• Title/Summary/Keyword: Stream of Island

Search Result 138, Processing Time 0.024 seconds

Microhabitat Characteristics of the Korean Endemic Cobitid Species Iksookimia hugowolfeldi Inhabited at Geogeum Island and Jangheung-gun in Korea (거금도와 장흥에 서식하는 한국고유종 남방종개 Iksookimia hugowolfeldi의 미소서식처 특성)

  • Park, Cheol Woo;Kim, Hyeong Su;Kim, Jae Goo;Yun, Seung Woon;Kim, Hyun Tae;Park, Jong Sung;Choi, Woong Sun;Cho, Yun Jeong;Park, Jong Young
    • Korean Journal of Ichthyology
    • /
    • v.28 no.1
    • /
    • pp.35-40
    • /
    • 2016
  • The microhabitat of Iksookimia hugowolfeldi was surveyed in two sites, Geogeum Island and Jangheung. I. hugowolfeldi in Geogeum Island inhabits mainly pool. This water system consists of sand and cobble and has a shallow water (0.1~0.8 m depth) with slow currents (0.1 m/s). 0+ years old inhabits pool consist of sand and lives in a less than 0.3 m depth. I. hugowolfeldi in Jangheung population inhabits mainly pool consists of sand and cobble and lives in a shallow water (0.1~0.8 m depth) with slow currents (0.1 m/s) compared to the stream of Geogeum Island. With some different fish species, sympatric species collected at Geogeum Island and Jangheung population are 7 species in 4 family identically in the two sites.

A Study of Environmentally Friendly Residential District Development -Concentrated on Gang-buk new town residential district- (친환경 주거단지 개발계획에 관한 이론적 고찰 -강북뉴타운 주거단지를 대상으로-)

  • Kil, Ki-Seok
    • KIEAE Journal
    • /
    • v.4 no.3
    • /
    • pp.53-63
    • /
    • 2004
  • According to the New Town Development Plan, Gang-buk area, a symbol of slum in Seoul will be changed new residential area. There are a lot of challenges for success this project. First of all, new ways of city plan "pre-plan and development" and "environmentally friendly development" are necessary to carry out this plan. Another important idea is how to overcome conflicts such as unbalanced development, a traffic jam and environment problem. Also, Government and a citizen agree that this project have to accept eco-protectable and sustainable development theory. For increasing green area ratio and keeping eco-diversity, planting at roofs and water circulation system in residential complex are compulsory. Green network based on environmentally friendly development provides a natural energe stream on eco-system and protects a city from air pollution, hot air island phenomenon and a flood.

New Record of a Freshwater Hydra and a Marine Hydromedusa(Cnidaria, Hydrozoa) in Korea (한국미기록 담수한 히드라류 1종 및 해산 히드라해파리류 1종 (자포동물문, 히드라충강))

  • Park, Jung-Hee
    • Animal Systematics, Evolution and Diversity
    • /
    • v.17 no.1
    • /
    • pp.13-19
    • /
    • 2001
  • Hydra and hydromedusa specimens were collected from the Jisanchon Stream in Kyonggi-do (Pyongtaek-shi) and the coasts of Geojedo Island (Jangmok-ri), Korea during the period July 1999-June 2000. They were identified into Hydra magnipapillata Ito, 1947 (Hydridae, Athecatae) and Phialidium folleatum (McCrady, 1857) (Campanulariidae, Leptomedusae) respectively. H. magnipapillata is blackish or light brown color, its cylinder-shaped trunk reaches to 20 ㎜ long and 0.5-0.6 ㎜ wide in fully extended, and has generally 5-6 highly delicate long tentacles. P. folleatum is a small marine hydromedusa, below 5 ㎜ wide and has a minute statocyst between successive tentacles.

  • PDF

Effects of Artificial Vegetation Island on Fish Fauna (인공수초섬이 어류상에 미치는 영향)

  • Byeon, Myeong-Seop;Park, Hae-Kyung;Jeon, Nam-Hui;Choi, Myeong-Jae;Kong, Dong-Soo
    • Korean Journal of Ecology and Environment
    • /
    • v.40 no.1
    • /
    • pp.103-109
    • /
    • 2007
  • To investigate the effects of artificial vegetation island (AVI) on fish distribution, we compared fish fauna from artificial vegetation island (AVI) area, which installed in 2000, natural vegetation area (NVA) and vegetation-free area (VFA) at Kyungan Stream area of Lake Paldang from Jul. to Nov., 2005. Results showed that 11 families 23 genera 24 fish species were distributed in the AVI and NVA. Squalidus japonicus coreanus, a small-size fish which generally lives at the downstream, dominated absolutely in the individual numbers. However, only 6 families 11 genera 12 species of fishes caught at the VFA, and dominant fishes were Hemibarbus labeo and Erythroculter erythropterus, a medium to large-size migratory fishes which live in mid-depth of water column. The dominance index was high at the AVI (0.778) and NVA (0.868), whereas the diversity index and evenness index were high at the VFA. Fish distribution at AVI was similar to that of the NVA in numbers of species, indicating that the AVI could playa role as spawning and inhabitation zone to a variety of fishes. We believe that AVI may be used for a restoration of the damaged and disturbed littoral ecosystem.

Geochemical Characteristics of Groundwater for Dry and Rainy Seasons in Ddan-sum Island (갈수기와 홍수기의 김해 딴섬지역 지하수의 지구화학 특성)

  • Kim, Gyoobum;Jeon, Hangtak;Shin, Seonho;Park, Joonhyeong
    • Journal of the Korean GEO-environmental Society
    • /
    • v.13 no.9
    • /
    • pp.31-44
    • /
    • 2012
  • Seasonal changes in groundwater geochemistry exist in Ddan-sum island. In the farming season of April, the spatial distribution of ions explains that $Fe^{2+}$, Fe(total), $Mn^{2+}$, $Ca^{2+}$, $Mg^{2+}$, $SiO_2$, ${HCO_3}^-$, and ${NO_3}^-$ are high in the center of the island, but $Na^+$ and $K^+$ are relatively low and these high anions indicates the effect of fertilizer used for strawberry cultivation. Spatial variation of ion concentration is smaller in August than April because of low agricultural activity and heavy rainfall. Geochemical type of groundwater shows that the center of island has the characteristics of recharge zone but the rim area corresponds to a mixing zone between groundwater and stream water. According to the analysis of saturation index for Fe and Mn ions, hematite, goethite, and rhodochrosite under supersaturation have a possibility of additional mineral deposition, and siderite, $Fe(OH)_3$, manganite, pyrolusite, and pyrochroite under unsaturation may exist as a type of dissolved ion.

Freshwater Fish Fauna and Community Structure of the Small Streams in Bogil Island, Korea (보길도 소하천 담수어류상 및 군집구조)

  • Han, Jeong-Ho;Park, Chan-Seo;An, Kwang-Guk;Paek, Woon-Kee
    • Korean Journal of Environment and Ecology
    • /
    • v.31 no.1
    • /
    • pp.72-80
    • /
    • 2017
  • Fish fauna and community structures in freshwater were analyzed in the streams (12 stations) of the Bogil Island from May to September 2015. Total numbers of the sampled species and genus (9 families) were 21 and 17, respectively. Gobiidae was the most dominant taxa, which accounted for 47.6% (10 species) of the total species, and the relative abundance, based on the number of individuals, was 60.4% (1,157 individuals). Subdominant families were three taxa of Cyprinidae (3 species; 500 ind.), Mugilidae (2 species; 168 ind.) and Mugilidae (2 species; 128 ind.). The dominant species, based on the relative abundance, was Rhynchocypris oxycephalus (20.7%) and the subdominant species were Gymnogobius urotaenia (19.5%), Leucopsarion petersii (17.2%) and Chelon haematocheilus (8.5%). These species were composed of upstream-resident fish as well as migratory fishes, so the streams of the Bogil Island had unique characteristics in the fish compositions. Based on all the species sampled, 9 species (42.9%) were primary freshwater fishes, 11 species (52.4%) were peripheral fishes and 1 species (4.8%) was amphidromous fish. Korean endemic species and exotic species were not found in the streams of Bogil Island. According to the analysis of fish community structure, species richness index and species diversity index were highest (1.831, 1.957) in the Site 8 and lowest in the Site 4. In the meantime, the dominance index was highestin the Site 4 (1.00) and lowest in theSite 8 (0.17).

Complementary Relationship Based Evaportranspiration Estimation Model Suitable for the Hancheon and Kangjeongcheon Watersheds in Jeju Island (제주 한천 및 강정천 유역에 적합한 보완관계법 기반 증발산량 산정 모형)

  • Kim, Nam Won;Nah, Hanna;Lee, Jeongwoo;Lee, Jeong Eun
    • Journal of Korea Water Resources Association
    • /
    • v.47 no.12
    • /
    • pp.1155-1163
    • /
    • 2014
  • The complementary relationship-based evapotranspiration models, namely, AA model of Brutsaert and Stricker (1979) and the CRAE model of Morton (1983) was applied to two permanent stream watersheds Jeju island for the first time, and their major optimal parameters were suggested in this study. The representative watersheds for model calibration and validation were selected as the Hancheon watershed located in the northern part of the Jeju island and and the Kangjeongcheon watershed in southern Jeju island, respectively. The estimated actual evapotranspiration for the Hancheon watershed was compared with the result by the hydrological model, and the major parameters of the AA and CRAE models were calibrated until their results match the hydrological simulations. Through the iterative estimations, the optimal parameters were determined as ${\alpha}=1.00$, $M=30.0Wm^{-2}$ of the AA model, and $b_1=33.0Wm^{-2}$, $b_2=1.02$ of the CRAE model. The calibrated AA and CRAE models were applied to the Kangjeongcheon watershed for model validation, and it was found out that both models can accurately produce the actual evaporation on annual and semiannual bases.

Regional Trend Analysis for Groundwater Quality in Jeju Island - Focusing on Chloride and Nitrate Concentrations - (제주도 지하수 수질의 광역적 추세 특성 분석 - 염소 및 질산성질소를 대상으로 -)

  • Kim, Gyoo-Bum;Kim, Ji-Wook;Won, Jong-Ho;Koh, Gi-Won
    • Journal of Korea Water Resources Association
    • /
    • v.40 no.6 s.179
    • /
    • pp.469-483
    • /
    • 2007
  • Nitrate and chloride are the most common contaminants in groundwater and their concentrations increase easily due to fertilizer consumption and urbanization. The number of time series data for groundwater quality at a single site was not sufficient to analyze trends on Jeju Island. Therefore rectangle grids were drawn for the whole island and single grid was determined to be $500m{\times}500m$ after considering similar stream density, homogeneous hydraulic coefficients, geologic features of volcanic rock and low topographic slopes. All data within each lattice were collected and arranged in time series order and analyzed using Sen's method. 10.6 % of the total lattices for chloride and 22.4% for nitrate showed upward trends from the early 1990's to the early 2000's. Especially, upward trends for nitrate concentration are distinct in the low mid-mountainous areas of western and southern watersheds. Many septic tanks and much domestic waste from the urbanization of the low mid-mountainous area have produced this upward trend. Additionally, the agricultural region has dramatically increased since the 1990's and this has led to an increase of fertilizer consumption and, as a result, nitrate concentration. Therefore, the target of any management plan for groundwater quality on Jeiu Island needs to be focused on careful land use decisions in the mid-mountainous areas which are near Halla Mountain.

Channel Migration of Byeongmun River Caused by Roof Collapse of Gurin Cave in Mount Halla, Jeiu Island (한라산 구린굴의 천장 함몰로 인한 병문천의 유로 변경)

  • Kim, Tae-Ho;An, Jong-Gi
    • Journal of the Korean Geographical Society
    • /
    • v.43 no.4
    • /
    • pp.466-476
    • /
    • 2008
  • Gurin Cave, 442 m long, is a lava tube developed on the northern slope of Mount Halla. Seventy-three meters of its lower reach became a river channel since Byeongmun River flowed into a window after roof collapse took place. The subterranean channel has a width of 447 cm and a height of 501 cm, respectively. Its banks show well-developed lava shelves of a typical lava tube, while its floor has sculpted forms which characterize a bed of a bedrock stream. The reach is likely to be collapsed and then has four collapsed windows since its roof has the densely developed testudinal joints and consists of thin lavas with a thickness of 30 to 60 cm. Before the subterranean channel appeared, a ground channel flowed over the cave and joined into a main channel of Byeongmun River at 653 m in altitude. However, the subterranean channel substituted the ground channel since a bed of the ground channel collapsed into the cave. The new channel, flowing through the cave, joined into a main channel at 660 m in altitude. As the drainage area of Byeongmun River expanded upstream the cave, the new channel changed into a main channel. Since floodwater flows down the ground channel as well as the subterranean channel, a distributary stream has temporarily appeared at the collapsed window. Lava tubes are likely to have an affect on the development of river system in Jeiu Island, in that the caves have constantly shown roof-fall.

Application of In-situ Produced Cosmogonic $^{10}$ Be and $^{26}$ Al for Estimating Erosion Rate and Exposure Age of Tor and Block Stream Detritus: Case Study from Mt. Maneo, South Korea (우주기원 방사성 핵종을 이용한 만어산 암설지형의 침식률 및 노출연대 측정)

  • Yeong Bae Seong;Jong Wook Kim
    • Journal of the Korean Geographical Society
    • /
    • v.38 no.3
    • /
    • pp.389-399
    • /
    • 2003
  • CRN (Cosmogenic radionuclide) methodology has been a versatile tool applicable to a wide range of geomorphology. This study was underiaken to ascertain the rate of erosion and exposure age of mountain-top detritus (tors and block streams) on Mt. Maneo by employing the concentrations of in-situ produced cosmogenic $^{10}$ Be and $^{26}$ Al from bedrock surfaces that are exposed to cosmic rays. The results suggest that tors on the summit were positioned here during the glacial period but no later than 65ka and block streams have been stabilized also since the last glacial period but no later than 38ka. The tors on the summit have been eroded at a slower rate (9m/Ma) than blocks on the hillslope (15m/Ma) since the initial abrupt exposure of each landform to cosmic rays, suggesting that there is a slight difference in the rate of erosion between the summit and the hillslope, and that the local relief between the two areas has been increased. When the $^{26}$ Al/$^{10}$ Be-$^{10}$ Be concentrations from samples are plotted in Lal's steady-state erosion island, one sample (from a for) has complex exposure histories, which can be explained by the occurrence of multiple chipping event of 5cm to 60cm in length on the surface of the rock.