• Title/Summary/Keyword: 유입유사

Search Result 728, Processing Time 0.032 seconds

Fish Fauna and Community Structure in Yulcheon Stream of South Korea (율천의 어류상과 어류군집구조의 분석)

  • Yoo, Su-Hyang;Kim, Jae Goo
    • Korean Journal of Ichthyology
    • /
    • v.33 no.4
    • /
    • pp.297-303
    • /
    • 2021
  • In this study, nine major sites of Yulcheon stream, a principal tributary of the Seomjingang River, were surveyed from April 2020 to October 2020, and their fish fauna and community structure were analyzed. A total of five families and 19 species of fish were identified. Among the 19 species, seven species were found to be endemic to Korea: Rhodeus uyekii, Squalidus gracilis majimae, Microphysogobio yaluensis, Odontobutis interrupta, Cobitis tetralineata, Zacco koreanus, and Squalidus chankaensis tsuchigae. Among five families, the family Cyprinidae had the largest number of species (15), whereas the rest of the four families: Gobiidae, Odontobutidae, Cobitidae, and Osphronemidae, had one species each. The two dominant species in the family Cyprinidae were identified as Z. platypus and Z. temminckii. The community index of nine major sites of Yulcheon stream was 0.499 dominance, 2.279 diversity, 0.774 evenness, and 2.594 species richness. The number 3 site had 14 species, the largest number of species among all sites, and the dominance rate (0.480) was low, whereas diversity (2.173), and species richness (2.701) were the highest. As a result of cluster analysis, clusters matched according to the structure of the river types, but St. 9, which confirmed a relatively small number of populations, showed a structure similar to that of the upstream section. In the case of St. 5, a separate cluster was formed by a large number of species and populations.

Effects of Physicochemical and Environmental Factors on Spatial and Temporal Variations in Phytoplankton Pigment and its Community Composition in Jinhae Bay (진해만에서 물리화학적 환경요인이 식물플랑크톤 색소 및 군집조성의 시공간적 변화에 미치는 영향)

  • Na, Sujin;Lee, Jiyoung;Kim, Jeong Bae;Koo, Jun-Ho;Lee, Garam;Hwang, Hyunjin
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.27 no.2
    • /
    • pp.340-354
    • /
    • 2021
  • The aim of this study was to investigate the spatial and temporal distribution of phytoplankton biomass and community composition in Jinhae Bay on the southern coast of Korea. Phytoplankton pigment analysis was conducted using ultra performance liquid chromatography (UPLC) were conducted from April to December 2019 at seven stations. Temperature, salinity, and dissolved oxygen (DO) and inorganic nutrients (dissolved nitrogen, dissolved phosphorus, and orthosilicic acid) were measured to investigate the environmental factors associated with the structure of phytoplankton community. Phytoplankton biomass (Chl-a) was the highest in July (mean 15.4±4.3 ㎍/L) and the lowest in December (mean 3.5±0.6 ㎍/L). Fucoxanthin was the most abundant carotenoid and showed a similar variation pattern to Chl-a, peridinin, and Chl-b. Phytoplankton community composition analysis showed that diatoms were a predominant group with an average abundance of 70 % whereas chlorophytes, cryptophytes, and dinoflagellates often appeared with lower averages. Further, the dominance of diatoms was closely correlated with water temperature and N:P ratio, which might be influenced by high temperatures in the summer and nutrient loading from the land. Additionally, freshwater and nutrient input by rainfall was estimated to be the most important environmental factor. Hence, the spatial and temporal variations in the composition of phytoplankton pigments and phytoplankton community were correlated with physicochemical and environmental parameters.

Bacterial Distribution and Relationship with Phytoplankton in the Youngsan River Estuary (영산강 하구의 박테리아 분포 및 식물플랑크톤과의 관계)

  • Kim, Se Hee;Sin, Yong Sik
    • Journal of Marine Life Science
    • /
    • v.4 no.2
    • /
    • pp.53-62
    • /
    • 2019
  • Heterotrophic bacteria are a major member of the microbial loop in the marine ecosystem and play an important role in the biogeochemical cycle decomposing organic matter. Therefore study of bacterial variation is important to understand the material cycle and energy flow of marine ecosystems. We investigated the monthly variations of bacteria and environmental factors in the Youngsan River estuary, and the correlation between bacteria and phytoplankton biomass (chlorophyll-a) including size-structure. As a result, bacteria of the Youngsan River estuary were higher in the surface than in the bottom layer, and higher in the summer than in winter. And the closer to the dike, the abundance increased, and it increased to the peaks in August, September, and June 2019 at the station closest to the dike. The chlorophyll-a also increases at the stations and time when the bacterial abundance was high and they correlates positively displaying no difference between size fractions. The results indicate that organic matter derived from phytoplankton has an effect on bacterial variation but no size-dependent effects. In addition, the seasonal pattern of bacteria increasing in proportion to the water temperature suggests the effect of water temperature on the growth of bacteria. No association of bacterial abundance variation with nutrient supply due to freshwater input was observed. In this study, dissolved oxygen was depleted and hypoxia was observed for a short time when a strong stratification was not developed. This may be resulted from the supply of organic matter from phytoplankton and the consumption of oxygen due to bacterial decomposition.

Species Composition and Assemblage Structure of Fish Collected by Set Net at the Coastal Waters of Goseong in Gangwon-do, Korea (강원도 고성연안에서 정치망으로 채집된 어류 종조성과 군집구조)

  • Lee, Soo Jeong;Yang, Jae-Hyeong;Seo, Young Il;Kim, Jin-Koo
    • Korean Journal of Ichthyology
    • /
    • v.33 no.2
    • /
    • pp.95-106
    • /
    • 2021
  • In order to understand the seasonal variations of species composition of fish in the Goseong, middle East Sea of Korea, we surveyed fish fauna using set net during 2 years. In this study, a total of 77 taxa belonging to 40 families were collected and 75 species were identified. The dominant family were Tetraodontidae and Pleuronectidae, and the dominant species were Arctoscopus japonicus, Konosirus punctatus, Stephanolepis cirrhifer, Thamnaconus modestus, and Trachurus japonicus. The results of the hierarchical clustering using the number of individuals of collected species showed that they are divided into three seasonal groups: Group A (Jan.~Apr.), Group B (May~Jun., Nov.~Dec.), Group C (Jul.~Oct.). The sea surface temperature (SST) was higher than the results of previous studies in winter and spring, and species composition in spring have changed from cold-water species to the warm-water species, recently. The species composition has become similar to the that of southern Gangwon-do regions (Samcheok and Gangneung) of the previous studies. The species diversity of family Tetraodontidae has increased, which is estimated to have an effect on increase in SST and the quantity of entering the East Sea. Therefore, we assumed that the change of species composition is related to the extension of northern distribution limits and survival temperature, and abundant preys. Therefore, it is necessary that an efficient resource management policy as well as the ways of commercially use of migratory warm-water fish, rapidly.

Analysis on the Changes in Abandoned Paddy Wetlands as a Carbon Absorption Sources and Topographic Hydrological Environment (탄소흡수원으로서의 묵논습지 변화와 지형수문 환경 분석)

  • Miok, Park;Sungwon, Hong;Bonhak, Koo
    • Land and Housing Review
    • /
    • v.14 no.1
    • /
    • pp.83-97
    • /
    • 2023
  • The study aims to provide an academic basis for the preservation and restoration of abandoned paddy wetland and the enhancement of its carbon accumulation function. First, the temporal change of the wetlands was analysed, and a typological classification system for wetlands was attempted with the goal of carbon reduction. The types of wetland were classified based on three variables: hydrological environment, vegetation, and carbon accumulation, with a special attention on the function of carbon accumulation. The types of abandoned paddy wetlands were classified into 12 categories based on hydrologic variables- either high or low levels of water inflow potential-, vegetation variables with either dominance of aquatic plants or terrestrial plants, and three carbon accumulation variables including organic matter production, soil organic carbon accumulation, and decomposition. It was found that the development period of abandoned paddy analyzed with aerial photographs provided by the National Geographic Information Institute happened between 2010 and 2015. In the case of the wetland in Daejeon 1 (DJMN01) farming stopped by 1990 and it appeared to be a similar structure to natural wetlands after 2010 . Over the past 40 years the abandoned paddy wetland changed to a high proportion of forests and agricultural lands. As time went by, such forests and agricultural lands tended to decrease rapidly and the lands were covered by artificial grass and other types of forests.

A Study on the Spatial Therapy Program through the Analysis of the Meaning and Value of Old Houses : Focus on Kwon Seong-baek Old House in Andong (고택의 의미와 가치 분석을 통한 공간치료 프로그램 연구 : 안동 권성백 고택을 중심으로)

  • Jo, Jeong-Eun;Jang, Chang-Su;Kwon, Ki-Chang
    • 지역과문화
    • /
    • v.7 no.4
    • /
    • pp.49-68
    • /
    • 2020
  • The study of complementary medicine for the mental illness of modern people has been made up of academic fields. Psychotherapy, art therapy, literary therapy and dance therapy are among them, but these non-integrated studies are extremely limited to apply to reality. Collaboration with the medical community seeking supplementary measures after drug treatment is also a problem, and it is even more difficult to institutionalize them in a policy way. In response, the study suggested a shift to a space-oriented treatment paradigm by studying the value of space that most treatment programs value. Based on the theory of integrated literature therapy developed in Germany and introduced into Korea, the Tetra system was applied to one of Korea's cultural heritages. And I presented a sample of how to program the characteristics of the old house space. Kwon Seong-baek old house in Andong was considered a representative space and analyzed. As a similar case, we looked at the Healian Sun Village, the Knife Village in Germany, and the Temple Stay of Bongeunsa Temple to find out the actual conditions of space utilization. Accordingly, space treatment programs such as walking, writing poems, reading poems, and writing letters were presented by analyzing old houses with a Tetra system. This is significant as the first study to incorporate spatialization and placeability into the program.

Analysis of the Involving Mechanism of Kim Eun-Sook Drama : Focused on the Audience's Predictability and the Activities of Constructing Hypotheses (김은숙 드라마 <도깨비>의 몰입기제 구축과정 분석 - 관람자 예측성과 가설 구성 활동을 중심으로 -)

  • Kim, Eui-Jun
    • Journal of Korea Entertainment Industry Association
    • /
    • v.13 no.2
    • /
    • pp.79-91
    • /
    • 2019
  • In the entertainment industry, risk management is crucial for securing competitiveness due to the risk of investment. The competitiveness of contents is reinforced when external factors such as industrial environment and internal factors centering on involving mechanism are simultaneously provided. The involving mechanism is a form of cognitive response behavior of the audience and occurs through signal processing of the brain when watching the image contents. The signal processing of the brain related to the contents watching is mainly performed in the working memory area, and in the case of the captivating movie, the information other than the contents transmitted to the audience is blocked to generate a temporary dissociation state. A dissociation state similar to a symptom such as hypnosis or amnesia occurs when the audience's level of involving is high. On the other hand, contents information in which the audience is concentrating his attention is used intensively for constructing future thinking through an episodic buffer while the inflow of external information is relatively blocked or delayed. The spectator's future thinking configuration takes the form of a hypothesis-forming activity and is based on the predictability of the brain. When these hypothesized behaviors correspond to the problem solving simulation of story and predictability which is an evolutionary function of the brain, the audience' s brain is involved in the contents at a high level. In order for the act to be effective, the factors such as the background of the hypothesis, the subject of the hypothesis, the internal information of the person, the type and position and quantity of the hypothesis information, and the hypothesis relevance and type of information are important. Based on these factors, analysis of the Kim Eun Sook Drama 'Goblin' shows that the above elements are operated in a very organic and meaningful way.

Erodibility evaluation of sandy soils for sheet erosion on steep slopes (급경사면의 면상침식에 대한 사질토양의 침식성 평가)

  • Shin, Seung Sook;Park, Sang Deog;Hwang, Yoonhee
    • Journal of Korea Water Resources Association
    • /
    • v.55 no.4
    • /
    • pp.291-300
    • /
    • 2022
  • Artificial disturbance in mountainous areas increases the sensitivity to erosion by exposure of the subsoil with a low loam ratio to the surface. In this study, rainfall simulations were conducted to evaluate the erodibility of sand and loamy sand in the interrill erosion by the rainfall-induced sheet flow. The mean diameters of sand and loamy sand used in the experiment were 0.936 mm and 0.611 mm, respectively, and the organic matter content was 2.0% and 4.2%, respectively. In the experimental plot, the runoff coefficient of overland flow increased 1.16 times in loamy sand rather than sand. Mean sediment yields of loamy sand and sand by sheet erosion were 3.71kg/m2/hr and 1.13kg/m2/hr respectively. The erodibility, the rate of soil erosion for rainfall erosivity factor, was 3.65 times greater in loamy sand than in sand. As the gradient of the steep slope increased from 24° to 28°, the sediment concentration and the erodibility for two soils increased by about 20%. The erodibility factor K of sandy soils for small plots was overestimated compared to the measured erodibility. This means that RUSLE can overestimate the sediment yields by sheet erosion on sandy soils.

Counting Harmful Aquatic Organisms in Ballast Water through Image Processing (이미지처리를 통한 선박평형수 내 유해수중생물 개체수 측정)

  • Ha, Ji-Hun;Im, Hyo-Hyuk;Kim, Yong-Hyuk
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
    • /
    • v.6 no.3
    • /
    • pp.383-391
    • /
    • 2016
  • Ballast water provides stability and manoeuvrability to a ship. Foreign harmful aquatic organisms, which were transferred by ballast water, cause disturbing ecosystem. In order to minimize transference of foreign harmful aquatic organisms, IMO(International Maritime Organization) adopted the International Convention for the Control and Management of Ship's Ballast Water and Sediments in 2004. If the convention take effect, a port authority might need to check that ballast water is properly disposed of. In this paper, we propose a method of counting harmful aquatic organisms in ballast water thorough image processing. We extracted three samples from the ballast water that had been collected at Busan port in Korea. Then we made three grey-scale images from each sample as experimental data. We made a comparison between the proposed method and CellProfiler which is a well known cell-counting program based on image processing. Setting of CellProfiler is empirically chosen from the result of cell count by an expert. After finding a proper threshold for each image at which the result is similar to that of CellProfiler, we used the average value as the final threshold. Our experimental results showed that the proposed method is simple but about ten times faster than CellProfiler without loss of the output quality.

Analysis of Correoation between Water Quality Parameters in Goljicheon Basin (골지천 유역의 수질항목간 상관관계 분석)

  • Yu, Na Yeong;Shin, Min Hwan;Park, Bae Kyung;Kang, Tae Sung;Kim, Jong Gun
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2021.06a
    • /
    • pp.403-403
    • /
    • 2021
  • 비점오염물질은 강우에 의해 유출되며 계절적, 자연적 편차가 크게 나타나고, 오염원이 광범위하게 산재하고 있어 오염물질의 발생량과 부하량의 관리가 쉽지 않다. 따라서 비점오염원 관리지역은 오염물질이 하천에 미치는 수질 특성을 파악하는 것이 중요하다. 그러나 수질항목만으로 하천의 수질 특성을 파악하기에는 어려움이 있으며, 수질 특성을 파악하기 위해 다양한 분석방법이 필요하다. 본 연구에서는 비점오염원 관리지역 중 골지천 유역의 수질 특성을 파악하기 위해 통계분석 기법을 활용하여 수질항목간의 상관관계를 분석하고자 하였다. 2017년부터 2019년까지 골지천 유역 내 5개 지점에 대하여 비강우시 23회, 강우시 지점별 173회~196회의 모니터링 결과를 이용하였으며, EC, 탁도, BOD5, SS, T-N, T-P, TOC의 수질항목을 이용하여 Pearson 상관관계 분석을 실시하였다. 상관관계 분석 결과 비강우시 분석 결과 EC는 -0.06~-0.32, T-N은 0.19~0.37로 낮은 상관성을 갖는 것으로 나타났으며, EC와 T-N을 제외한 탁도와 BOD5, SS, T-P, TOC의 경우 서로 0.6 이상의 상관성을 갖는 것으로 나타났다. 특히, 탁도와 SS, T-P, T-P와 TOC는 0.9 이상의 높은 상관성을 갖는 것으로 나타났다. 강우시 분석 결과 EC는 비강우시와 유사하게 -0.07~-0.24로 낮은 상관성을 갖는 것으로 나타났으며, TOC를 제외한 탁도, BOD5, SS, T-N, T-P의 경우 서로 0.6 이상의 상관성을 갖는 것으로 나타났다. TOC의 경우 BOD5, SS와 0.6 이상의 상관성을 갖는 반면 탁도, T-N, T-P와는 0.45, 0.44, 0.57로 다른 항목에 비해 다소 낮은 상관성을 갖는 것으로 나타났다. 비강우시 T-N은 기저 유출에 의한 영향으로 높은 농도를 나타내 다른 항목에 비해 상관성이 낮은 것으로 나타났으며, 강우시에는 비점오염물질의 유입으로 인하여 모든 항목에서 비슷한 상관성을 보이는 것으로 나타났다. 본 연구 결과 탁도와 SS, T-P의 상관성이 비강우시 0.93, 강우시 0.78로 상당히 높은 것으로 나타나, 탁도를 측정하여 SS와 T-P로 환산하여 측정하는 방법에 대한 기초자료로 활용될 수 있을 것으로 판단된다. 그러나 연구 유역의 지형적 특성이 배제되었기 때문에 추후에 이를 반영한 연구가 필요할 것으로 판단된다.

  • PDF