• Title/Summary/Keyword: 해저지형

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수정 Boussinesq 방정식을 이용한 Bragg 반사

  • 조용식;이종인;이봉희
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1996.10a
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    • pp.172-175
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    • 1996
  • 외해로부터 해안선부근으로 이동하는 파랑은 해저협곡 및 대륙붕과 같은 해저지형의 변화, 방파제와 같은 해안구조물과의 상호간섭 및 파랑상호간의 비선형효과 등에 의해 굴절, 회절, 천수 및 쇄파 등과 같은 변화를 경험한다. 파랑변형의 원인이 되는 여러 변화 중에서 흥미 있고 연구할 가치가 있는 물리적 현상중의 하나는 Bragg 반사이다. (중략)

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과학기술, 그 뿌리와 현주소 - 해양학편(중)

  • Park, Yong-An
    • The Science & Technology
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    • v.32 no.10 s.365
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    • pp.78-80
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    • 1999
  • 20세기 중반인 세계2차대전중에 수집된 미국ㆍ독일ㆍ영국해군의 해양관측자료들은 대서양 등 3대 해양의 현상과 신비를 파악하는데 크게 기여했다. 미국을 비롯한 선진 해양국가들은 대형 탐사선으로 해저지형과 해저층세 또는 판구조원리를 연구하여 20세기 후반의 해양학은 깊은 바다 해수의 물리적 특성과 생물순환의 비밀까지 규명할 수 있게 되었다.

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A study on the Development of Virtual Aquarium System (가상현실 기법을 이용한 가상수족관 시스템 개발)

  • 김기호;박재형;안재우;김동현
    • Proceedings of the ESK Conference
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    • 1996.10a
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    • pp.166-170
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    • 1996
  • 가상현실(VR) 기법을 이용한 가상 수족관 시스템은 3차원 형상 모델링 작업을 통하여 해저지형과 여러 종류의 물고기들을 가상공간에 위치시켜서 기본적인 가상 수족관을 제작하고, 제작된 가상 수족관 에서 자연스럽게 움직이는 물고기의 모습을 표현하는 연구를 통하여 가상 수족관 시스템을 완성하였다.

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Bathymetric changes off the sea south of Jinwoo-do Island in the Nakdong River estuary (낙동강 하구역 진우도 남측 해역의 해저지형 변화)

  • Park, Bong-woon;Kim, Sung-bo;Kim, Jae-joong;Kim, Ki-cheol
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.1
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    • pp.69-74
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    • 2016
  • Bathymetric changes were studied in the southern sea off the Jinwoo-do Island, which is one of the deltaic barrier islands surrounding the Nakddong river estuary. In this study, 16 bathymetry data sets were obtained from June 2006 to April 2015. Two narrow channels, the one lying between Jinwoo-do and Shinja-do, and the other one lying between Nulcha-do and Jinwoo-do extended into the eastern and western parts of the study area, respectively. The eastern extension of the channel contained a passage of mixed estuarine waters of seawater and river water discharged from the Nakdong river barrier and the west Nakdong River. The western channel connected the Nakdong River estuary with the Busan New Port via a connecting pier. Total volumetric changes of sediments in study area and discharge flow of the Nakdong river barrier were analyzed. Bottom topographical changes occurred mainly in the eastern extension of the channel. These changes were initially characterized by gradual erosion or deposition followed by rapid restoration. The total volume of sediment gradually increased from June 2006 to March 2013, but experienced a sudden decrease in October 2013 because of typhoon Danas. Few fluctuations were observed from October 2013 to April 2015. Analysis of the cross-sectional bathymetry of the north-south direction showed that the deepest point of the eastern channel moved 100-130 m westward and 200 m northward between June 2006 and April 2015.

Analysis of Brags Reflection of Cnoidal Waves with Boussinesq Equations (Boussinesq방정식을 이용한 크노이드파의 Brags반사 해석)

  • 조용식;정재상;이종인
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.4
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    • pp.274-281
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    • 2002
  • Numerical analysis for the Bragg reflection due to a sinusoidally and a doubly-sinusoidally varying seabeds was performed by using a couple of ordinary differential equations derived from the Boussinesq equations. Incident waves are a train of cnoidal waves. The effects of the dispersion and shape of seabed were investigated. It is shown that the reflection of a sinusoidally varying seabed is enhanced by increasing the dispersion and the amplitude of a seabed. The reflection of waves over a doubly-sinusoidally varying seabed can also be enhanced by increasing the amplitude of seabed decreasing the difference of wave numbers of seabed components.

Characterisitics of Wave-Induced Current in the vicinity of Wolpo Harbor (월포항 인근해역에서의 해빈류 특성)

  • Lee, Seong-Dae
    • Journal of Korea Water Resources Association
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    • v.33 no.6
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    • pp.661-669
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    • 2000
  • The accurate prediction of wave-induced currents is indispensible to analyze the beach deformation due to the sediment transport or dispersion in the surf zone, which often gives rises to serious environmental problems in the coastal region. Although many numerical models have been suggested up to now, it is not easy to properly simulate wave-induced currents, in particular, over a complex topography. In order to solve these problems, we have to understand the mechanism of wave transformation and wave-induced currents, to compare results numerical models with those of field measurements, and to find the validity and the applicability of them. And, also the validity of the model has been confirmed by the field investigation.

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Bragg Reflection of Long Waves Generated by Short Wave Groups on a Sloping Beach (경사지형에서 파군에 의해 생성된 장파의 Bragg 반사)

  • Jung, Jae-Sang;Cho, Yong-Sik
    • Journal of Korea Water Resources Association
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    • v.36 no.3 s.134
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    • pp.413-422
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    • 2003
  • Numerical analysis for the Bragg reflection due to sinusoidally varying seabeds tying on a sloping beach was performed by using a couple of ordinary differential equations derived from the Boussinesq equations. Incident waves were wane groups generated by two short waves with slightly different phases. Effects of the slope of a seabed to the reflection were investigated in detail. It is shown that the reflection of long waves enhanced by increasing the slope of a seabed. This phenomenon caused by increase of wave amplitude due to increase of nonlinearity and shoaling.

A Numerical Modeling Study on the Seasonal Variability in the Gulf of Alaska (알라스카 만의 계절변화에 대한 수치모형 실험)

  • Bang, In-Kweon;Zygmunt Kowlik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.3
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    • pp.309-325
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    • 1994
  • Ocean circulation in the Gulf of Alaska is remarkably constant throughout the year despite of being forced by one of the largest seasonal wind stresses in the world. To explain the small seasonal changes in the transport of Alaska Stream. a set of numerical models is employed. First a diagnostic approach is applied to reproduce circulation from the observed density structure. The results reveals the very small seasonal changes in the Alaska Stream transport. Next a series of the prognostic models is used: a barotropic model. a flat bottom baroclinic model, and baroclinic model with topography. These models reveal the influence of topography and baroclinicity on the ocean's response to the seasonal wind forcing. The intercomparisons of the various model results suggest that the seasonal response of the baroclinic ocean is primary barotropic and the resultant barotropic circulation is weakened by the scattering effect of the bottom topography.

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Geophysical survey around East Sea Research Institute (KORDI) using multi-beam and shallow seismic survey (다중빔 음향측심기 및 천부탄성파 탐사를 이용한 동해연구소 주변 지구물리조사)

  • Jeong, Eui-Young;Kim, Chang-Hwan;Lee, Seung-Hun;Kim, Ho;Park, Chan-Hong
    • 한국지구물리탐사학회:학술대회논문집
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    • 2008.10a
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    • pp.185-190
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    • 2008
  • Geophysical survey were investigated in the offshore around East Sea Research Institute, Korea Ocean Research and Development Institute (Jukbyeon-myun, Uljin-gu, Gyeongsangbuk-do, Korea). The surveys were conducted aboard the R/V Jangmok in 2008 using a hull-mounted EM 3002 multi-beam echosounder. Precise bathymetry and seabed images were obtained using multi-beam and thicknesses of sedimentary layer were found through seismic survey. Submarine topography deepens parallel to the coastline to -60 m and rock mass distributed in the southeast of study area. By finding the thickness of sedimentary layer through seismic survey, a sedimentary thickness on the study area was established. Futhermore, monitoring data of bathymetry, substructure and sedimentary environment will be secured through successive geophysical investigation.

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A Study of Habitat Environment Mapping Using Detailed Bathymetry and Seafloor Data in the Southern Shore of the East Sea(Ilsan Beach, Ulsan) (정밀 해저지형 및 해저면 자료를 활용한 동해 남부 연안(울산 일산해변) 생태계 서식지 환경 맵핑 연구)

  • Choi, SoonYoung;Kim, ChangHwan;Kim, WonHyuck;Rho, HyunSoo;Park, ChanHong
    • Economic and Environmental Geology
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    • v.54 no.6
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    • pp.717-731
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    • 2021
  • We analyzed the characteristics of the habitat environment for the Seonam study area in Ulsan, the southern shore of the East Sea using bathymetry and seafloor environment data. The depth of the study area ranges from about 0 m to 23 m. In the west of the study area, the water depth is shallow with a gentle slope, and the water depth becomes deeper with a steep slope in the east. Due to the right-lateral strike-slip faults located in the continental margin of the East Sea, the fracture surfaces of the seabed rocks are mainly in the N-S direction, which is similar to the direction of the strike faults. Three seafloor types (conglomeratic-grained sandy, coasre-graiend sandy, fine-grained sandy) and rocky bottom area have been classified according to the analyses of the bathymerty, seafloor image, and surface sediment data. The rocky bottom areas are mainly distributed around Seaoam and in the northern and southern coastal area. But the intermediate zone between Seonam and coastal area has no rocky bottom. This intermediate area is expected to have active sedimentation as seawater way. The sandy sediments are widely distributed throughout the study area. Underwater images and UAV images show that Cnidarians, Brachiopods, Mollusks are mostly dominant in the shallow habitat and various Nacellidae, Mytilidae live on the intertidal zone around Seonam. Annelida and Arthropod are dominant in the sandy sediments. The distribution of marine organism in the study area might be greatly influenced by the seafloor type, the composition and particle size distribution of the seafloor sediments. The analysis of habitat environment mapping with bathymetry, seafloor data and underwater images is supposed to contribute to the study of the structure and function of marine ecosystem.