• Title/Summary/Keyword: Coastline

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A Hydraulic Experiment Using Artificial Seaweed for Coastal Erosion Prevention (인공식생을 이용한 해빈침식방지에 관한 수리실험)

  • Kim, Beom Mo;Jeon, Yong Ho;Yoon, Han Sam
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.19 no.4
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    • pp.266-273
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    • 2016
  • Two-dimensional hydraulic experiments were performed to assess the impact of artificial seaweed on wave energy attenuation, and coastal erosion prevention. In this experimental study, erosion geometry and wave reflection coefficients were determined for normal and stormy incident waves, with and without artificial seaweed. The coastline of beaches without artificial vegetation was observed to retreat, and the longshore bar height increased in normal and stormy conditions. Through the introduction of artificial seaweed (of widths 0.8 m, and 1.6 m), the coastline was found to advance in the offshore direction due to material deposition. From these results, it is shown that artificial seaweed alters the cross-section of beaches, such that it is possible to prevent coastline erosion.

On the Characteristics of the Water Quality Changes due to the Development Phases of Pusan Port (부산항의 개발단계별 수질환경변동특성에 관한 연구)

  • 고영찬;김종인;류청로
    • Journal of Ocean Engineering and Technology
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    • v.14 no.3
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    • pp.11-19
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    • 2000
  • This study aims to examine the characteristics of the water quality variation in relation to the change of water exchange rate with respect to the development phases of the Pusan port. To clarify the characteristics, water exchange caused by the variations of coastline shape and water surface area was examined by the numerical experiments using the Lagrangian particle tracking model based on 2-D shallow water equation. As the results of numerical experiments, it was proved that the water exchange in the Pusan port was decreased mainly due to the port development and the breakwaters construction. During the port development phases from 1875 to 1998, 35% of the sea-space in the port had decreased to make hinterland spaces. This resulted in the loss of wet-land and coastline change as well as decrease of the water exchange rate at the sea side. The city population in that period had rapidly increased from several thousands to 4 millions, resulting in the large discharge of sewages into the port area. Under the these environmental conditions, it can be clearly said that the water quality in the Pusan port is sensitively affected by the discharge of urban sewages decrease of the water exchange rate in relation to port and urban developments. In the study, the temporal changes of water quality were discussed with respect to the port development phases. It was clear that the water quality wad controlled by the exchange rate change under the port development as well as the input impact into the port from the urbanized city area. To make clean sea of the Pusan port, it is suggested that the sewage control, the water exchange and coastline control should be systematically checked under the concept of eco-friendly development and environmental management.

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Qualitative Analysis of Coast Topographic Using RTK-GPS (RTK-GPS 측량을 이용한 해안지형의 정성적 분석)

  • Kim, Yong-Suk;Lee, Jae-One
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.2 s.40
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    • pp.77-85
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    • 2007
  • According to the survey data during the Japanese Occupation Period, the length of South Korea's coastline is about 11,542 km, including the coastlines of land and islands. It will be very expensive and time-consuming to revise/renew accurately this coastline data through site survey, it will cost great money and time. Also, various development projects such as reclamation works on public waters, constructions of ports/harbors, etc. are frequently changing the coastal areas and coastlines, causing many renewal projects on coastal maps. For such reason, appropriate alternatives for site survey are necessary. This paper demonstrate the utilization of RTK-GPS survey data, qualitative analysis and 3D topographic analysis for extracting the change in five coastal areas (Songjeong, Haeundae, Kwanganri, Songdo and Dadaepo). The local experimental areas subjected for this research were limited to five coastal areas near Busan.

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The study of masan barber's coastal line change during 100years

  • Choi, Chul-Uong;Kim, Young-Seop;Cho, Sung-Hwan
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.273-273
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    • 2002
  • Masan barber was situated in S.Korean southern central coast. And it is contributing greatly in S.korea's economy development to international trading port of Heaven's blessing that possess natural, geographical situation. Also, because there are Masan free tax area and chanwon heavy industrial complex, sachon air industrial complex etc. on back, it is important permanency in our country. Specially, because inland transport routes such as southern highway, Guma highway and national road system are developed well, the importance is very high. Masan harbor 1899.05.01 be that opened, the 1st and 2nd (central pier) was build 1938∼1944 year, and the 3rd pier was 1973∼1978 year. the 4th pier was 1974∼1983 year, 5th pier was 1984∼1988, 6th pier (west pier) was 1985∼1992 year. it was developed over 100 years. But, it did great many harbor and bay development of last 100 yens but research about coastline change and seashore reclamation is insufficient. Therefore, this research executed research about coastline change of Masan bay of last 100 years, In this study, we analyzed aerial photographs and tide data for the past 100 years using digital aerial photo analysis and GIS techniques for each 3-year interval. We abstracted beach DEM (digital elevation model) and ortho aerial photographs, and conducted a space analysis. As a result, we were able to identify changes in the area As a result, we drew 10 years cycle coastline change of Masan bay. and we can detect bay coastal line change and calculate refill rate.

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The effect of typhoon translation speed and landfall angle on the maximum surge height along the coastline

  • Qian, Xiaojuan;Son, Sangyoung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.153-153
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    • 2021
  • Storm Storm event is one of major issues in South Korea due to devastating damage at its landfall. A series of statistical study on the historical typhoon records consistently insist that the typhoon translation speed (TS) is on slowdown trend annually, and thus provides an urgent topic in assessing the extreme storm surge under future climate change. Even though TS has been regarded as a principal contributor in storm surge dynamics, only a few studies have considered its impact on the storm surge. The landfall angle (LA), another key physical factor of storm surge also needs to be further investigated along with TS. This study aims to elucidate the interaction mechanism among TS, LA, coastal geometry, and storm surge synthetically by performing a series of simulations on the idealized geometries using Delft3D FM. In the simulation, various typhoons are set up according to different combinations of TS and LA, while their trajectories are assumed to be straight with the constant wind speed and the central pressure. Then, typhoons are subjected to make landfall over a set of idealized geometries that have different depth profiles and layouts (i.e., open coasts or bays). The simulation results show that: (i) For the open coasts, the maximum surge height (MSH) increases with increasing TS. (ii) For the constant bed level, a typhoon normal to the coastline resulted in peak MSH due to the lowest effect of the coastal wave. (iii) For the continental shelf with different widths, the slow-moving typhoon will generate the peak MSH around a small LA as the shelf width becomes narrow. (iv) For the bay, MSH enlarges with the ratio of L/E (the length of main-bay axis /gate size) dropping, while the greatest MSH is at L/E=1. These findings suggest that a fast-moving typhoon perpendicular to the coastline over a broad continental shelf will likely generate the extreme storm surge hazard in the future, as well as the slow-moving typhoon will make an acute landfall over a narrow continental shelf.

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An Analysis of the Coastal Topography and Land Cover Changes in the Haeundae Beach (해운대 해수욕장의 해안지형 및 토지피복 변화 분석)

  • Yang, Ji-Yeon;Choi, Chul-Uong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.1
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    • pp.101-115
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    • 2006
  • As coastal erosion is increasing sharply because of sudden changes in the natural environment and increases in artificial development, the problem of coastal erosion become an important issue, socially and economically. To building the data which needed to grasp the situation and find a solution, we need the monitoring system for long-term. In this study, we analyzed the coastal topography and land cover changes in the Haeundae Beach during 60 years. The Haeundae Beach is the most famous beach in the country and coastal erosion are going on. First, we analyzed the change of coastal topography by calculated the coastline and area of the beach using aerial photos during 60 years. We extracted the coastline by digitized on aerial photo and corrected the height of tide level using sounding and GPS survey data. And we computed the area of beach and analyzed the change of area during 60 years. Second, we analyzed the change of land cover using landcover map. We made the detailed landcover map by on-screen digitizing and estimated the soil loss for the area nearby Haeundae Beach. As a result, we could see that the coastline get nearer to land and the area of beach has been reduced in general. We think that interception of sand supply by the development is the artificial cause of coastal erosion. The result of this study would be useful in long-term coastal monitoring and to analyze the cause of coastal environment change. We expect that the result is available on the coastal information system.

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Association between Metabolic Syndrome and Participation in Clean-up Work at the Hebei Spirit Oil Spill (허베이 스피리트호 원유유출시 방제작업과 대사증후군의 연관성)

  • Lee, Ik-Jin;Jang, Bong-Ki;Lee, Jong-Wha;Son, Bu-Soon;Cheong, Hae-Kwan;Ha, Mina;Choi, Young-Hyun;Park, Myungsook
    • Journal of Environmental Health Sciences
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    • v.41 no.5
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    • pp.335-348
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    • 2015
  • Objectives: We aimed to assess the risk of metabolic syndrome one year after the 2007 Hebei Spirit oil spill in Taean, Korea among people exposed to spilt oil during clean-up work. Methods: A total of 6,923 adults, including 3,019 males and 3,904 females, participated in the study. Health examinations and blood tests (total cholesterol, triglycerides, HDL, fasting blood sugar) were performed. A logistic regression model adjusting for age, gender, smoking history, drinking history, income, education, and marital status was used to estimate the risk of metabolic syndrome associated with the level of oil spill exposure. Results: The prevalence of metabolic syndrome was 24.9% among males and 18% among females. Compared with people living within 20 km of the coastline, the risk of metabolic syndrome among people living within 0.8 km of the coastline was significantly higher (male OR=1.696, 95% CI=1.320-2.178, female OR=1.992, 95% CI=1.549-2.561), including a significant dose-response relationship for distance from early contaminate coastline (p<0.001). The risk of metabolic syndrome was higher according to the increase of duration of cleaning work. The risk of metabolic syndrome among people who participated in the clean-up work for more than 116 days, compared with people who participated in the cleaning work for or less 14 days, was significantly higher (male OR=1.845, 95% CI=1.448-2.353, female OR=1.752, CI=1.378-2.228), with a significant dose-response relationship for days of clean-up work (p<0.001). Conclusion: This study showed that there is a significant association between exposure to the oil spill during the clean-up work, distance from early contaminate coastline and the risk of metabolic syndrome in a doseresponse manner.

The Study of Coastal Change from Using Ortho Aerial Photo and Hydrographic Survey : the Parcel under the Sea (정사항공사진과 해양조사측량을 이용한 해안선변화탐지에 관한 연구 : 포락지 중심으로)

  • Choi, Chul-Eung;Seo, Yeong-Chan;Yang, Ji-Yeon;Park, So-Yeong;Kim, Youn-Soo
    • 한국지형공간정보학회:학술대회논문집
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    • 2004.10a
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    • pp.167-173
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    • 2004
  • The erosion(or sediment) reaches very serious level due to the aftermath by the imprudent reclamation on the coast. Continuous studies for long on coastline erosion may be warranted and possible countermeasures proposed because the change of the coastline has been progressed slowly for a long period of time in a wide area. Many experts anticipate that the global sea level's average increase by 19-35 cm due to global warming may certainly have an effect on the coastal erosion throughout the world. Thus, a more rigorous study on the causes of changing coastlines is particularly proposed to find ways to counteract any possible threats against coastal environments. In this study, Ortho aerial photo and hydrographic survey datum were utilized to quantitatively analyze coastal erosion and sediment patterns. This paper also seeks to prove that a parcel under the sea occurred due to relatively significant changes to the coastline. We created Ortho aerial photo using aerial photos taken each decade ('81, '93, '00), overlaid them onto a cadastral registration map, and calculated each amount of erosion and sediment while accounting for the tide level and without considering it. As the result of this study, we could propose that the methods of Ortho aerial photo and the marine observation datum were the effective ways of change detection in erosion, sediment, and artificial reclamation of the coastline for a long time.

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Inundation simulation in a urban drainage basin considering tidal stage effect (조위의 영향을 고려한 도심지 배수유역에서의 범람모의)

  • Kim, Dae Geun;Choi, Kyung Soon;Koh, Young Chan
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.6
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    • pp.711-717
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    • 2009
  • In this study, SWMM model is used to reproduce the main storm sewer system located in the Nae-Hang drainage basin of the Mokpo city and keep track of flood discharge. Given the outlet of the reaches border the coastline, this paper has taken the dual-drainage approach to perform inundation simulation, considering both the overflows and inflows at the manholes of the sewer system, and at the same time, taking the impacts of tidal stage into consideration. The following conclusions are reached in this study: First, when planning lowland sewer system alongside the coastline or the riverside, the tidal stage or flood stage need to be considered in the planning and design processes. Second, an analysis that fails to consider overflow and inundation at the manholes may overestimate inundation depth of the flooded area. In other words, in order to estimate flood discharge and flood stage in a lowland storm sewer system, it is desirable to analyze the conveyance capacity of storm sewer system and simulate overflow and inundation at the manholes at the same time.

Estimation of Coastal Terrain Differences by time-series using GSIS and The chart (GSIS를 이용한 해안 지형의 시계열 변화량 추출)

  • 양인태;한성만;최승필
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2002.04a
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    • pp.219-228
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    • 2002
  • Because western sea on the shore development is threatening sea ecosystem by decrease of silt and large size land-reclamation work by industrialization causes surrounding weather change and sea change, generate much changes bottom of the sea topography and coastline. Also, is influencing to route for safe entry into port of ship, departure. Therefore, this research did 0m boundary line, anxiety 2m line which appear to coastline of land portion and the border of silt using sea base level of lowest low tone side that is base line that appear because of sea waves to basis data numerical value Tuesday, numerical value by divide drawing that is changed to 4 area and analyze change degree of new airport construction and new town development, seashore by western sea district along the coast development of tide embankment construction and so on and bottom of the sea recognize.

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