• Title/Summary/Keyword: Rock pool

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An Analysis of Ecological Habitat Characteristics in Medium-scale Stream -A Case of the Bokha Stream- (중규모 하천 생물 서식처의 특성 분석 -복하천을 중심으로-)

  • 안홍규;우효섭
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.2
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    • pp.102-119
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    • 2004
  • This study investigates the relation between the location of a habitat and the ecological connections according to the habitat type in the riparian zone at the Bokha stream. Stream habitat is classified into nine types for the aquatic insects and fish. For vegetation and birds, habitat is classified into five types of medium-scale streams, including both physical and chemical streams are analyzed accordingly. The major results of this study are as follows: 1) A pool connected to the main stream has a certain water depth (about 80 cm) and is disturbed at least 5 to 6 times a year. Although the pool has a somewhat bad water quality, it provides a habitat for various types of young fish. 2) A meander riffle is about 15 cm deep, the flow velocity in the region is about 75 cm/s. This region does not have large structures to which aquatic insects can attach, so it cannot be used as a spawning ground. 3) A rock type pool is about 60 cm deep, the flow velocity in the meander riffle is about 25 cm/s. In this region, many aquatic insects attached to large structures appear. Due to various riparian vegetation, the rock type pool is used as a habitat for aquatic insects. 4) A pool which is only connected to the main stream during floods has a bad water quality. Despite of its relatively small size, it has a high population density of aquatic insects. faculty.

Characteristics of step-pool structure in the mountain streams around Mt. Jiri (지리산 주변 산지하천의 step-pool 구조 특성)

  • Kim, Ki Heunga;Jung, Hea Reyn
    • Journal of Korea Water Resources Association
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    • v.51 no.4
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    • pp.313-322
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    • 2018
  • The height of the steps was almost the same as the grain size of bed materials and increased with channel slope. The step widths and step wavelengths are almost the same size, and the step wavelength was decreased when the channel slope was increased. It was analyzed that there was a clear correlation between channel width and step width, and the step width increases with channel width. In addition, the step wavelength was scaled by channel width, and the step height is governed by the grain size of the rock forming the step, so that the profile structure of the step-pool was changed according to the channel slope. the scale of the pool was found to be highly correlated with the channel width, grain size, and slope gradient. Therefore, the characteristics of step-pool structure in mountain streams were influenced by various factors, but it can be explained as the grain size, channel width and channel slope.

The Characteristic of Fish Fauna by Habitat Type and Population of Zacco platypus in the Tan Stream (탄천의 서식처별 어류상과 피라미 개체군의 특징)

  • Choi, Jun-Kil;Jang, Chang-Ryeol;Byeon, Hwa-Kun
    • Korean Journal of Environment and Ecology
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    • v.25 no.1
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    • pp.71-80
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    • 2011
  • The fish fauna and characteristics of population of Zacco platypus in the 9 microhabitat at the Tan Stream was investigated from August, 2009 to April, 2010. The collected species during the survey period were 17 species belong to 7 families. Korea endemic species were Hemiculter eigenmanni and Odontobutis interrupta, which showed a ration of 11.8% in collected species. Dominant species was Z. platypus and subdominant species was Carassius auratus. Dominated species of C. auratus was at the dam-type pool, Meander-type pool, run, and rock-type pool, Pseudogobio esocinus was side channel, Rhinogobius brunneus was riffle, and Z. platypus was channel connected pool, substrate-type pool and channel unconnected pool. Length-weight relationship in the population of Z. platypus was 3.29. PCA analysis was in to the 3 groups identified. Bary-curtis cluster analysis indicated that the substrate-type pool and channel unconnected pool 65.9% showed the most similar, riffle, and dam-type 30.4% were identified as the most contrast.

Form, Function and Longevity in Fucoid Thalli: Chlorophyll a Fluorescence Differentiation of Ascophyllum nodosum, Fucus vesiculosus and F. distichus (Phaeophyceae)

  • Kim, Kwang-Young;Garbary, David j
    • ALGAE
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    • v.24 no.2
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    • pp.93-104
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    • 2009
  • Imaging-PAM fluorometry was used to assess the chlorophyll a fluorescence parameter ${\Phi}_{PSII}$ (effective quantum yield) in Frcus vesiculosus. F. disttchus. ssp. distichus and AscophyIIum nodosum. The objective was to show variadon in fluorescence yield associated with age and frond organ, and to illustrate the spatial scales at which photosynthetic parameters vary on fucoid thalli. In addition, our species represented taxa in different but related genera, species with different ecoloeies (rock pool and non rock pool species), morphologies (with and without air bladders) and longevities (several to 20 or more years). A further objective was to determine the extent to which photosynthetic parameters reflected these differences- Effective quantum yield declined substantially with age in F. vesiculosus and F. distichus ssp. distichus, whereas ${\Phi}_{PSII}$ in A. nodosum was maximal after three years. In A. nodosum ${\Phi}_{PSII}$ was still high in branch segments at least seven years old. Older branches of A. nodosum showed relatively higher and more homogeneous photosynthetic capacity relative to Fucus species. Surfaces of air bladders in A. nodosum and F. vesicu- losus had ${\Phi}_{PSII}$ that was not significantly different from the highest rates, achieved in these species. The heterogene- ity of photosynthetic efficiency is consistent with morphological and developmental differences among the species and their ecology. in particular the longevity of A. nodosum fronds.

An Experimental Study on the Effect of Longitudinal Ventilation on the Variation of Burning Rate in Tunnel Fires (터널 화재시 종류식 환기가 연소율 변화에 미치는 영향에 관한 실험적 연구)

  • Yang Seung Shin;Kim Sung Chan;Ryou Hong Sun
    • Tunnel and Underground Space
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    • v.15 no.1 s.54
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    • pp.55-60
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    • 2005
  • In this study, the 1/20 reduced-scale experiments using Froude scaling were conducted to investigate the effect of longitudinal ventilation on the variation of burning rate in tunnel fires. The methanol square pool fires with heat release rate ranging from 3.57 kW to 10.95 kW were used. The burning rate of fuel was obtained by measured mass using load cell and temperature distribution were measured by K-type theomocouples in order to investigate smoke movement. The wind tunnel was connected with one side of the tested tunnel, and logitudinal ventilation velocity in the tested tunnel was controlled by power of the wind tunnel. In methanol fire case, the increase in ventilation velocity decreased the turning rate due to the direct cooling of fire plume. For the same dimensionless velocity(V), homing rate decreased as the size of pool fire increased.

Characteristics of Fish Community in Gap Stream by Habitat Type (서식처 유형에 따른 갑천의 어류군집 특성)

  • Lee, Dong-Jun;Byeon, Hwa-Kun;Choi, Jun-Kill
    • Korean Journal of Ecology and Environment
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    • v.42 no.3
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    • pp.340-349
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    • 2009
  • The natural type section of Gap Stream was divided into 7 sites, such as, closed pool, runs, riffle, opened pool, pool, reek-scattered riffle, and Dam-type pool. The ecological characteristics of fish community at each site was examined from April, 2007 to October, 2008. During the survey period, 29 species belonging to 8 families were collected, and Carassius auratus (St. 1), Coreoleuciscus splendidus (St. 3), Acheilognathus lanceolatus (St. 4) and Zacco platypus (St. 2, 5, 6, 7) were characteristic species that represent each habitat. The species of C. auratus preferred physical habitat with sand-bottom pool, moderate depth of 65$\sim$90 cm, and stagnant water. The species of C. splendidus mainly preferred physical habitat with cobbles and pebbles are scattered riffles (St. 3), moderate depth of 65$\sim$90 cm, and flow velocity is 0.14$\sim$0.85 m $sec^{-1}$. It also preferred where concentration of BOD, COD, TN, TP and SS is low and DO's value is high, because the flow velocity is fast. A. lanceolatus preferred where the depth of water is low (3$\sim$44 cm) like an opened pool (St. 4) and the flow velocity is slow (0.01$\sim$0.02 m $sec^{-1}$). Z. platypus dominated in a variety of habitats such as runs (St. 2), pool (St. 5), rock-scattered riffles (St. 6) and D-type pool (St. 7), and it preferred places where flow is abundant and riverbed structure is diverse. On the other hand, 4 individuals of Iksookimia choii appeared at reek-scattered riffles (St. 6). I. choii appeared in this research lived in where the width of river is 24 m, the depth of water is 3$\sim$35 cm and the flow velocity is 0.01$\sim$0.49 m $sec^{-1}$, and riverbed structure was diversely formed with boulder to sand. Also, water temperature, EC, BOD, COD, TN and TP was low, but concentrations of DO and SS were high comparatively. Therefore, it seems that I. choii can live only in physical and chemical environment with similar conditions.

The Characteristics of Fish Fauna by Habitat Type and Population of Zacco platypus in the Hongcheon River (홍천강의 서식처 유형별 어류상과 피라미 개체군의 특징)

  • Lee, Hwang-Goo;Jang, Chang-Ryeol;Choi, Jun-Kil
    • Korean Journal of Environment and Ecology
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    • v.27 no.2
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    • pp.230-240
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    • 2013
  • The fish fauna and population characteristics of Zacco platypus at the 9 habitat types in the Hongcheon River were investigated from August, 2009 to April, 2010. The collected species during the surveyed period were 21 species belong to 6 families. Korea endemic species were Acheilognathus signifer, Microphysogobio longidorsalis, Pseudopungtungia tenuicorpa, Squalidus gracilis majimae, Zacco koreanus, Iksookimia koreensis, Silurus microdorsalis, Liobagrus andersoni, Coreoperca herzi, Odontobuitis interrupta, and Odontobuitis platycephala which showed 61.9% ratio of total species. Dominant species was Z. koreanus, and subdominant species was Z. platypus. Dominant species according to habitat types were Z. platypus(in side channel, substrate type pool, and riffle), Z. koreanus(channel connected pool, run, meander type pool, and rock type pool), M. yaluensis( dam type pool ) and Rhynchocypris oxycephalus(channel unconnected pool). Length-weight relationship in the population of Z. platypus was 3.27 in regression coefficient(b). Principal component analysis was classified as 2 groups. Bray-curtis cluster analysis indicated that the channel connected pool and meander type pool showed the most similar values(66.2%), whereas side channel and channel unconnected pool exhibited the most distance values(32.1%).

The Distribution Characteristics of Fish Community by Habitat Type in the Nonsan Stream (논산천의 서식처 유형별 어류군집의 분포특성)

  • Lee, Hwang-Goo;Choi, Jun-Kil
    • Journal of Wetlands Research
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    • v.16 no.3
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    • pp.303-313
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    • 2014
  • The spatial distribution characteristic of fish community were investigated at the 10 habitat types in the Nonsan stream from August, 2008 to June, 2009. The collected species during the surveyed period were 26 species belong to 6 families. Korean endemic species were Sarcocheilichthys nigripinnis morii, Squalidus japonicus coreanus, Hemiculter eigenmanni, Pseudobagrus koreanus, and Odontobutis interrupta which showed 19.2% ratio of total species. Dominant species was Zacco platypus, and subdominant species was Tridentiger brevispinis. Dominant species according to habitat types were Micropterus salmoides(substrate type pool and rock type pool), Lepomis macrochirus(channel connected pool and channel unconnected pool/abandoned type pool), T. brevispinis(channel unconnected pool/overflow type and run) and Z. platypus(riffle, meander type pool, side channel, and dam type pool). As a results of community analysis in side channel, diversity index showed relatively high values, indicating that habitat types in the Nonsan stream have relatively stable community structure. Bray-curtis cluster analysis indicated that the meander type pool and riffle showed the most similar values(80.8%). Moreover, cluster and principal component analysis were classified as 2 groups(lotic and lentic habitats).

Traditional Korean landscape garden with special attention (역사적 문화환경의 창조 -고대정원문화를 중심으로-)

  • 민경현
    • Journal of the Korean Professional Engineers Association
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    • v.18 no.2
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    • pp.54-65
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    • 1985
  • Korean Landscape Garden may be described according to its stage of development. In the primitive agricultural era, the garden was preceded by vegetable yards and at this time rock arranging (Soo-Sok garden) was initiated together with the megalithis culture of dolmens, heavenly altars and tumuli. In the early Three Kingdom period palace gardens were built on a grand scale and toward the end of fourth century temple garden were introduced along with Buddhism. These gardens evolved to the flourishment of "HWAGE"(terraced gardens) rock arrangements of ZEN, early KOR-YO period. Especially since the middle of KOR-Yo period the "IM-CHUN"(forest and pond) garden became popular, while during Cho-Son period "HWAGE" in the back yard, pond and pool garden and "IM-CHUN" style country villa became fashionable. The Korea traditional Landscape garde may be characterized that first it is a nature Landscape style, which makes the maximum accomodation with the surrounding nature. Secondly, the Korean garden is built creatively by utilizing the elements of its climate and topography, Kogu-Ryo, Paik-Je great-Kaya and Sil-Ra had developed original a castle town plans and beautiful gardens rock arrangements which precede the equivalent style of China and set the prototype for Japan. The Landscape art of waterfalls and rock arrangements at An-Ap-Chi garden of 7th century has no equals in China and set the origin of pond style of Japanese garden.

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A Study on the Application of Ventilation Equipment in an Underground Fire (지하공간 화재시 배연장비의 활용에 관한 연구)

  • Lee, Sung-Ryong;Han, Dong-Hoon
    • Tunnel and Underground Space
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    • v.20 no.2
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    • pp.92-96
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    • 2010
  • In this study, experiments were conducted to evaluate the effectiveness of ventilation equipment in underground fires. Two type of Ventilators were used in experiments. Experiments were carried out using ethanol square pool fire. Maximum heat release rate was about 460kW. Visibility and temperature distribution were evaluated according to mechanical ventilation. In blower type ventilation, visibility was increased and temperature was lowered.