• Title/Summary/Keyword: Water Quality

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A Study on Evaluation for the Han River Water Quality Index (한강의 수질지수 산정에 관한 연구)

  • 서정현
    • Water for future
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    • v.14 no.3
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    • pp.55-66
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    • 1981
  • The theory and practice of water quality scoring and indexing are introduced. The monthly water analysis data are available for six stations long the down-stream Han River whthin the areal boundary of the Special City of Seoul. The data cover the period between 1975 and 1979 inclusive and contain the analytical findings on 37 water constituents including DO, BOD, temperature, total solids and etc. Sic parameters are selected form the 37 items, that, to the judgement of the writer, best reflect the water quality of the Han River. They are; dissolved oxggen saturation, pH, fecal coliform, total solids, BOD and nitrate+ammonia. For each of the six parameters, a subscore function is developed and graphically presented to facilitate the transform of a measurment of the arameter to a subscore on a common score(e.G. 0-100) The score of a sample is calculated as a fuction of the six subscores, using four different approaches; (1) the unweighted arithmetic water quality score, (2) the weighted arithmetic water quality score, (3)the unweighted multiplicative score and (4) the reduced (total) score. Independent of these calculated scores, the experts' score which is calculated by averaging the ratings of water quality experts is obtained and compared with each of the four calculated scores by means of the least square method. The experts' score compares most favorably with the "reduced" score with the correlation coefficient of 0.956 : therefore this method of water quality scoring is adopted to calculate the Han River water quality scores and indices. Water quality index data for Guiri, ukdo, Pokwangdong, Noryangjin, Yongdungpo and Kayang Stations, 1975-1979 are as follow: The overall water quality index data of the Han River between Guiri and Kayang Stations are found; 47.3 in 1976, 48.0 in 1977, 48.5 in 1978 and 54.7 in 1979, indicating the general trend towards water quality improvent in this part of the river, in terms of the increased water quality index by average 1.85 points per year during this period. Finally the optimum sampling frequencies distributed among the six stations, using an equation which takes into account the coefficients of variation of the water quality scores and indices arec calculated.alculated.

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A Study on the Spatial Variation of Target Water Quality and Excess Rate at 41 Stations in Nakdong River Basin after the Total Maximum Daily Loads (수질오염총량제 시행 이후 낙동강수계 41개 지점의 BOD와 T-P의 목표수질과 초과율의 공간변화 분석)

  • Cho, Hyun kyung;Kwak, Eun Tae;Kim, Sang Min
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.6
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    • pp.97-109
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    • 2020
  • The objective of this study was to assess spatial variation of the target water quality criteria and excess rate in Nakdong river basin after the Total Maximum Daily Loads (TMDLs). For this, 41 total water quality monitoring stations were selected BOD and T-P data were collected from 2003 to 2019. The annual average water quality of BOD and T-P were calculated and compared with the target water quality for each stations by peroid. As a result of analyzing the BOD, Kumho A, Nakbon F, Namgang D, Miryang B, Wicheon B and Hoecheon A exceeded the target water quality criteria for two consecutive times. For T-P, Nakbon N, Naeseung B, Miryang A, Hwanggang A and Hoecheon A exceeded the target water quality criteria twice in a row. In the case of T-P, the target water quality excess rate was relatively low after the TMDLs implementation compared to before the TMDLs implementation. However, in the case of BOD, there was no difference in the target water quality excess rate before and after TMDLs. As a result, the overall annual average water quality shows a decreasing trend, but it is necessary to manage the water quality for the Nakdong river basin that exceed the target water quality.

Analysis of Water-Quality Constituents Variations before and after Weir Construction in South Han River using Probability Distribution (확률분포를 이용한 남한강 보 건설 전·후 수질변화 분석)

  • Kim, Kyung Sub
    • Journal of Korean Society on Water Environment
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    • v.35 no.1
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    • pp.55-63
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    • 2019
  • The Four Major Rivers Restoration Project started in 2009 and completed in early 2013 is a large-scale inter-ministry SOC project investing ₩22.2 $10^{12}$ and one of the Project's objectives was to enhance the water-quality grade through recovering the river eco-system and environment. The average concentration and probability distribution of water-quality constituents at given and selected sampling sites are very significant elements for analyzing and controlling the water-quality of rivers or reservoirs effectively. Average concentration can be estimated by point estimator, distribution function of water-quality constituents or Bootstrap method, in which the distribution function estimated with more data in case of insufficient dataset, is applied. Ipo and Gangcheon water-quality monitoring stations in South Han River were selected to compare and analyze the variation of concentration before and after Ipo and Gangcheon Weirs construction, using the whole 4-year's data, from 2005 to 2008 and from 2014 to 2017. Water-quality constituents such as BOD and COD relating to oxygen demanding wastes and TP and Chlorophyll-a relating to the process of nutrient enrichment called eutrophication were also selected. The guidelines for water-quality control and management after weir construction including evaluation of water-quality constituents' variations can be presented by this paper.

Status and its Improvement of Comprehensive Water Quality Evaluation (물환경 종합평가의 현황과 선진화 방안)

  • Choi, Ji Yong;Lee, Jee Hyun;Lee, Jae Kwan;Kim, Chang Su
    • Journal of Korean Society on Water Environment
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    • v.22 no.5
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    • pp.748-756
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    • 2006
  • Accurate and timely information on status and trends in the environment is necessary to shape sound water quality management policy and to implement water quality improvement programs efficiently. One of the most effective ways to communicate information on water quality trends to policy-makers, scientists, and the general public is with comprehensive water quality indices. The derivation and structure of a water quality index (WQI) for the classification of surface water quality is discussed. The WQI generally developed through the selection, transformation and weighting of determinants with rating curves based on legal standards and quality directives or guidelines. The representative pollutants should be included in the index, and the relationship between the quantity of these pollutants in the water and the resulting quality of the water should be based on scientific results. The WQI be simply and meaningfully formulated that nonscientifically trained users can easily become familiar with the framework of the system and use the output data to evaluate their own pollution problems.

Study on the Effects of In-streams by Discharging the Treated Sewage in Urban Stream (도시하천에서 하수처리수의 유지용수 이용에 따른 영향 평가 연구)

  • Bang Cheon-Hee;Park Jae-Roh;Kwon hyok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.5
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    • pp.75-86
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    • 2005
  • Recently since urbanization has brought about a dried stream and a worse water quality, Anyang city discharged the third treated sewage into the upper stream of Anyancheon and Hakuicheon. As the result, Hakuicheon had the water level and velocity enough for a living thing in the water to live in but water quality was worse than it had been. Therefore in case of meeting the water level and velocity of the second grade water-quality which living things in the water can live in, the discharge and water quality to secure in-stream flow must be at least 0.350 $m^3/s$ and $BOD_5\;3.2 mg/{\iota}$ respectively. In Anyancheon the water level was increased a little higher than it had been but the velocity was almost unchanged in comparison with it before. On the other hand the water quality was a little better than it had been. Therefore in case of meeting the water level and velocity of the third grade water-quality that people can do water-friendly activity, the discharge and water quality to secure in-stream flow must be at least 0.688 $m^3/s$ and $BOD_5\;4.8 mg/{\iota}$ respectively. The water-quality prediction on the suggested eight scenarios was simulated in all satisfying the third grade water-quality.

The Monitoring of Corrosive Water Quality in Water Distribution System by Corrosion Characteristics of Raw and Tap water (원·정수의 부식특성에 따른 상수관망에서의 부식성 수질 모니터링)

  • Bae, Seog-Moon;Kim, Do-Hwan;Son, Hee-Jong;Choi, Dong-Hoon;Kim, Ik-Sung;Kim, Kyung-A
    • Journal of Environmental Science International
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    • v.24 no.7
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    • pp.907-915
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    • 2015
  • The tap water is generally known to be corrosive in the pH range at 6.5 ~ 7.5. And the degree of corrosion varies depending on the types of raw water such as river surface water or lake water of the dam. Although several corrosion index represents the corrosivity of tap water, the typical corrosion indexes such as Langelier saturation index (LI) and calcium carbonate precipitation potential (CCPP) were calculated to monitoring the corrosive water quality about raw and tap water in water distribution system. To control the corrosive water quality, the correlation between corrosion index and water quality factors were examined. In this study, corrosion index (LI, CCPP) and the pH was found to be most highly correlated.

A Study on Water Quality Standard for the Protection of Human Health and Aquatic Life (인체의 위해성과 수생태계를 고려한 수질환경기준 설정에 관한 연구)

  • Lee, Jae-Hyun;Kim, Yoon-Shin
    • Journal of Korean Society on Water Environment
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    • v.23 no.6
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    • pp.985-992
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    • 2007
  • There are about 40,000 chemicals used in Korea and 300 new types of chemicals are added to the list every year, influencing quality of air, soil and water. Water quality standards that serve as the basis for water quality management have been proved inefficient and insufficient compared to those of advanced countries. This study aims to improve the existing water quality standards. Most importantly, the water quality standards need to take into account not only protection of human health but also aquatic resources. To that end, water quality criteria need to be set by monitoring each watershed every year and conducting risk assessment. Criteria for human health are set at $10^{-6}$ cancer risk level, and for aquatic life at conservative level, adopting the methodology of the U.S. and Australia, respectively. After carrying out technical and economic feasibility studies, more conservative criteria will be used to decide final water quality standards. The development of this system to establish integrated water quality standards for both human health and aquatic resources protection is urgently needed.

An Factor Analysis of Groundwater in Chongju City (청주시 지하수의 인자분석)

  • 남기창
    • Journal of environmental and Sanitary engineering
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    • v.18 no.4
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    • pp.6-14
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    • 2003
  • A spring water quality was depend on the aquifer soil status. However, water quality was rapidly contaminated by artificial affects. In the contaminate components, the heavy metals were significantly important because the heavy metals influence the plants and the animals. But, it is difficult to find out how the heavy metal can affect in the water quality. According to the group analysis and the factor analysis, water quality management was advanced. The experimental area was divided into three region and six factor. The six factor could not define the overall water quality, however this method were one of the useful methods.

Multivariate Analysis of Water Quality Data at 14 Stations in the Geum-River Watershed (금강유역 14개 관측점의 수질자료를 이용한 수질의 다변량분석)

  • 임창수
    • Journal of Environmental Science International
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    • v.8 no.3
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    • pp.331-336
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    • 1999
  • The monthly water quality data measured at 14 stations located in the Geum-River watershed were clustered into 2 to 7 clusters. Furthermore, factor analyses were conducted on Gabcheon and Yugucheon to characterize the water qualtiy, based on the information obtained from the results of culster analysis. The results of cluster analysis show that the water quality charactersitic of main stream of the Geum-River is somewhat different from that of substream of the Geum-River. Furthermore, the water quality characteristic of Gabcheon which is expected to have the most serious water quality problems in the Geum-River watershed shows the most different water quality characteristic from Yugucheon. Based ont he factor loadings in each factor, Gabcheon and Yugucheon have their own water quality characteristics. This is mainly because of composite factors such as different population density, industrial activities, and land use conditions in Gabcheon and Yugucheon subwatersheds.

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Contributions to the Impaired Water Bodies by Hydrologic Conditions for the Management of Total Maximum Daily Loads (수질오염총량관리 목표수질 초과지역에 대한 유황별 초과기여도 분석)

  • Park, Jun Dae;Oh, Seung Young
    • Journal of Korean Society on Water Environment
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    • v.28 no.4
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    • pp.574-581
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    • 2012
  • It is important to analyze the status of water quality with relation to the stream flow to attain water quality goal more effectively in the unit watersheds for the management of Total Maximum Daily Loads (TMDLs). This study developed a flow duration-water quality distribution graph to figure out water quality appearances on the flow variation and analyzed contributions of water quality observations to the impaired water bodies quantitatively by hydrologic conditions. Factors relating to water quality variation can be analyzed more precisely and assessed on the base of quantified contributions. It is considered that this approach could be utilized to establish a more effective plan for the water quality improvement including the prioritization of pollution reduction options.