• Title, Summary, Keyword: diatom analysis

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Quantitative Reconstruction of Sea Level Change Using Diatom-Based Transfer Function at Sinduk-ri, Gochang-Gun Since the Middle Holocene (규조기반 전이함수를 활용한 Holocene 중기 이후 고창군 신덕리 일대의 정량적 해수면 변동)

  • Kim, Jeong-Yun;Yoon, Soon-Ock;Yang, Dong Yoon;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.3
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    • pp.13-25
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    • 2017
  • This study is quantitative reconstruction of palaeo sea level records around Sinduk-ri, Gochang-Gun. 7 cores were collected from GC14 to GC18 in order to examine the entire sedimentary facies and reconstruct the sea level records. The cores were analysed by AMS, sedimentary facies, diatom and WA-pls. As a result of the diatom analysis, diatom zone were classified as No diatom zone, B1 zone, M zone and B2 zone. The result of WA-pls was that the sea level was about 1.5m lower than the present level around 6,000 BP and about 1m lower during last 5,000 BP. Thereafter, sea level rose to the present during the Mc sub-diatom zone period. Moreover, during the Md sub-diatom zone period, sea level was about 0.5m higher than the present.

Studies on Morpho-pedo Milieu of Forest Wetland on Mt. Jeombong - Focused on Diatom Analysis and Grain Size Analysis (점봉산 산림습지의 지형·토양 환경분석 - 입도분석과 규조분석을 중심으로)

  • Kim, Nam-Shin;Cha, Jin-Yeol;Park, Yong-Su;Cho, Yong-Chan;Kwon, Hye-Jin;Oh, Seung-Hwan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.1
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    • pp.13-24
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    • 2017
  • This study is to provide basic data on ecology and morpho-pedo milieu by analyzing diatom and grain size of Mt. Jeombong forest wetland. Sample was collected from 6 points and named sample 943, 932, 885, 881A, 881b, 849. Sample 934 could not identify diatom, and the soil layer was colluvium deposited by mass-movement process. Layer of sample 932 was developed in the lower velocity environment, and presence frequence of complete diatom was very low. Hydrological situation of sample 855 was analysed in oligosaprobien environments. Sample 881A was meso-saprobic environments, velocity was slow area that inhabit musci bryopsida and sphaerocarpus. Sample 881B was acidic wetland in oligosaprobien environments. Sample 849 was analysed in oligosaprobien environments. The results of soil and diatom analysis are well reflect on wet environments of mountain wetlands and also it will expected to be in the help of environmental changes study of mountain wetlands.

Study of the Correlation Between Diatom and Environmental Variables for Palao-Sealevel Reconstruction in the Korea Peninsula: Case Study of the Eastern Tidal Flat of Gomso Bay (한반도 고해수면 변동 복원을 위한 규조-환경변수 상관관계 연구: 곰소만 동부 조간대 지역을 대상으로)

  • Kim, Jeong-Yun;Yoon, Soon-Ock;Yang, Dong Yoon;Hwang, Sang ill
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.2
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    • pp.79-90
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    • 2017
  • This study investigated the correlation between the diatom community and the environmental variables on the tidal flat surface of the eastern part of Gomso Bay in the West coast of Korea in order to utilize the quantitative sea level record as a basic data. 24 sediment samples at 10cm intervals downstream of the Galgok Stream were used for diatom analysis, grain size analysis and CCA. As a result of diatom analysis, marine diatoms dominated at lower altitudes and the ratio of diatoms to fresh water diatoms and brackish diatoms increased toward upland. As a result of CCA, the contribution of environmental variables was analyzed as 25.3% at altitude, 21.6% at sand, 13.3% at skewness, etc. This means that altitude above sea level has the greatest influence on the diatom composition in the tidal flat surface. It suggests that the contribution of environmental variables at altitude above sea level can be used as a basic data for the quantitative records for reconstruction of paleo-sea level.

Dynamics of Epilithic Diatom Communities and Biological Water Quality Assessment in Geum River and Downstream Yongdam (금강과 용담댐 하류하천 부착규조 군집 동태 및 생물학적 수질 평가)

  • Park, Yeon-Jeong;Kim, Han-Soon;Ban, Yang-Jin;Lee, Hee-Suk
    • Journal of The Korea Society For Environmental Analysis
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    • v.20 no.3
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    • pp.138-144
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    • 2017
  • This study was conducted to investigate the water quality of the Geum River and downstream Yongdam using Diatom Assemblage Index to organic water pollution (DAIpo) and Trophic Diatom Index (TDI). Water quality parameters, such as Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Total Phosphorus (TP), were analyzed. A total of 99 diatom taxa belonging 27 genera and 75 diatom taxa belonging 25 genera were identified in the epilithic diatom communities of Geum River and downstream Yongdam, respectively. In Geum River, the dominant species were indifferent and saprophilous taxa, such as Achnanthes minutissima, Fragilaria crotonensis, Nitzschia inconspicua, Nitzschia palea, and Cyclotella atomus. However, the dominant species were in indifferent and saproxenous taxa, such as Achnanthes minutissima, Cocconeis placentula var. lineata, and Reimeria sinuata in downstream Yongdam. The mean biological indices (DAIpo and TDI) indicated poor water quality in Geum River but good water quality in downstream Yongdam.

A Note on Biogenic Effects of Coralloid Speleothems in Round Mountain Lava Cave, Oregon, U.S.A.

  • Kashima, Naruhiko;Ogawa, Takanori
    • Journal of the speleological society of Korea
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    • v.9
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    • pp.3-7
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    • 1999
  • Corralloid speleothems from Round Mountain lave cave are are studied by scanning microscope and electron microprobe analyses. Scanning microscopy observation indicates that the diatom Melosira seems to contribute significantly to siliceous coralloid speleothems Electron microprobe confirms the presence of diatom and fragmental minerals(plagioclase and orthopyroxene) in coralloid speleothems. Chemical analysis of 3 diatom cells gives SiO2(74.8%), Al2O3(0.12%), FeO(0.11%), CaO(0.47%) and MgO(0.81%).

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Distribution of Epilithic Diatom Communities in Relation to Land-Use and Water Quality in the Geum River System, South Korea (금강수계의 토지이용 및 수질구배에 따른 돌부착 돌말류의 분포특성)

  • Cho, In-Hwan;Hwang, Soon-Jin;Kim, Baik-Ho;Kim, Yong-Jae
    • Journal of Korean Society on Water Environment
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    • v.30 no.3
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    • pp.283-291
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    • 2014
  • To study the distribution characteristics of diatom communities in relation to the gradient of water quality and land-use, water samples and epilithic diatoms were collected from 90 sites including mainstream and tributaries, in the Geum River System (GRS) during no rainfall, May 2011. Of 239 taxa identified, Achnanthes convergens and Cymbella minuta were dominated over all the sites. Cluster analysis on the GRS divided into three groups. Group 1 (G1) is the mountainous upstream, a relatively good water quality, and mainly consisted of saproxenous species. Group 2 (G2) is the urban sites, polluted (high in electric conductivity, total phosphate and soluble reactive phosphorus), and saproxenous and common species. Group 3 (G3) is the agriculture sites, and polluted (turbidity, total nitrogen, nitrate), and saprophilous species. There were some discrepancies between abiotic and biotic variables in GRS; biologically similar between G1 and G2, but abiotically similar between G2 and G3. These differences may attribute to not only physiological characteristics of diatom cells, but complicate relationships between microhabitat and water quality. Thus, an urgent development of generalized or standardized methods to diminish the differences between epilithic diatom community and environments is advent.

Assessment of Water Quality in the Sum-river and the Dal-stream using Epilithic Diatom-based Indices (부착규조류를 이용한 달천과 섬강의 생물학적 수질평가)

  • Kim, Yong-jin;Lee, Ok-min
    • Journal of Korean Society on Water Environment
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    • v.25 no.4
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    • pp.606-614
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    • 2009
  • To evaluate the biological water quality, diatom-based biological indices (DAIpo and TDI) were examined in the Sum-River and the Dal-stream. Having BOD concentrations below $2mg{\cdot}L^{-1}$ in most sites, water quality of both rivers was good. The DAIpo and TDI values ranged from 29.8 to 91.4 and from 38.7 to 93.0 respectively. From the biological water quality assessment, DAIpo and TDI for both rivers displayed fair to fairly poor water quality levels. However, the two indices showed more polluted conditions than expected from the BOD vlaues. In addition, DAIpo, having wider range of differences, appears to be more sensitive to the change in water quality when compared to TDI values. Statistical analysis using principal component analysis showed that Nitzschia palea and Diatoma vulgare might not be the appropriate indicators due to their low correlations with other indicators.

Diatom Succession Representing the Paleoclimatic Change from Laminated Sediments around Antarctica (남극 엽층리 퇴적물로부터 규조 종을 이용한 고기후 변화 연구)

  • Bak, Young-Suk;Yoon, Ho Il;Yoo, Kyu-Cheul;Lee, Young-Up
    • Journal of the Korean earth science society
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    • v.36 no.2
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    • pp.190-197
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    • 2015
  • This study investigated the paleoclimatic change using diatoms that were extracted from the high-resolution laminated layers of diatom ooze sediment cores GC08-EB01 in the eastern basin of the Bransfield Strait, Antarctica. The range of diatom valves per gram of dry sediment was from $0.4-4.2{\times}10^8g^{-1}$ in quantitative diatom assemblage analysis. Laminations are classified using visually dominant diatom species and terrigenous content. Biogenic diatom ooze laminae characterised by bloom of Corethron crilophilum, Eucampia antarctica, Fragilariopsis curta, F. kerguelensis, Odontella weissflogii, Proboscia inermis, R. styliformis, Thalassiosira antarctica, and Chaetoceros resting spores. Terrigenous laminae characterised by mixed diatom assemblage. The ratio of (Fragilariopsis curta+F. cylindrus)/Thalassiosira antarctica increase in horizons, suggesting increased sea-ice cover in the study area during the late Holocene (cold events). As a result, five cold events are identified on the basis of frequency of the critical taxa throughout the section.

Assessment of Ecological Streamflow for Maintaining Good Ecological Water Environment (수생태 환경유지를 위한 하천생태유량 산정)

  • Jung, Chung-Gil;Lee, Ji-Wan;Ahn, So-Ra;Hwang, Soon-Jin;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.3
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    • pp.1-12
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    • 2016
  • The objective of this study is to analyze the relationship between stream water quality of TN (total nitrogen), TP (total phosphorus), and BOD (Biochemical Oxygen Demand) and TDI (Trophic Diatom Index) score determined by physico-chemical factors, biomass, and standing crops of epilithic diatoms, and to estimate the required amount of ecological streamflow for good water environment of Trophic Diatom. For the main stream of Chungju dam watershed of South Korea, total 100 field data of 3 years (2008~2010) measured in May and September were used to derive the relationship between water quality and TDI. Trophic Diatom had high correlation (0.55 determination coefficient) with TN. Using the relationship, the required streamflow was evaluated by using the Soil Water Assessment Tool (SWAT) for good Trophic Diatom water environment through T-N water quality maintenance. The SWAT simulated 8 years (2003~2010) stream discharges and T-N water quality along the main stream. From present garde C (score range: 30.0~45.0) to grade A (score above 60.0) of TDI, the May needs additional streamflow of $63.1m^3/sec$ (+36.7 % comparing with the present streamflow of $172.0m^3/sec$) at the watershed outlet.

Assessment of Seasonal Algae Variability in a Reservoir

  • Lee, Ju Young;Han, Mooyoung;Kim, Tschungil
    • Environmental Engineering Research
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    • v.19 no.3
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    • pp.223-228
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    • 2014
  • We investigated seasonal algae variability and its influence on water quality in an agricultural reservoir. We observed that maximal total phosphorus (TP) loads were 1,715 kg from farmland in September, which changed the ecosystem in the reservoir. At this time, Dictyosphaerium pulchellum as green algae dominated. Aulacoseira ambigua as diatom became the most dominant from November 2010 to May 2011. The diatom was sensitive to water temperature. Microcystis spp. and Oscillatoria spp. as cyanobacteria were dominant during summer and fall, and sank down to the sediment during winter and spring. Increasing water temperature during summer causes anaerobic conditions in the sediment, leading to regrowth of cyanobacteria. With regard to the ratio of total nitrogen (TN) to TP, green algae and cyanobacteria were dominant at TN:TP ratios less than 20-30. Diatoms were dominant at TN:TP ratios greater than 30-40. Statistical analysis indicated that diatom growth was dependent on water temperature and TN concentration. TP concentration and water temperature were the key factors for the growth of cyanobacteria and green algae. From these results of this study, the management of land-use was an important parameter for improving water quality in the agricultural reservoir.