• 한국습지학회지
• /
• 제19권3호
• /
• pp.311-317
• /
• 2017

본 연구에서는 낙동강수계에서의 수질 모니터링 자료를 이용하여 수질지수를 산정하고 생활환경기준과 비교를 통해 수질상태를 검토하였다. 수질지수는 환경부에서 현재 시행되고 있는 실시간수질지수(RWQI) 방법인 CCME-WQI을 사용하였으며 수질항목은 pH, DO, EC, 수온, TOC, T-N, T-P에 대해 7개 평가항목으로 선정하였다. 평가기간은 최근 3년간(2013년~2015년)으로 선정하였으며 해당 기간 내 측정된 수질 모니터링 자료를 이용하였다. 평가결과, 전 기간 평가 결과는 지수와 생활환경기준이 비슷한 경향을 보이나 월별 평가는 지수와 BOD, T-P 결과가 다르게 나타났다. 따라서 효율적인 하천관리를 위해서는 단일 수질항목만의 평가보다 복합적인 평가가 보다 필요할 것으로 신뢰성이 있는 것으로 검토되었다.

• 상하수도학회지
• /
• 제25권5호
• /
• pp.707-717
• /
• 2011

Replacement of old water distribution pipes for protecting water quality induced by pipe corrosion requires enormous budget. Even after the replacement, however, corrosion can occur again at any times and, therefore, inhibitive measure of the corrosion will be not only economical but needed to diminish the consumers' distrust on tap water quality. In 2008, National Environmental Research Institute did a survey on 8 major drinking water source and proposed to establish the Langelier Saturation Index(LI) as a corrosion index in Drinking Water Quality Criteria. Among the water industries of Korea, K-Water is the only one that set up the level of pH over 7.0 and LI above -1.5 on yearly average basis. However, no systematic regulation including LI to inhibit the corrosive tendency has been established yet. In this paper, LI values out of 31 drinking water treatment plants were analyzed and two-stage control of LI value as a measure of corrosive tendency of water is proposed. Primarily, water treatment facilities may operate the system at a target LI value below -1.5. Following the investigation on the effect caused by adjusting the LI value on water quality and corrosiveness, it will be desirable to improve LI value below -1.0 in the long run. In addition to the LI, supplemental use of Larson's modified ratio (LMR) which incorporates hydraulic detention time will be necessary. Several methods to prove the inhibitive effect of improving the LI value on water quality have been also suggested.

• 한국물환경학회지
• /
• 제22권5호
• /
• pp.748-756
• /
• 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.

• 한국물환경학회지
• /
• 제28권1호
• /
• pp.78-83
• /
• 2012

Man-made reservoirs over 95% in Korea are shallower than 10 meters in depth, which is apt to cause eutrophication. This study has characterized long-term trends in water quality factors for the selected six reservoir points in the Kum River watersheds, and then estimated the seasonal trophic state index for each reservoir. The reservoir trophic state was evaluated at four trophic levels using the Korean trophic state index, TSIKO. It is observed from seasonal results for six reservoirs that the highest value of the trophic state index is estimated in summer while the trophic state index value is low in spring and winter seasons. Especially, the Boryeong Lake has a relatively lower trophic state index since this reservoir has been managed properly for water withdrawal and irrigation. It is expected that the seasonal trophic state index resulted from this study can contribute toward long-term water quality improvement plans for reservoirs.

• 물과 미래
• /
• 제14권3호
• /
• pp.55-66
• /
• 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.

• 한국물환경학회지
• /
• 제39권4호
• /
• pp.261-268
• /
• 2023

The benthic macroinvertebrates index (BMI) was developed based on the 5-day biochemical oxygen demand (BOD₅), which is the amount of biodegradable organic matter in stream water. However, benthic macroinvertebrates mainly live in the streambed substrate and are affected by the interaction of water quality and substrate. This study was conducted to examine the interactive relationship between water quality items (BOD₅, total phosphorus (TP), total suspended solids (TSS)) and substrate with BMI by performing statistical analyses (four-way analysis of variance, Pearson's correlation analysis, partial correlation analysis and multiple regression analysis). The data used in the analyses were collected from 19,915 sampling units at 1,937 sites in South Korea from 2010 to 2020. The interaction effect between BOD₅ and substrate types was confirmed through a four-way analysis of variance. Partial correlation analysis and multiple regression analysis estimated the degree of influence on the change in BMI value in the order of mean grain size of the substrate as (𝜱_m) > BOD₅ > TP > TSS. BMI can be regarded as an index that evaluates the comprehensive effects of water quality and streambed status, although it is an index that was developed based on the amount of biodegradable organic matter in a water column.

• 대한토목학회논문집
• /
• 제34권5호
• /
• pp.1395-1408
• /
• 2014

본 연구에서는 시민들이 하천에서 안전하고 쾌적하게 레크리에이션 활동을 할 수 있도록 종합 수질 정보를 제공하는 하천 레크리에이션 지수 산정 모델을 개발하였다. 하천 레크리에이션 지수 모델은 분변성 대장균 모델과 수질지수 모델을 통합하여 구성하였다. 분변성 대장균 모델에서는 로지스틱 회귀분석을 사용하여 분변성 대장균 등급을 예측하였고, 수질지수 모델에서는 DO, pH, 탁도, 클로로필 a를 퍼지 합성방법을 통해 종합화하여 수질 지수를 산정하였다. 최종 단계에서 분변성 대장균 등급과 수질 지수를 통합하여 하천 레크리에이션 지수를 산정할 수 있도록 모델을 개발하였다. 제안된 모델을 낙동강의 강정고령보 상류 지점에 적용한 결과, 하천 레크리에이션 지수는 개별 수질인자들의 변화를 잘 반영하는 것으로 나타났다. 특히 하천 레크리에이션 지수와 클로로필 a의 상관계수가 -0.85로 나타나 클로로필 a가 하천 레크리에이션 지수에 가장 많은 영향을 미치고 있음을 확인할 수 있었다. 본 모델에서 산정한 종합수질지수는 기존 수질 정보 제공 시스템인 실시간 수질지수보다 보수적인 결과를 보였는데, 이는 등급에 따라 현재의 수질 상태가 어떠한 상태에 속하는지를 계산하고 수질 기준의 불확실성을 적절하게 고려하기 때문인 것으로 판단되었다. 나아가서, 분변성 대장균 등급이 낮을 경우 하천 레크리에이션 지수가 분변성 대장균을 고려하지 않고 있는 실시간 수질지수보다 낮은 결과를 제시하는 것으로 나타났다.

• 한국물환경학회지
• /
• 제26권5호
• /
• pp.796-801
• /
• 2010

Water quality index (WQI) can be a great tool that allows experts to translate large amount of complex water quality data into a format more easily understood by the public and policy makers. Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) can be calculated with the three factors (Scope: $F_1$, Frequency: $F_2$, Amplitude: $F_3$). After all, the WQI for a specific site is produced as a number between 0 to 100; the scale is also divided into five categories, i.e., Excellent, Good, Fair, Marginal and Poor. The WQI was found to be highly related to Chl-a, pH, temperature among the collected items. When the more input parameters were used, the range of variation generally became smaller. $F_3$ among the factors of WQI was influenced by algae. It showed a similar variation tendency between WQI and algal bloom in 2008.

• 환경영향평가
• /
• 제30권2호
• /
• pp.75-88
• /
• 2021

본 연구에서는 금강 수계의 자동측정망 중 6개 지점을 선정하고, 이와 동일하거나 인근에 위치해 있는 수질측정망 지점을 대상으로 두 지점의 수질특성 파악하고 통계 분석을 통하여 상관성을 평가하였다. 또한, 수질 분석결과를 활용하여 수질 지수로 변환하고 등급으로 표현해 비교하였다. 연구에 필요한 자료는 최근 4년간(2016-2019)의 국가물환경측정망 데이터를 활용하였으며 수온, pH, EC, DO, TOC, TN, TP를 평가항목으로 선정하였다. 수질 분석 결과, 자동측정망과 수질측정망의 수질농도는 일부 측정값의 차이는 보였지만 대부분 지점에서 일정한 비로 변동하는 경향을 보였다. 항목 간 상관분석결과 수온, EC, DO 항목은 측정망간 상관성이 매우 높았고, TOC, TN, TP 항목은 기본항목에 비해 낮은 상관성을 보였으나 일부 측정망을 제외하고 0.7 이상(상관계수 r)의 높은 상관관계를 나타냈다. 수질 지수 분석결과 자동측정망 수질지수와 수질측정망 수질지수가 비슷한 경향을 보이는 것으로 평가되었으며, 두 결과 모두 하류로 갈수록 지수점수는 낮아져 오염도가 증가되고 있음을 쉽게 파악할 수 있었다.

• Environmental Engineering Research
• /
• 제23권2호
• /
• pp.150-158
• /
• 2018

The deteriorating role of Nakdong River due to the Four Major Rivers Project has caused a series of problems, including water pollution, drying streams, aggravation of the hydroecology. Geumho River and Gyeongseong-cheon had a higher concentration index and is believed to impact the water quality of the main stream. The influence index of Geumho River and Nam River between 2015 and 2016, which have a large amount of discharge, was the highest among the tributaries in terms of the load material balance. Showing the highest average concentration and average load in the index assessment, Geumho River is believed to require an intensive management for improving the water quality of the main stream. Furthermore, when the cumulative percentage of the average concentration and average load was compared based on the water quality improvement of the tributaries mixed to Nakdong River, which was set to 60%, Geumho River, Nam River, Topyeong-cheon, and Cha-cheon, which showed the highest ratio in that order, were determined to require a water quality management program as a priority.