003
  • We conducted a time-series analysis of temperature and salinity of sea water around Jeju Island, Korea. Monthly mean temperature and salinity was influenced by precipitation and weather conditions on Jeju as well as by oceanographic conditions of the open sea such as the Tsushima Warm Current and sea water in coastal areas. Salinity of Jeju coastal waters was the highest in April, and it was always over 34.00 psu with tiny fluctuation between December and June. Due to the effects of the Tsushima Warm Current, Jeju coastal waters maintained high salinity and stability. Low salinity and its large fluctuations during summer were closely associated with the China Coastal Water and precipitation in Jeju. The place of the lowest water temperature was the northeast coasts of Jeju (Gimneong, Hado, Jongdalri). In winter, as warmer water of the Tsushima Warm Current appeared in western area of Jeju dwindled flowing along the northern coasts of Jeju area and becoming cool, the lowest water temperature often appeared locally in Gimnyeong and its vicinitly in summer. The Tsushima Warm Current flows into the east entrance of Jeju Strait, but its influence is weak because of geometry and strong vertical mixing due to fast tidal currents.