• Title/Summary/Keyword: Jeju-Island

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Characterization of Hydroxy-interlayered Mineral in Non-Andic Soils from Jeju Island

  • Lee, Gyoo-Ho;Yungoo Song;Ha, Dae-Ho;Moon, Hi-Soo;Moon, Ji-Won
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2001.06a
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    • pp.45-47
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    • 2001
  • Jeju island is composed mainly of volcanic rocks such as basalts, trachytic andesites, tracytes, and sedimentary rocks. About 80% of Jeju soils are classified as Andisols. The amount of annual precipitation in Jeju island is about 1872mm, which is 1.5 times the annual precipitation of south Korea. There is a significant difference In amount of precipitation with regions even within Jeju island. In study area, the annual amount of rainfall is about 1280mm, the lowest in Jeju island while south part of the island has the annual precipitation of 2056mm, though they are only tens of kilometers apart. The parent materials of soils in study area are pyroclastic rocks and tuffs. The soils of non-andic properties have developed in this area since pedogenic process of pyroclastic materials is strongly influenced by climatic factor, especially precipitation. In order to investigate the mineralogical characteristics of soils, X-ray analysis for <0.2 and 2-0.2$\mu\textrm{m}$ size fractions was performed with ethylene glycol solvation, K-, Mg-saturation, heat treatment(110, 330, 550$^{\circ}C$). Acid-oxalate and DCB(sodium hydrosulfite, sodium citrate, sodium bicarbonate) dissolution method was used to assess tile total amounts or Al, si, and hydroxy interlayer or 2:1 layer silicates. XRD was also applied for samples treated with DCB only and DCB-oxalate sequentially. XRD patterns showed that 2:1 and 1:1 layer silicates were found, which are different from soils of Andisols. Vermiculite, chlorite, hydroxy interlayered minreals, and interstratified minerals(vermiculite/chlorite) were observed in 2-0.2$\mu\textrm{m}$ size fractions. After DCB treatments, ethylene glycolated samples with Mg-saturation showed expanded d-spacing, suggesting the possibility of hydroxy interlayered minerals. The amounts of hydroxy interlayered minerals increased in surface soil. Unlike Andisols, short range ordered minerals such as allophane, imogolite and gibbsite were hardly found. Mica and kaolinte existed in small amounts. Results are summarized in Fig 1 and Fig. 2.

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Numerical Studies on the Variation of Flow Structure Due to Sea Surface Temperature at the Lee Side of Jeju Island in the Korean Peninsula (해수면 온도변화에 따른 제주도 후면 흐름구조 변화에 관한 수치연구)

  • Lee, Soon-Hwan;Park, Gwang-Soon
    • Journal of the Korean earth science society
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    • v.27 no.1
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    • pp.61-72
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    • 2006
  • Numerical studies on the influence of interaction between atmosphere and ocean on the variation of Karman vortex at the lee side of Jeju Island were carried out. Karman vortex tends to be occurred at limited height associated with Hanla mountain. And we can find clear Karman vortex at 900 hPa height in this study. One big vortex cell occurred at lee side of Jeju Island in the begging stage of its development and the cell was divided into three small cells as time goes by. And the strength and lifetime of small vortexes depend on the distribution of SST (Sea Surface Temperature). Weak gradient of SST makes long-lasting Karman vortex but produces weak potential vorticity at lee side of Jeju-do in comparison with the vortex under strong SST gradient. Strong SST gradient also increases not only the mixing depth but also the mixing ratio at lower level of troposphere. And the increased atmospheric mixing decreases the mechanical forcing due to isolated topography. Then the strength of Karman vortex at the lee side of Jeju Island becomes weak under strong gradient of SST. Thus the evolution of Karman vortex is closely related to distribution of SST around the isolated island.

Habitat Quality Valuation Using InVEST Model in Jeju Island (InVEST 모델을 이용한 서식처 가치 평가 - 제주도를 중심으로 -)

  • Kim, Teayeon;Song, Cholho;Lee, Woo-Kyun;Kim, Moonil;Lim, Chul-Hee;Jeon, Seong Woo;Kim, Joonsoon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.5
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    • pp.1-11
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    • 2015
  • Jeju Island is managed intensively in terms of environmental and ecological aspect because of its extraordinary ecosystem types comprising numerous rare, protected flora and fauna. To depict rapid change of habitat status in Jeju Island, the InVEST Habitat Quality model has been operated and compared analytically with the Eco-Natural map. The Habitat Quality map of Jeju Island is turned out to have similar inclination with Eco-Natural map. We compared the average habitat quality value in each Eco-natural map class in Jeju Island and the habitat quality value of first second third grade and non-included area decreased as 0.95 0.76, 0.53 and 0.37 in eco natural map respectively. Compared to biodiversity map based on biological investigation, the result of the InVEST habitat quality model can be simply obtained by land cover map with threat and sensitivity data. Further studies are needed to make explicit coefficients for Jeju Island and Korean peninsula, then the Habitat Quality model could be applied to past and future scenarios to analyze extent of habitat degradation in time series to help decision makers.

Distribution and morphological development of a Gnathophis nystromi (Congridae: Anguilliformes) leptocephalus collected from southeastern waters of Jeju Island (제주도 남동부해역에서 채집된 은붕장어, Gnathophis nystromi (뱀장어목: 붕장어과) 엽상자어의 분포특성 및 형태발달)

  • JI, Hwan-Sung;CHOI, Jung Hwa;YOON, Sang Chul;JOO, Hyeong Woon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.4
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    • pp.527-534
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    • 2015
  • The twenty six specimens of leptocephali (15.8-32.6 mm TL) of the family Congridae, collected from southeastern waters offshore of Jeju Island during August 2014, and were identified by means of morphology and genetics. Those specimens were identified as belonging to the family Congridae based on various combinations of morphological characters. An analysis of the partial 12S rRNA sequences (886 base pairs) of mitochondrial DNA showed that our specimens must be Gnathophis nystromi, because their sequences were concordant with those of G. nystromi adult (genetic distance= 0.001), furthermore their total myomeres being consistent with those of G. nystromi adult. Catch rates of G. nystromi leptocephali were higher in the offshore regions than coastal regions of Jeju Island. The smallest leptocephali (< 20 mm TL) were collected offshore from Jeju Island. We hypothesize that one of the spawning grounds of G. nystromi is located offshore in the Jeju Island. In conclusion, the hatched preleptocephali of G. nystromi might have been transported from offshore near Jeju Island to the Korea Strait by the Kuroshio Current and Tsushima Warm Current.

Acharacteristics on the forming of fishing ground and population ecological study of Yellow tail, Seriola quinqueradiata, in the coastal waters off Gim-nyeong of Jeju Island, Korea (제주도 김녕 연안해역의 방어 어장형성 특성과 자원생물학적 기초 연구)

  • Chang, Dae-Soo;Yoo, Joon-Taek;Kim, Byung-Yeob;Lee, Seung-Jong;Kwon, Dae-Hyeon;Koo, Jun-Ho;Ahn, Gem-Ma;Oh, Im-Yeol
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.4
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    • pp.406-415
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    • 2010
  • The forming of fishing ground and the population ecological characteristics of yellowtail, Seriola quinqueradiata, in the coastal waters off Gim-nyeong of Jeju Island were investigated. The stock of yellowtail, Seriola quinqueradiata, between Jeju Island and coastal areas of the East Sea is probably the same. Water temperature probably is a major factor for controlling distribution of yellowtails in deeper, offshore areas off Jeju Island. However, the major factor that determines aggregation of yellowtails in coastal areas of Jeju Island, especially off Gim-nyeong is probably strong tidal currents driven by distribution of yellowtails rather than hydrological conditions such as Yellowtails collected off Jeju Island were from 1 to 4yrs old and about 50% of them were $1^{-yr}$ old, probably indicating overfishing. Jack mackerel was the major prey item for yellowtails off Gim-nyeong from October to March, suggesting concurrence of the two species.

Assessment of DMS photochemistry at Jeju Island During the Asian Oust-Storm Period of Spring 2001 : Comparison of Model Simulations with Field Observations

  • Shon, Zang-Ho;Hilton Swan;Keith N. Bower;Kim, Ki-Hyun;Lee, Gangwoong;Kim, Jiyoung
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.11a
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    • pp.343-343
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    • 2002
  • This study examines the influence of long-range transport of dust particles and air pollutants on both local/regional DMS oxidation chemistry and the distribution of sulfur compounds at Jeju Island (33.17$^{\circ}$ N. 126.10$^{\circ}$ E) during the Asian dust-storm(ADS) period in April 2001. The atmospheric concentrations of these sulfur species were measured at a ground station on Jeju Island. Korea as Part of the ACE-Asia intensive operation. Three ADS events were observed during the periods of 10-12, 13-14. and 25-26 April. respectively. The concentrations of DMS and CS$_2$ were higher during the ADS period than during the non-Asian-dust-storm (NADS) period. Conversely. a difference in SO$_2$ levels during the ADS period was not distinguishable from those during the NADS period. The diurnal variation pattern of DMS observed was largely different from that in the remote marine boundary layer. DMS loss by NO$_3$ in the atmospheric boundary layer was dominant due to significantly high NOx levels influenced by the long-range transport of pollutants from East Asia to Jeju Island The DMS maximum during the ADS period was observed in the late afternoon. The oceanic fluxes of DMS during the ADS and NADS periods were estimated to be 5.7$\pm$2.3 and 2.9 (+2.8/-1.5) mole m$^{-2}$ day$^{-1}$ . respectively. The contribution of oxidized DMS to SO$_2$ levels at Jeju Island during the study period was found to be insignificant.

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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.

Estimating Willingness-to-pay for the Ground Water Quality Improvement in Jeju Island Using Contingent Valuation Method (조건부가치측정법을 이용한 제주도 지하수 수질개선에 대한 지불의사액 추정)

  • Jungkyu Park;Chanhee Lee
    • Environmental and Resource Economics Review
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    • v.31 no.4
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    • pp.619-644
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    • 2022
  • The purpose of this study is to estimate the economic benefit of improving ground water quality in Jeju Island, where groundwater pollution has recently become a social issue and various water quality improvement projects are being promoted. By applying the contingent valuation method, an online survey was conducted on Jeju Island residents to analyze the response data of 542 respondents and estimate the mean willingness to pay using 16 models. The estimation of the double-bounded dichotomous choice model confirmed that each household was willing to pay 28,008 won per year, with the willingness to pay estimated at a minimum of 17,762 won and a maximum of 37,416 won based on different models. The total annual benefit for Jeju Island's ground water quality improvement was estimated to be about 8.66 billion won , and socioeconomic factors influencing willingness-to-pay were investigated. This study is expected to serve as a foundation for the development of environmental improvement policies by assisting in the understanding of Jeju Island's unique water resource environment.

Selection Attributes on Behaviour Intention of Island Tourism : focused on Chuja region (도서 관광지의 선택속성, 서비스 가치, 만족도 및 행동의도 관계 연구: 추자도를 대상으로)

  • Choi, Yong-Bok;Boo, Chang-San;Kim, Min-Cheol
    • Journal of Fisheries and Marine Sciences Education
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    • v.24 no.3
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    • pp.406-415
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    • 2012
  • The objective of this paper was to analyze the relationships between the factors of selection attributes and the behavior intention focusing on Domestic tourists in Chuja island. This paper utilized the path analysis to investigate the factors of selection attributes affecting the visitors' satisfaction and re-visit intention through service value as mediating factor. This study showed the most important thing among the factors influencing service value in research model was 'uniqueness of island'. Finally, this paper presented that the selection attributes had affected overall satisfaction and re-visit intention through the mediation of service value. In addition, this study calculated total effect including indirect and direct effect of the choice attributes on behavior intention. This result can give the stakeholders related to Chujado island a implication for a better policy of tourism development.

Characteristics of External and Cranial Morphological Characters of Asian Lesser White-Toothed Shrew (Crocidura shantungensis) (작은땃쥐 (Crocidura shantungensis)의 외부 형태 및 두개골 형질의 특성)

  • Kim, Tae-Wook;Park, Su-Gon;Kim, Yoo-Kyung;Park, Jun-Ho;Adhikari, Pradeep;Kim, Ga-Ram;Park, Seon-Mi;Lee, Jun-Won;Han, Sang-Hyun;Oh, Hong-Shik
    • Korean Journal of Environmental Biology
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    • v.33 no.4
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    • pp.441-449
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    • 2015
  • This study was conducted to screen the characteristics of external and cranial characters of Crocidura shantungensis collected from Korean Peninsula, Ulleung Island and Jeju Island. There were significant differences in head-body length (HBL), tail length (TL), ear length (EL), and hind foot length (HFL) in males and HBL, TL, and HFL in females among three populations (p<0.05). The HBL and TL in the Jeju Island population were larger (8.0 mm and 4.0 mm in lengths, respectively) than those of the Korean Peninsula population. Based on skull analysis, a total of thirteen traits showed significant differences among the three populations (p<0.05). The condylo-insicive length (CIL), maximum width of brain case (MWB), mandibular length (ML), and mandibular height (MH) in the Jeju Island population were significantly larger than those of Korean Peninsula population (p<0.05). Principle component analysis (PCA) showed that two principle components (PC) identified from the PCA affected on the body size and width of the skull, respectively. Discriminant analysis revealed that these populations could be discriminated through skull traits. These findings concluded that the Jeju Island population was greater in the size than the Korean Peninsula, suggesting that the Jeju Island shrews have successfully adapted to the island environments and they had morphologically differentiated during glacial period after natural immigration into that Island. Thus, this study supports the 'Island Rule', showing that the population is well adapted to the island environments. This may provide important information for biogeographical and ecological studies on insular animals.