• Title/Summary/Keyword: Small island

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Study on climate change response of small island groundwater resources

  • Babu, Roshina;Park, Namsik
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.182-182
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    • 2017
  • Many small island nations rely on groundwater as their only other source of freshwater in addition to rainwater harvesting. The volume of groundwater resource of small island nations are further limited by their smaller surface area and specific hydrogeology. The rapid growth of population and tourism has led to increasing water demands and pollution of available groundwater resources. The predicted climate change effects pose significant threats to the already vulnerable freshwater lens of small islands in the form of rise in sea level, coastal inundation, saltwater intrusion, varied pattern of precipitation leading to droughts and storm surges. The effects of climate change are further aggravated by manmade stresses like increased pumping. Thus small island water resources are highly threatened under the effects of climate change. But due to the limited technical and financial capacity most of the small island developing states were unable to conduct detailed technical investigations on the effects of climate change on their water resources. In this study, we investigate how well small island countries are preparing for climate change. The current state of freshwater resources, impacts of predicted climate change along with adaptation and management strategies planned and implemented by small island countries are reviewed. Proper assessment and management practices can aid in sustaining the groundwater resources of small islands under climate change.

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Characteristics of tidal current and tidal induced residual current in the channel between Geumo Island and An Island in the southern waters of Korea (금오도-안도 협수로 해역의 조류 및 조석잔차류 특성)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.3
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    • pp.214-227
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    • 2021
  • The distribution of tidal current and tidal induced residual current, topographical eddies and tidal residual circulation in the waters surrounding the Geumo Island-An Island channel were identified through numerical model experiments and vorticity balance analysis. Tidal current flows southwest at flood and northeast at ebb along the channel. The maximum flow velocity was about 100-150 cm/s in neap and spring tide. During the flood current in the neap tide, clockwise small eddies were formed in the waters west of Sobu Island and southwest of Daebu Island, and a more grown eddy was formed in the southern waters of Geumo Island in the spring tide. A small eddy that existed in the western waters of Chosam Island during the ebb in neap tide appeared to be a more grown topographical eddy in the northeastern waters of Chosam Island in spring tide. Tidal ellipses were generally reciprocating and were almost straight in the channel. These topographical eddies are made of vorticity caused by coastal friction when tidal flow passes through the channel. They gradually grow in size as they are transported and accumulated at the end of the channel. When the current becomes stronger, the topographic eddies move, settle, spread to the outer sea and grow as a counterclockwise or clockwise tidal residual circulation depending on the surrounding terrain. In the waters surrounding the channel, there were counterclockwise small tidal residual circulations in the central part of the channel, clockwise from the northeast end of the channel to northwest inner bay of An Island, and clockwise and counterclockwise between Daebu Island and An Island. The circulation flow rate was up to 20-30 cm/s. In the future, it is necessary to conduct an experimental study to understand the growth process of the tidal residual circulation in more detail due to the convergence and divergence of seawater around the channel.

독도의 주권과 해양 경계 획정

  • 박성일
    • Proceedings of KOSOMES biannual meeting
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    • 2005.05a
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    • pp.53-61
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    • 2005
  • Dokdo, a group of 33 small and rocky Islets, in the East Sea have been administered by Korea for years since 1953 and are currently occupied by Korean Police Unit. Located about 217Km off the eastern border of Korea and 87Km east of UIleung Island in North Gyeongsang Province. Situated in the East Sea of Korea, Dokdo itself has valuable strategic implications for Korea as well as another countries such as Russia, Japan, U.SA etc. The first historical testimonies to Dokdo were in Korean documents referring to it as a part of an independent island district known as Ulleung Island(Usanguk), which was incorporated into Silla Kingdom in 512 A.D. in '1454 Sejong Authentic History'. Historically, since at least 1881, the island has been called Dokdo by Koreans, meaning 'Rock Island' or 'Lonely Island'. Also Korea, which regained a full sovereignty and have exercised it for decades continuously, keeps a small police detachment on the Island. That is, Dokdo is under effective control of Korea until today. Therefore Dokdo, which is a problem that is related to our territory and sovereignty, is clearly a cluster of Islands of Korea.

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A simple Model for Separation of the Tsushima Current Stream Core by the Tsushima Island: a small viscosity limit

  • Seung, Young-Ho
    • Journal of the korean society of oceanography
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    • v.38 no.2
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    • pp.45-51
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    • 2003
  • Recent observations reveal that the Tsushima Current has a double-cored structure downstream of the Tsushima Island. To explain this, a simple analytical model is proposed based on the assumption of small lateral eddy viscosity. This model suggests that an otherwise uniform current becomes to have a stream core immediately after it enters a channel due to the action of lateral friction. The core is initially broad but becomes sharper downstream. The speed at which the core develops depends on the intensity of lateral eddy viscosity. Likewise, a single-cored stream changes rapidly to a double-cored stream when it passes through an island located in the center of the channel. When the stream leaves the island behind, the reverse process from the double-to single-cored structures takes place. In this case, however, the double-cored structure is retained for a significant distance from the island. Overall, this model suggests that the double-cored structure of the Tsushima Current observed downstream of the Tsushima Island Is created by the lateral friction exerted by the Tsushima Island.

Vulnerability assessment of drought of small island areas in Korea (읍면 단위 도서지역의 가뭄 취약성 평가)

  • Shim, Intae;Hong, Bongchang;Kim, Eunju;Hwang, Tae-Mun
    • Journal of Korean Society of Water and Wastewater
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    • v.33 no.5
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    • pp.341-351
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    • 2019
  • The purpose of this study was to evaluate vulnerability of drought in small island areas. Vulnerability assessment factors of drought were selected by applying the factor analysis. Ninety Eup/Myon areas in small island were evaluated to vulnerability of drought by entropy method adapting objective weights. Vulnerability consisted of climate exposure, sensitivity, and adaptive capacity. A total of 22 indicators were used to evaluate and analyze vulnerability of drought in small island areas. The results of entropy method showed that winter rainfall, no rainfall days, agricultural population rate, cultivation area rate, water supply rate and groundwater capacity have a significant impact on drought assessment. The overall assessment of vulnerability indicated that Seodo-myeon Ganghwa-gun, Seolcheon-myeon Namhae-gun and Samsan-myeon Ganghwa-gun were the most vulnerable to drought. Especially Ganghwa-gun should be considered policy priority to establish drought measures in the future, because it has a high vulnerability of drought.

Taxonomic Stautus of Striped Field Mice(Mammalia: Rodenita) from Wando Island, Korea (한국 완도에 서식하고 있는 등줄쥐(포유강: 설치목)의 분류학적 위치)

  • Hung Sun Koh;Bo Yeong Lee;Yong Kim Ki Kim;Sang Kyu Yoo;Byeong Kug Yang
    • Animal Systematics, Evolution and Diversity
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    • v.14 no.1
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    • pp.51-57
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    • 1998
  • Thirty one morphometric characters of striped field mice(Apodemus agrarius) from eight localities in Korea were analyzed by multivariate methods in order to confirm taxonomic status of specimens from Wando island. Two subgroups were recognized: a small-size form from six localities (Mt. Taebaek, Mt. Weolak, Cheongju, Mt. Chiri, Kunsan, and Jin isoland) and a large-size form from Wando island and Cheju island. It is confirmed that the small-size form from six localities is A. a. coreae, as described by Thomas(1908), and that the large-size form from Cheju island is A. a. chejuensis, as named by Johnson and Jones (1955). Furthermore, it is confirmed that large-size specimens from Wando island is and Cheju island. It is confirmed that the small-size form from six localities is A. a coreae, as described by Thomas(1908), and that the large-size form from Cheju island is A. a. chejuensis, as named by Johnson and Jones(1955). Furthermore, it is confirmed that large-size specimens from Wando island is subspecies A. a. chejuensis, as suggested by koh (1989). In future, analyses with specimens from islands in southern coasts are necessary to clarify the taxonomic status of Apodemus agrarius in Korea.

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Biological Characteristics and Preservation of Dokdo Island

  • Kim, Ki-Tai
    • The Korean Journal of Ecology
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    • v.25 no.1
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    • pp.59-62
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    • 2002
  • Dokdo, which is located in the middle of the East Sea, is a small island tilth a total area of 0.186 $\textrm{km}^2$. However, this small island, with its mild oceanic climate, has rich bio-resources and picturesque natural surroundings. Dokdo in the crystaline waters and In the central area of the deep sea is a treasury of algaes (sea oak, sea mustard, gulf weed, laver, agar-agar, etc.), molluscs (squid, ear shell, conch, etc.) and fishes (Alaska pollack, anchovy, saucy, herring, etc.). On the other hand, there are a lot of grasses and various kinds of grasses on the land of Dokdo. And a lot of back-tailed gulls (about 20,000 Individuals) live on this island. There have been disputes on the sovereignty over Dokdo between Korea and Japan. Japan has claimed sovereignty over Dokdo since Japan incorporated the island into Japanese territory in 1905 when it occupied the Korean Peninsula by force. Korea governed Dokdo not only before 1905 but also after its liberation in 1945. The Korean government, while heavily financing building facilities like pleas and quays, is endeavoring to preserve the natural surroundings of this island.

Evaluation of Energy Production for a Small Wind Turbine Installed in an Island Area (도서지역 소형풍력발전기 에너지 발생량 평가)

  • Jang, Choon-Man;Lee, Jong-Sung;Jeon, Wan-Ho;Lim, Tae-Gyun
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.6
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    • pp.558-565
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    • 2013
  • This paper presents how to determine AEP(Annual Energy Production) by a small wind turbine in DuckjeokDo island. Evaluation of AEP is introduced to make a self-contained island including renewable energy sources of wind, solar, and tidal energy. To determine the AEP in DuckjeokDo island, a local wind data is analyzed using the annual wind data from Korea Institute of Energy Research firstly. After the wind data is separated in 12-direction, a mean wind speed at each direction is determined. And then, a small wind turbine power curve is selected by introducing the capacity of a small wind turbine and the energy production of the wind turbine according to each wind direction. Finally, total annual wind energy production for each small wind turbine can be evaluated using the local wind density and local energy production considering a mechanical energy loss. Throughout the analytic study, it is found that the AEP of DuckjeokDo island is about 2.02MWh/y and 3.47MWh/y per a 1kW small wind turbine installed at the altitude of 10 m and 21m, respectively.

Water Quality Improvement by Artificial Floating Island (인공섬을 이용한 소형 저수지의 수질 개선)

  • Park, Hyun-Jin;Kwon, Oh-Byeong;Ahn, Tae-Seok
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.1
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    • pp.90-97
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    • 2001
  • For improvement of water quality, $20m^2$ of artificial floating plant islands planted with Iris pseudoacorus, were installed in small pond on March, 1999. Small pond has surface area $1,000m^2$ and mean depth 1.5 m. The density of plants was 16 per $m^2$ by using jute pot. Environmental parameters such as COD, SS, T-N, T-P and planktons were biweekly measured from 29 March to 28 September. Because of the small portion of floating island, the effect for water quality improvement was not sufficient. But considering the data of plant growth and nitrogen and phosphorus uptake capacity of plant, about 40% of coverage by artificial floating island was needed for elimination of whole nutrients from inflow.

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Connection between a Small-Scale Emerging Island and Double Arc Loops Producing a M6.5 Flare in Active Region 12371

  • Kang, Jihye;Inoue, Satoshi;Moon, Yong-Jae;Magara, Tetsuya;Kusano, Kanya
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.81.3-81.3
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    • 2017
  • In this paper, we report a small-scale emerging island and double arc loops, which are associated with a M6.5 flare, in Active Region 12371. We investigate the spatial and temporal changes of both photospheric magnetic fields using SDO/HMI data and coronal magnetic structures obtained from nonliner force-free field (NLFFF) extrapolation. From the vector magnetograms, we find a small-scale emerging island near the main polarityy inversion line about three hours before the flare. The island has a strong shear angle, which is determined by difference between transverse component of observed field and potential field, of around 90 degrees. Furthermore, the NLFFF well reproduces a sigmoidal structure seen in SDO/AIA 94, which is consistent with the double arc loops configuration suggested by Ishiguro and Kusano (2017) who introduced a magnetic configuration showing the double arc instability. The observed emerging island is located among the double arc loops, which is also supproted by their model. Finally, there was an eruption (M6.5 flare) associated with the loops. We discuss a possible role of the double arc instability for the eruption.

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