• Title/Summary/Keyword: East Coasts

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Distribution and abundance of wintering raptors in the Korean peninsula

  • Lee, Sangdon
    • Journal of Ecology and Environment
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    • v.36 no.4
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    • pp.211-216
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    • 2013
  • The purpose of this study is to examine distribution and abundance of wintering raptors in Korea during 2000-2007 which is a rare data set for covering large landscape areas. Total 6,643 raptors of 16 species were recorded at 94 different points in west, south and east coasts, and rivers of inland areas all over Korea. During the study period, the most abundant raptors were black vulture (Aegypius monachus, 62.3%), common kestrel (Falco tinnunculus, 11.0%) and common buzzard (Buteo buteo, 10.0%), and these 3 birds were dominant species in inland areas and also considered as resident species except for black vulture. Also, there was a difference among 5 different habitat types. Black vultures were most found in estuaries whereas common buzzard and common kestrel could be found in coastal areas. Presumably raptors prefer reservoirs and estuaries probably due to lower human disturbance in these areas, and management efforts should be concentrated in inland areas for black vulture and coastal areas for common kestrel and common buzzard.

New Records of Cold-Water Corals from Korea

  • Song, Jun-Im
    • Animal Systematics, Evolution and Diversity
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    • v.32 no.3
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    • pp.197-206
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    • 2016
  • Two cold-water coral taxa, Octocorallia in the class Anthozoa and Stylasteridae in the class Hydrozoa, were identified. Deep-water samples were collected in fishing nets at depths ranging between 20 and 200 m along the coasts of the East Sea in Korea from 1976 to 1993. The two species found in this study represent new records for Korea: Paragorgia arborea (Linnaeus, 1758) in the class Anthozoa, and Stylaster profundiporus Broch, 1936 in the class Hydrozoa. Two families, Paragorgiidae and Stylasteridae, are also newly recorded in Korea. Furthermore, the species name of another cold-water gorgonian species, Primnoa pacifica (Kinoshita, 1907) in the family Primnoidae, is amended in this report. The two newly recorded cold-water coral species from Korea are described in detail based on their morphological characteristics. Paragorgia arborea is characterized by its growth form, medulla and cortex, zooid dimorphism, canal system, and spicule composition. Stylaster profundiporus is distinguished by its external skeletal characteristics, such as the coordination of dactylopores and gastropores, presence or absence of gastrostyles and dactylostyles, cyclosystem orientation, ampullar position, gastropore tube shape, and coenosteal texture.

The Evaluation and Countermeasures for the 2nd Arc Reduction for the High Speed Reclosing in 765kV Transmission Line (765kV 계통의 고속도 다상 재폐로 관련 2차 아크 검토 및 억제 방안)

  • Ahn, J.S.;Kim, J.Y.;Jin, J.Y.
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.613-615
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    • 1995
  • KEPCO is now going on upgrading the highest system voltage from 345kV to 765kV since 1992. The main reason of this 765kV project is the bulk power transmission from the power generation sites at the East and West coasts to the Kyeong-in area. The first 765kV transmission lines will be constructed by 1998 and operated as 345kV level until 2001. This system needs a detailed evaluation of the 2nd arc in case of 765kV transmission line outages and the countermeasures for the fast arc reduction for the successful high speed reclosing. So, this paper deals with the simulation results of the 2nd arc characteristics using EMTP and comparison of Sh.R and HSGS for the reduction methods.

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Regional and Seasonal Distribution Properties of Airborne Chlorides in Jeju Island, South Korea (제주도 해안가 대기중 염분량의 지역적/계절적 분포 특성)

  • Jung, Jahe;Lee, Jong-Suk
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.10 no.3
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    • pp.300-306
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    • 2022
  • The distribution properties of airborne chlorides at the coasts of Jeju island were identified in this study. For this, Jeju island was divided into four regions-east, west, south, and north, and the airborne chlorides were investigated in those regions. And the regional and seasonal distribution properties of airborne chlorides were analyzed. Jeju island, which has a subtropical climate and is surrounded by ocean, has a great regional variation in the distribution properties of airborne chlorides, with a difference of more than 6 times between the eastern region, the highest region, and the southern region, the lowest region. In terms of seasonal properties, the airborne chlorides in eastern and western region were high in summer and fall, and in summer mainly due to typhoon. The airborne chlorides in northern region were high in winter due to the northwest wind, and the that of southern region were high in summer. Meanwhile, the airborne chlorides of Jeju island tends to be high compared to the eastern, western, and southern coasts of South Korea.

Evaluation of Shoreline Retreat Rate due to a Sea Level Rise using Theory of Equilibrium Beach Profile (평형해빈단면이론을 이용한 해수면 상승에 따른 해안후퇴율 산정)

  • Kang, Tae Soon;Cho, Kwangwoo;Lee, Jong Sup;Park, Won Kyung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.4
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    • pp.197-206
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    • 2014
  • The purpose of this study is to evaluate coastal erosion due to a sea-level rise. The shoreline retreat rate was calculated due to future sea-level rise. Shoreline retreat rates were quantified with the cross-sectional data of 23 sandy coasts (12 sites from east coast, 5 sites from south coast, and 6 sites of west coast) and 3 cross-sectional profiles from each side of the coasts in Korea. The theory of equilibrium beach profile was employed in this study to evaluate the applicability of the theory into the coast of Korea and was tested with 15 cross-sectional beach profiles. Four scenarios of future sea level rise such as 38 cm, 59 cm, 75 cm, and 100 cm were adopted to estimate the shoreline retreat rates. Overall shoreline retreat rates for the coasts in Korea were predicted as 43.7% for 38 cm, 60.3% for 59 cm, 69.2% for 75 cm, and 80.1% for 100 cm sea level rises, respectively. Retreat rates in the east coast (29.6% for 38 cm, 45.1% for 59 cm, 56.0% for 75 cm, and 69.9% for 100 cm) showed relatively low compared to the south coast (51.9%, 67.6%, 77.2%, 87.3%) and the west coast (53.8%, 71.0%, 78.5%, 86.4%). However, all sandy coasts in Korea were assessed to be vulnerable with increasing sea-level rise. There are uncertainties in the assessment of this study, which include the limitation of the assessment model and the lack of the spatio-temporal data of the beach profiles. Therefore, this study shows that it is very important to spend integrated efforts to respond coastal erosion including comprehensive observations(monitoring) and the development of scientific understanding on the field.

Estimation of Tsunami Risk Zoning on the Coasts Adjacent to the East Sea from Hypothetical Earthquakes (공백역 지진에 의한 동해에 연한 해안에서의 지진해일 위험도 산정)

  • 최병호;에핌페리놉스키;이제신;우승범
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.5
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    • pp.1-17
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    • 2002
  • Prognostic characteristics of hypothetical tsunamis in the East Sea are further discussed based on numerical simulations using linear long wave theory than the last paper(Choi et al). As for choice of source zones, we used 28 cases based on fault parameters of hypothetical earthquakes and 76 cases based on simple initial surface shapes of tsunamigenic earthquakes selected by the seismic gap theory. As a result, the wave heights along the whole coastline adjacent to the East See of tsunamis due to these hypothetical earthquake are presented. Analyses also lead us to conclude that the selection of geographical zones with low risk of tsunamis can be used as a tool for coastal disaster mitigation planning.

The Intensification of Walker Circulation over the Past 15 Years from 1999 and Its Relation to TC Activity in the Western North Pacific

  • Choi, Jae-Won;Cha, Yumi;Kim, Jeoung-Yun
    • Journal of the Korean earth science society
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    • v.37 no.6
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    • pp.359-372
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    • 2016
  • The time-series of Walker circulation index (WCI) in this study shows the strengthening of the Walker circulation in recent years. To further understand the large-scale features related to the WCI strengthening, a difference between the averaged meteorological variables in two time periods 1999-2013 and 1984-1998 is analyzed. The difference in 850 hPa stream flows between the two periods shows that the anomalous easterlies (anomalous trade wind) are dominant due to the strengthening of anomalous anticyclonic circulations at the subtropical Pacific of both hemispheres. The difference between the averaged zonal atmospheric circulations over $5^oS-5^oN$ in the two periods confirms that upward flows are strengthened at the tropical western Pacific and downward flows are strengthened at the tropical central and eastern Pacific in recent years. It matches the WCI strengthening in recent years. The time-series of tropical cyclone (TC) genesis frequency from July to September shows that a mean TC genesis frequency from 1999-2013 decreases compared to that of the time period 1984-1998. The monsoon trough in the period 1984-1998 was located in the further east direction and stronger than that in the period 1999-2013. TCs in the recent period that are generated in further west than TCs in the past period moved from the west. Thus, the TC intensity along the coasts in East Asia becomes weaker in recent period. The intensification of Walker circulation in recent years is related to the weaker TC intensity in East Asia through strengthened anomalous anticyclones at the subtropical western Pacific.

Effect of Summer Sea Level Rise on Storm Surge Analysis (하계 해수면 상승이 폭풍해일고 분석에 미치는 영향)

  • Kim, A Jeong;Lee, Myeong Hee;Suh, Seung Won
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.6
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    • pp.298-307
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    • 2021
  • Typhoons occur intensively between July and October, and the sea level is the highest during this time. In particular, the mean sea level in summer in Korea is higher than the annual mean sea level about 14.5cm in the west coast, 9.0 to 14.5cm in the south coast, and about 9.0 cm in the east coast. When the rising the sea level and a large typhoon overlap in summer, it can cause surges and flooding in low-lying coastal areas. Therefore, accurate calculation of the surge height is essential when designing coastal structures and assessing stability in order to reduce coastal hazards on the lowlands. In this study, the typhoon surge heights considering the summer mean sea level rise (SH_m) was calculated, and the validity of the analysis of abnormal phenomena was reviewed by comparing it with the existing surge height considering the annual mean sea level (SH_a). As a result of the re-analyzed study of typhoon surge heights for BOLAVEN (SANBA), which influenced in August and September during the summer sea level rise periods, yielded the differences of surge heights (cm) between SH_a and SH_m 7.8~24.5 (23.6~34.5) for the directly affected zone of south-west (south-east) coasts, while for the indirect southeast (south-west) coasts showed -1.0~0.0 (8.3~12.2), respectively. Whilst the differences between SH_a and SH_m of typhoons CHABA (KONG-REY) occurred in October showed remarkably lessened values as 5.2~ 14.2 (19.8~21.6) for the directly affected south-east coasts and 3.2~6.3 (-3.2~3.7) for the indirectly influenced west coast, respectively. The results show the SH_a does not take into account the increased summer mean sea level, so it is evaluated that it is overestimated compared to the surge height that occurs during an actual typhoon. Therefore, it is judged that it is necessary to re-discuss the feasibility of the surge height standard design based on the existing annual mean sea level, along with the accurate establishment of the concept of surge height.

Isotopic Determination of Food Sources of Benthic Invertebrates in Two Different Macroalgal Habitats in the Korean Coasts (동위원소 분석에 의한 동해와 남해 연안의 상이한 해조류 군락에 서식하는 저서무척추동물 먹이원 평가)

  • Kang, Chang-Keun;Choy, Eun-Jung;Song, Haeng-Seop;Park, Hyun-Je;Soe, In-Soo;Jo, Q-Tae;Lee, Kun-Seop
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.4
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    • pp.380-389
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    • 2007
  • Stable carbon and nitrogen isotopes were analyzed in suspended particulate organic matter, macroalgae and macrobenthic invertebrates in order to determine the importance of primary organic matter sources in supporting food webs of rocky subtidal and intertidal macroalgal beds in the Korean coasts. Investigations were conducted at the inter tidal sites within Gwangyang bay, a semi-enclosed and eutrophicated bay, and the subtidal sites of the east coast, a relatively oligotrophic and open environment, in May and June 2005. Water-column suspension feeders showed more negative $\delta^{13}C$ values than those of the other feeding guilds, indicating trophic linkage with phytoplankton and thereby association with pelagic food chains. In contrast, animals of the other feeding guilds, including interface suspension feeders, herbivores, deposit feeders, omnivores and predators, displayed relatively less negative $\delta^{13}C$ values than those of the water-column suspension feeders and similar with that of macroalgae, indicating exclusive use of macroalgae-derived organic matter and association with benthic food chains. Most the macrobenthic species were considered to form strong trophic links with benthic food chains. In addition, the distribution of higher $\delta^{15}N$ values in macrobenthic consumers and macroalgae at the intertidal sites of Gwangyang Bay than those at the subtidal sites of the east coast suggests that anthropogenic nutrients may enhance the macroalgal production at the intertidal sites and in turn be incorporated into the particular littoral food web in Gwangyag Bay. These results confirm the dominant role of macroalgae in supporting rocky subtidal and intertidal food webs in the Korean coasts.

The Mask-Dance Performances in the Shaman Rituals: and (굿 속의 탈놀이:<영산 할아?.할?굿>과 <탈굿>)

  • Lee, Meewon
    • Journal of Korean Theatre Studies Association
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    • no.40
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    • pp.5-27
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    • 2010
  • The Korean Mask-Dance Theatre has been developed closely related to Korean Shaman rituals. As many scholars noticed, the performers of the Mask-Dance Theatre were closely related to the Shaman family. In addition, there are mask-dance performances in actual shaman rituals. and are the representative performances among them. This essay intends to compare these two mask-dance performances in the shaman rituals to the similar performance of Old Grandpa and Grandma episode in the regional Mask-Dance Theatre. This study would bring us further in proving the close relation between the shaman ritual and the Mask-Dance Theatre. is one episode, Keori, in the shaman ritual of 'Baeyeonsin-kut' and 'Taedong-kut' in the mid-west seashore area. 'Taedong-kut' is the village shaman ritual for fertility and prosperity, while 'Baeyeonsin-kut' is a private shaman ritual for a large catch of the ship. is held in the later part of the whole shaman ritual since the later part tend to be more for entertainment than actual ritual. The story of is very similar that of in Pongsan Mask-Dance Theatre of the mid-west region. In addition, some of their dialogues are very similar. Only the later part is different. These similarities indicate that the Mask-Dance Theatre, which came into being in later period than the shaman ritual, has likely taken the story motif of the shaman ritual. is also a performance in the shaman ritual of east coasts. is more elaborate and recreational than of the west coasts. is also performed near the end of the ritual, and sometimes it is not performed at all. This indicates that has little ritual meaning left. When we compare it with the regional Mask-Dance Theatres such as Keosung Okwangdae, Tongyong Okwangdae, and Suyong Yaryu, the structure and the story lines are also very similar. It is a question why only the motif of the Grandpa and Grandma isfound both in the shaman ritual and the Mask-Dance Theatre. Many other motifs of other episodes in the Mask-Dance Theatre are not found in the shaman rituals. It seems that the Grandpa and Grandma motif is related to the ur-belief in fertility. In other words, this motif seems to be originated from the old belief in the fertility couple of Chonha Taechanggun and Jiha Yeochanggun. The shaman ritual for fertility first picked up this motif, and then the mask-dance theatre also adapted this motif for its recreational purpose. When we compare with , still has more aspects of fertility ritual, while lost its ritualistic meaning and its main purpose is to develop dramatic needs. and are invaluable existent performances to prove theatre's origin in ritual. The existence of mask-dance performances in the shaman rituals shows us the transit performance between theatre and ritual.