• Title/Summary/Keyword: River Min

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Verification of Water Environment Network Representative at the Baekcheon Junction of the Nakdong River (낙동강 백천 합류부 지점의 물환경측정망 대표성 검증)

  • Ahn, Jung Min;Im, Teo Hyo;Kim, Sung Min;Kim, Shin;Kim, Gyeong Hoon;Kwon, Heon Gak;Shin, Dongseok;Yang, Deuk Seok
    • Journal of Environmental Science International
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    • v.27 no.6
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    • pp.371-381
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    • 2018
  • Multifunctional weirs constructed through the Four Major Rivers Restoration Project are operated as management water levels. The purpose of this study was to evaluate the effect of water level in the main stem on the tributary water level according to multifunctional weir operation, because the operation of multifunctional weirs for water level management influences the drainage of tributaries. In this study, water level pressure gauges were installed and spatial and temporal water quality was observed. The LOcally Weighted Scatterplot Smoothing (LOWESS) technique was applied to the Nakdong River and the Baekcheon Junction, both upstream of the Gangjeong-Goryeong weir, in order to analyze water quality trends. When considering the overall analysis and observations, it was found that the water quality forecasting point located at the Baekcheon estuary point should be transferred to the Dosung Bridge, which is located upstream of the Sunwon Bridge.

Development and Application of the Grid-Distributed Model for Contribution Rate Analysis on Non-point Source Pollution According to Landuse (토지피복별 비점부하량 기여율 해석을 위한 분포형 모델 개발 및 적용)

  • Ahn, Jung-Min;Jung, Kang-Young;Kim, Shin;Lee, Hae-Jin;Shin, Suk-Ho;Yang, Duk-Seok;Shin, Dongseok;Na, Seung-Min
    • Journal of Korean Society on Water Environment
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    • v.33 no.1
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    • pp.78-89
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    • 2017
  • Water quality monitoring network data is being affected continuously due to non-point source pollution arising from agricultural land located on the Gwangsancheon outlet in the Nakdong River basin. In this study, we have performed analysis of water quality monitoring system, water quality pattern using SOM and water quality in the Gwangsancheon for sub-basin located at Gisan-myeon in the Nakdong River basin. We have developed and applied the model to estimate the runoff and non-point source loading. As a result of SOM pattern, the effect of non-point source pollution was the largest in the paddy fields and fields. As a result of the developed model, we found contribution rate and reduction rate for non-point source loading according to change of landuse because the reduction effect of nonpoint pollutants was 20.9% of SS, 9.9% of TN, 21.2% of TP and 8.9% of TOC depending on the landuse change.

Impacts of dam discharge on river environments and phytoplankton communities in a regulated river system, the lower Han River of South Korea

  • Jung, Seung Won;Kwon, Oh Youn;Yun, Suk Min;Joo, Hyoung Min;Kang, Jung-Hoon;Lee, Jin Hwan
    • Journal of Ecology and Environment
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    • v.37 no.1
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    • pp.1-11
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    • 2014
  • To understand the effects of fluctuations in dam discharge due to river environments and phytoplankton communities, we monitored such environments and phytoplankton communities biweekly, from February 2001 to February 2002 and from February 2004 to February 2005, in the lower Han River (LHR), South Korea. The phytoplankton abundance during the dry season was approximately two times higher than that during the rainy season. In particular, fluctuations in diatom assemblages, which constituted over 70% of the total phytoplankton abundance, were affected severely by the changes in the discharge. When a large quantity of water in a dam was discharged into the LHR, the conductivity and the concentrations of total nitrogen (TN), total phosphorus (TP), and dissolved inorganic phosphorus (DIP) decreased rapidly, whereas the concentrations of suspended solids (SS), dissolved inorganic nitrogen (DIN), and dissolved silica (DSi) increased immediately. Time-delayed relationship also revealed that the dam discharge had an immediately significant negative relationship with phytoplankton abundance. On the whole, fluctuations in phytoplankton communities in the LHR were influenced much more by hydrodynamics such as dam discharge than by the availability of nutrients. Thus, the variability in these concentrations usually parallels the strength of river flow that is associated with summer rainfall, with higher values during periods of high river discharge.