• Title/Summary/Keyword: Ecological assessment

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Water Quality Modeling and Response Assessment in the Yellow Sea and the East China Sea (황해 및 동중국해의 수질예측과 응답성 평가)

  • Lee, Dae-In
    • Journal of Environmental Impact Assessment
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    • v.21 no.3
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    • pp.445-460
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    • 2012
  • In order to evaluate and predict the environmental impact of the low-trophic-level ecosystem to environmental changes in the Yellow Sea and the East China Sea, an ecological modelling study was undertaken. Simulation results of average distribution patterns and concentrations of water quality factors during the summer by the model were acceptable. Phytoplankton and remineralization rate of organic matter were very important parameters by a sensitivity analysis. Water quality factors showed high values in the estuary of the Yangtze River and in the West and South Sea of Korea and low values in the central area of the Yellow Sea. There is a plume of high values, especially nutrients, off the mouth of the Yangtze that expands or contracts with changes in the discharge strength. Characteristics of responses of water quality factors vary for different scenarios of environmental change, such as land-based pollution sources and atmospheric forcing. It is suggested that changes of light intensity, discharges of input sources, and wind play an important role in the marine ecosystem.

Review on the Conservation Value and Assessment Criteria of Vegetation (식생의 보전가치와 평가기준에 대한 검토)

  • Choung, Heung-Lak;Song, Jong-Suk;Lee, Kyu Song;Kim, In-Taek;Kim, Jong-Hong;Yang, Keum-Chul;Chun, Young-Moon
    • Journal of Environmental Impact Assessment
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    • v.15 no.5
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    • pp.339-355
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    • 2006
  • In this paper, we reviewed the assessment criteria and conservation value used to evaluate vegetation. The Degree of Green Naturality (DGN) and the Grade of Vegetation Conservation (GVC) are both sets of criteria that estimate the degree of human disturbance or natural value of vegetation. The criteria are extensively used in decision-making about the natural environment conservation and environment impact assessment. Sometimes, social issues can rise because the criteria are not clear. This study aims to evaluate the criteria based on the many aspects of the related literatures and suggest reasonable revised criteria. In addition, criteria for representing the relative value of valuable vegetation conservation are suggested. The DGN and GVC are essentially same; both have 11 degrees and 5 grades. While the DGN is subdivided into levels of anthropogenic disturbances, the GVC indicates the priority for conserving valuable vegetation. Therefore, the DGN is very useful for assessing land development projects, etc., while the GVC is needed to delineate the Ecological Assessment Map(EAM). In conclusion, it is desirable that both criteria should be used together appropriately.

Characterizing Ecological Exergy as an Ecosystem Indicator in Streams Using a Self-Organizing Map

  • Bae, Mi-Jung;Park, Young-Seuk
    • Korean Journal of Environmental Biology
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    • v.26 no.3
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    • pp.203-213
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    • 2008
  • Benthic macro invertebrate communities were collected at six different sampling sites in the Musucheon stream in Korea from July 2006 to July 2007, and ecological exergy values were calculated based on five different functional feeding groups (collector-gatherer, collector-filterer, predator, scrapper, and shredder) of benthic macro invertebrates. Each sampling site was categorized to three stream types (perennial, intermittent and drought) based on the water flow condition. Exergy values were low at all study sites right after a heavy rain and relatively higher in the perennial stream type than in the intermittent or the drought stream type. Self-Organizing Map (SOM), unsupervised artificial neural network, was implemented to pattern spatial and temporal dynamics of ecological exergy of the study sites. SOM classified samples into four clusters. The classification reflected the effects of floods and droughts on benthic macroinvertebrate communities, and was mainly related with the stream types of the sampling sites. Exergy values of each functional feeding group also responded differently according to the different stream types. Finally, the results showed that exergy is an effective ecological indicator, and patterning changes of exergy using SOM is an effective way to evaluate target ecosystems.

Basic Research on Mid-to-Long-term Management Plan of Purchased Land by Evaluating Ecological Function of Waterfront Area of Geum River (금강수계 수변구역의 생태 기능 평가를 통한 매수토지 중장기 관리 방안 기초 연구)

  • Seo, Jung-young
    • Journal of Environmental Science International
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    • v.28 no.3
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    • pp.371-384
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    • 2019
  • The purpose of this study was to propose an efficient management plan for purchased land considering the hydrological, watershed characteristics and ecological functions of the target land and surrounding area based on the result of monitoring the water quality improvement effect obtained by purchasing the land in the watershed area in the Geum river system. For this purpose, this study investigated through literature review, and examined ways to apply them to this research by deriving implications from a comprehensive analysis of previous research cases. After that, the components of assessment were derived to evaluate the ecological function of the purchase land, and the ecological function evaluation model for each land and area was proposed. In order to select purchase and restoration priorities of the land, this study analyzed the ecological status of the purchased land in main watersheds and tributaries using Arc GIS ver 10.1. Through this, a process to select restoration priorities was developed. And this study constructed the integrated management process with proposing a mid - to long - term plan by integrating the purchased land valuation and restoration priority selection process. Based on this process, this study suggested an effective management plan for purchased land through the integrated ecological management system of lands purchased. It can be used systematically in appraisal valuation, land purchase system, restoration project, and follow-up management of land purchase.

Toxic effect of chlorothalonil, an antifouling agent, on survival and population growth rate of a marine rotifer, Brachionus plicatilis (해산 로티퍼(Brachionus plicatilis)의 생존율 및 개체군 성장률을 이용한 신방오물질(Chlorothalonil)의 독성영향)

  • Heo, Seung;Lee, Ju-Wook;Choi, Hoon;Yoon, Sung-Jin;Kwon, Ki-Young;Hwang, Un-Ki;Park, Yun-Ho
    • Korean Journal of Environmental Biology
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    • v.39 no.3
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    • pp.390-398
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    • 2021
  • In this study, the toxicity of chlorothalonil was investigated using survival rate and population growth rate of a marine rotifer, Brachionus plicatilis, typically used in live food in marine aquaculture systems. The survival rate of B. plicatilis was determined after 24 h of exposure to chlorothalonil (0.010-0.156 mg L-1). Population growth rate of B. plicatilis was calculated after 72 h of exposure to chlorothalonil (0.078-1.250 mg L-1). The survival rate and population growth rate of B. plicatilis exposed to chlorothalonil in single-dose toxicity assessment showed concentration-dependent reductions. Survival rates of B. plicatilis exposed to chlorothalonil had the following values: NOEC, 0.020mg L-1; LOEC, 0.039 mg L-1; and EC50, 0.057 mg L-1. Population growth rate of B. plicatilis exposed to chlorothalonil had the following values: NOEC, 0.156 mg L-1; LOEC, 0.313 mg L-1; and EC50, 0.506 mg L-1. When the residual concentration of chlorothalonil in the marine coastal area was more than 0.039 mg L-1, it had a toxic effect on B. plicatilis, a zooplankton. This paper provides toxicity values that can be used as baseline data for organizing environmental standards of chlorothalonil. It also provides insight into toxic effects of chlorothalonil on other non-target organisms.

Speciation and Ecological Risk Assessment of Trace Metals in Surface Sediments of the Masan Bay (마산만 표층퇴적물에서 미량금속의 화학적 존재형태 및 생태계 위해도 평가)

  • Sun, Chul-In;Lee, Young-Ju;An, Jung-Hyun;Lee, Yong-Woo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.19 no.2
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    • pp.155-163
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    • 2014
  • Total concentration and chemical speciation of trace metals (Cu, Pb, Zn, Cd, and Ni) were determined to evaluate pollution level and potential ecological risk in surface sediments of the Masan Bay. The results showed that the trace metal concentrations, except for Ni, were high in the inner Masan Bay. Based on the chemical speciation of metals in sediments, the percentage of total concentrations of Cd and Pb in non-residual fraction was 92% and 88%, respectively, indicating that these metals originated mainly from anthropogenic sources. However, Ni (70%) was dominant in residual fraction. Pollution load index (PLI) and ecological risk index (ERI) values in the inner bay indicate the presence of anthropogenic pollution and considerable-moderate ecological risk, respectively. Ecological index (Ei) value for Cd was high at most stations in the Masan Bay, and Cd content was the highest in acid soluble fraction, which presents the highest ecological risk. The results obtained in this study indicate that Cd presents a high potential ecological risk to benthic biota in the Masan Bay.