• Title/Summary/Keyword: southwestern coast

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Heavy Metal Concentrations of Marine Surface Sediments and Benthic Foraminifera in Southern and Southwestern Coastal Areas of Korea (국내 남해 및 남서해안지역 해양퇴적물과 저서성 유공충 골격내 중금속함량)

  • Kim, Kyoung-Woong;Yun, Hye Su;Yi, Song Suk;Jung, Kyu-Kui
    • Economic and Environmental Geology
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    • v.30 no.3
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    • pp.223-230
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    • 1997
  • The skeletal chemistry of calcareous microfossils may contribute to the classification of various biological processes and be used as an environmental indicator for future pollution. In order to examine the degree of heavy metal pollutions in marine environments, samples of sediment and benthonic foraminifera were taken from 5 study areas from 3 different stations in coastal offshore regions of Korea. After sieving, cleaning and acid digestion, sample were analyzed for heavy metals by ICP-MS, ICP-AES and AAS. Concentrations of Cd, Cu, Pb and Zn in most of marine sediments from 5 study areas are not higher than those in sediments from unpolluted marine environment in the U.K.. However, pollution indices are up to 0.96~0.99 in the Gwangyang and Yulchon areas which are classified as the special control distric along the coast for pollution. The pollution indices decrease in order of Yulchon > Gwangyang > Mokpo > Gamak = Yoja > Yonggwang areas. Concentrations of Mg, Pb, Sr and Zn in Ammonia beccarii Pseudorotalia gaimardii, Quinqueloculina lamarckiana are reduced after pre-treatment of samples. From the result of bioconcentration index, Mg is easily accumulated in microfossils and Quinqueloculina lamarckiana may be used as the best indicator for future pollution.

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Diversity and Faunal Changes of the Macrolepidoptera in Mt. Duryunsan and Its Neighboring Area, Jeonnam, Korea (전남 두륜산 일대에 서식하는 대형나방종의 다양성 및 종 구성 변화)

  • Choi, Sei-Woong;Na, Sang-Duck
    • The Korean Journal of Ecology
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    • v.28 no.2
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    • pp.79-83
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    • 2005
  • We investigated the species richness of macrolepidoptera (including pyralid moths) in the evergreen broad-leaved forests of southwestern coast of Korea. The studied site was Mt. Duryunsan and its neighboring area, Haenam-gun, Jollanam-do and moths were identified and analyzed after collecting them with UV light traps from 2001 to 2004. A total number of species comprised 18 families and 489 species. We expected that the number of species would be increased when the species of microlepidoptera and butterflies were included. The family Noctuidae with 181 species was dominant in the area followed by Geometridae with 129 species and Pyralidae with 72 species. Based on number of collected individuals, Geometridae was the highest and followed by Noctuidae, Pyralidae and Drepanidae. Fifty-one percent of the total species consisted of less than two specimens in the collected sample. Monthly changes of numbers of species and individuals were examined and indices of Simpson's heterogeneity and evenness were also drawn. We briefly discussed the possibility of moth species or group of species as bioindicator for assessing the condition of forest after disturbance.

Characteristics of Snowfall Event with Radar Analyses over Honam District and Gwangju Occurred by Cloud Streets over Yellow Sea for 04 Jan. 2003 (서해상에 발생하는 Cloud Streets에 동반된 2003년 1월 4일 강설의 레이더관측사례 분석)

  • Shin, Ki-Chang;Ryu, Chan-Su
    • Journal of Environmental Science International
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    • v.19 no.10
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    • pp.1187-1201
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    • 2010
  • The formation and development conditions of the cloud streets over the yellow sea by the Cold Surge of Siberian Anticyclone Expansion which produce the heavy snowfall events over the southwestern coast, Honam District of the Korean peninsula, has been investigated through analyses of the three dimensional snow cloud structures by using the CAPPI, RHI, VAD and VVP data of X-band Radar at Muan Weather Observatory and S-band Radar at Jindo Weather Station. The data to be used are obtained from January 04, 2003, when heavy snow storm hits on Gwangju and Honam District. The PPI Radar images show that the cloud bands distribute in perpendicular to the expansion direction of the high pressure and that the radius of cloud cells is about 5~8 km with 20~30 dBz and distance between each cell is about 10 km. And but the vertical Radar images show that the cloud street is a small scale convective type cloud within height of about 3 km where a stable layer exists. From the VVP images, the time period of the high pressure expansion, the moving direction and development stages of the system are delineated. Finally, the vertical distribution of wind direction is fairly constants, while the wind speed sheer increases with altitude to 3 km.

Water quality in Mokpo coastal area after a strong rainfall (집중 강우시 목포 주변해역의 수질 특성)

  • Kim Do-Hee;Ryu Han-Hong
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.6 no.2
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    • pp.28-37
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    • 2003
  • We investigated water quality, salinity, nutrients, SS, COD and Chlorophyll-a concentrations in the seawater of the Mokpo costal area, southwestern coast of Korea. Seawater samples at 25 stations were collected in July 20, 25 and September 3, 2002 after a strong rain event. The distributions nutrients in seawater were analyzed using an method of sea water analysis presented by the ministry of Maritime Affairs and Fisheries of Korea. The sampling sites were categorized into the inner and outer harbour based on salinity distribution and difference of nutrients distributions was evidence between these two zones. Nutrients and SS inflow and distributed in the inner harbour by the discharged freshwater from Youngsan river during strong rainfall whereas they were distributed in seawater of outer harbour by natural processes in general coastal area.

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Mosquito Species Composition and Plasmodium vivax Infection Rates on Baengnyeong-do (Island), Republic of Korea

  • Foley, Desmond H.;Klein, Terry A.;Lee, In-Yong;Kim, Myung-Soon;Wilkerson, Richard C.;Harrison, Genelle;Rueda, Leopoldo M.;Kim, Heung-Chul
    • Parasites, Hosts and Diseases
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    • v.49 no.3
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    • pp.313-316
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    • 2011
  • Vivax malaria is a significant military and civilian health threat in the north of the Republic of Korea (ROK). The island of Baengnyeong-do is the westernmost point of the ROK and is located close to the southwestern coast of the Democratic People's Republic of Korea (DPRK). Mosquitoes were collected using a black light trap on Baengnyeong-do, and Anopheles spp. were assayed by PCR, to identify the species, and screened for sporozoites of Plasmodium vivax. Of a subsample of 257 mosquitoes, Anopheles lesteri was the most frequently collected (49.8%), followed by Anopheles sinensis (22.6%), Anopheles pullus (18.7%), Anopheles kleini (7.8%), and Anopheles belenrae (1.2%). The overall sporozoite rate was 3.1%, with the highest rates observed in An. kleini (15.0%), An. sinensis (5.2%), and An. lesteri (1.6%). No sporozoite positive An. pullus or An. belenrae were observed. The results extend our knowledge of the distribution and potential role in malaria transmission of An. kleini, An. lesteri, and An. sinensis, for an area previously considered to be at a low risk for contracting vivax malaria.

On the primary productivity in the southern sea of korea (한국남해역(韓國南海域)의 일차생산력(一次生産力))

  • CHUNG, CHANG-SOO;YANG, DONG-BEOM
    • 한국해양학회지
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    • v.26 no.3
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    • pp.242-254
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    • 1991
  • Southern sea of Korea was investigated for primary productivity during four scientific cruises of Korea Ocean research and Development Institute. Frontal structure appeared to be an important physical characteristic in enhancing the phytoplankton production in the study area. Relatively high productivity was occurred near the front between Tsushima Warm Current Water and Coastal Waters of China continent in March 1990 and in November 1989, and near the front between Tsushima Warm Current Water and Korean coastal Water in April 1989. In August 1988 high productive zone was limited to the tidal front off the southwestern coast of Korea. Nutrient supply related to the frontal structure might play a dominant role in increasing the primary productivity but mechanisms of nutrient enrichment are not clear. Average column productivity showed its maximum in April 1989 (1727 mgC/m$^2$/day). In the costal Waters of the china Continent incident light may be an important factor in regulating the regulating the phytoplankton production because of low light penetration rate resulting from high turbidity.

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Using Tower Flux Data to Assess the Impact of Land Use and Land Cover Change on Carbon Exchange in Heterogeneous Haenam Cropland (비균질한 해남 농경지의 탄소교환에 미치는 토지사용 및 피복변화의 영향에 대한 미기상학 자료의 활용에 관하여)

  • Indrawati, Yohana Maria;Kang, Minseok;Kim, Joon
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2013.11a
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    • pp.30-31
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    • 2013
  • Land use and land cover change (LULCC) due to human activities directly affects natural systems and contributes to changes in carbon exchange and climate through a range of feedbacks. How land use and land cover changes affect carbon exchanges can be assessed using multiyear measurement data from micrometeorological flux towers. The objective of the research is to assess the impact of land use and land cover change on carbon exchange in a heterogeneous cropland area. The heterogeneous cropland area in Haenam, South Korea is also subjected to a land conversion due to rural development. Therefore, the impact of the change in land utilization in this area on carbon exchange should be assessed to monitor the cycle of energy, water, and carbon dioxide between this key agricultural ecosystem and the atmosphere. We are currently conducting the research based on 10 years flux measurement data from Haenam Koflux site and examining the LULCC patterns in the same temporal scale to evaluate whether the LULCC in the surrounding site and the resulting heterogeneity (or diversity) have a significant impact on carbon exchange. Haenam cropland is located near the southwestern coast of the Korean Peninsula with land cover types consisting of scattered rice paddies and various croplands (seasonally cultivated crops). The LULCC will be identified and quantified using remote sensing satellite data and then analyzing the relationships between LULCC and flux footprint of $CO_2$ from tower flux measurement. We plan to calculate annual flux footprint climatology map from 2003 to 2012 from the 10 years flux observation database. Eventually, these results will be used to quantify how the system's effective performance and reserve capacity contribute to moving the system towards more sustainable configuration. Broader significance of this research is to understand the co-evolution of the Haenam agricultural ecosystem and its societal counterpart which are assumed to be self-organizing hierarchical open systems.

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Effect of Disturbance on the Compressibility Characteristics of Marine Clay (해성점토의 교란이 압축특성에 미치는 영향)

  • Yu, Sung-Jin;Chae, Young-Su;Kim, Jong-Kook;Yoon, Won-Sub
    • Journal of the Korean Geotechnical Society
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    • v.23 no.12
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    • pp.95-107
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    • 2007
  • This study describes compressive characteristics of marine clay at southwestern coast in Korea by large block and piston samples. Through the analysis of disturbance effect and various consolidation test, consolidation result shows that volumetric strain from large block samples is lower than piston samples and compression index of large block samples is larger than piston samples value. We suggest new empirical equation of compression index by the effect of compression index following sampling method. If consolidation settlement is presumed using empirical equation of compression index, the resort will be more reasonable in predicting settlement than that obtained by the decision of compressibility characteristics from piston samples.

Relationship between Environmental Characteristics and Pigment Composition and Concentrations of Porphyra yezoensis Ueda in the Southwestern Coast of the Korean Peninsula (남서해역에서 양식되는 방사무늬김(Porphyra yezoensis Ueda)의 색소조성과 농도에 영향을 미치는 해양환경 특성)

  • Kim, Jeong Bae;Lee, Won-Chan;Hong, Sokjin;Shim, Jeong Hee;Park, Jung-Im;Park, Jihye;Lee, Eu Gene
    • Korean Journal of Environmental Biology
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    • v.30 no.3
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    • pp.200-209
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    • 2012
  • The effect of water temperature, salinity and water column nutrient contents on pigment composition and concentration of purple lavers were studied at the main purple lavers production areas in Southwestern coast of Korea, during January to March, 2011. Water temperature was between 3.0 and $11.3^{\circ}C$. Salinity range was between 32.7 and 34.7, those were lower St. 1 and St. 6, which were at close to the seashore. Water column dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) and silicate concentrations were $1.73{\sim}12.84{\mu}M$, $0.07{\sim}0.67{\mu}M$ and $4.93{\sim}18.29{\mu}M$, respectively. Chl a concentration was between 0.41 and $9.14{\mu}g\;L^{-1}$, and it was the highest at St. 1 during January. Photosynthetic pigment of fucoxanthin was dominant at all sites, which showed its highest concentration ($0.06{\sim}3.41{\mu}g\;L^{-1}$) at St. 1 on January. Water column DIN concentration was higher at January during low salinity period at all sites, but it was low at St. 1. Photosynthetic pigment of Chl a, PE and PC concentration of porphyra blades was between $1,173{\sim}8,124{\mu}g\;DW\;g^{-1}$, $3,281{\sim}10,076{\mu}g\;DW\;g^{-1}$, $388{\sim}1,346{\mu}g\;DW\;g^{-1}$, respectively. The concentration was relatively high at the St. 2 and St. 3. The pigment concentration of porphyra blades was higher at only Porphyra yezoensis was cultured than at Porphyra yezoensis and Porphyra seriata were cultured. The pigment concentration of porphyra blades was higher at St. 2 and St. 3 in only Porphyra yezoensis was cultured. This study shows that pigment concentration of porphyra blades may depend on habitat environment and culture methods.

Studies on the Distribution and Fluctuation of the Purse-Seine Fishing Grounds in Relation to Oceanographic Conditions in the East China Sea 1 . The Distribution of Mackerels and Jack Mackerel Fishing Grounds (동지나해의 해황과 선망어장의 분포$\cdot$변동에 관한 연구 1. 고등어$\cdot$전갱이 어장의 분포)

  • CHO Kyu-Dae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.14 no.4
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    • pp.239-252
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    • 1981
  • The East China Sea is an important region as nursery and spawning grounds for pelagic fishes such as jack mackerel, common mackerel etc. , and thus constitutes a major fishing area for purse-seine fishery. The environment surrounding in this region is under the influence of the Yellow Sea Cold Water, China Coastal Water and Kuroshio Current. The purpose of this study was to clarify the effects of oceanographic conditions and thermal fronts on the formation of the fishing grounds for the mackerels in the East China Sea. Through the analyses of fisheries statistics during 1968-1976 and temperature data, the following facts are found: 1) Approximately $70\%$ of the total mackerel(common) catches appeared to be come from the Tsushima Current region which includes Sakai coast of the Japan Sea, eastern Tsushima and Shirase Island, and Jeju Island of Korea. This area covers only about $8\%$ of the East China Sea. 2) Main fishing grounds for the jack mackerel are also centered around the area of southwestern Goto, Shirase and eastern Tsushima Island where the catches accounted for about $54\%$ of the total jack mackerel catches. 3) Fluctuations in annual catches are relatively small in the Tsushima Current region, compared to other regions such as Yellow Sea, southwestern coast of Kyushu and mid-western part of the East China Sea, where the fisheries yields varied considerably due to unstable fishing conditions. 4) It appears that the fishing grounds for the jack mackerel are mainly distributed along the warmer region ($15-20^{\circ}C$) of the thermal front, and those for the common mackerel are in somewhat colder region ($13-16^{\circ}C$) in the Tsushima Current.

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