• Journal of fish pathology
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• v.4 no.1
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• pp.23-30
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• 1991

This paper deals with the distribution of coliform group bacteria and the environmental factors in Suyeong Bay from November 1990 to February 1991. The ranges of environmental factors were as follows : Salinity 16.84~34.93%, Dissolved Oxygen $0.58{\sim}6.79m{\ell}/{\ell}$, COD 0.48~5.06 ppm, Nitrite $0.42{\sim}18.82{\mu}g-at/{\ell}$, Nitrate $0.50{\sim}53.23{\mu}g-at/{\ell}$, Ammonia $3.73{\sim}56.16{\mu}g-at/{\ell}$, Silicate $5.18{\sim}147.29{\mu}g-at/{\ell}$. The coliform group and fecal coliform group ranged $1.1{\times}10^2{\sim}2.4{\times}10^5/100m{\ell}$, $1.7{\times}10{\sim}3.5{\times}10^4/100m{\ell}$ each other. The ratio of TC/FC was 1.73~58.49 during study periods. Among the composition of coliform group, E. coli was dominent(64.4%), which was appeared all studying stations. E. coli I type was accounted for 97.4% in the E. coli.

• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.42-49
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• 2008

For this study, we collected fishes of four times at the four site during June 2006 ${\sim}$ September 2007. In the result, the tolerance and omnivore species like a Carassius auratus and Pseudorasbora parva were largely dominated over all, and the sensitive species was not appeared at all except S4 in Shingu reservoir. This reservoir was appeared the simplified of trophic guild was shown in Shingu reservoir. Demonstrating that the omnivore species was occupied 78% of whole. According to the water chemistry data set obtained from the Korea Rural community & Agriculture corporation during $2002{\sim}2005$, the Shingu reservoir showed severe eutrophication and water pollution, therefore the increase of primary production and frequent algal blooms had been occurred. On the other hand, ecosystem health of reservoir was appeared "Fair${\sim}$Poor", and we judged that eutrophication and water pollution were due to this. Consequently, we thought that interception of nutrients and organic matters from the farmland and village and management of reservoir would be need, after this.

• Applied Microscopy
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• v.32 no.2
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• pp.175-183
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• 2002

In this study, we carried out immunostaining and immunogold labeling with rabbit anti-dopamine (TH) and rabbit anti-calbindin-$D_{28K}$ to examine the characteristics and functions of the neurons that secrete neurotransmitters in optic lobes of Todarodes pacificus and Octopus minor inhabiting the Korean waters. The obtained results are as follow. In the immunostaining with anti-dopamine, only a few of the large amacrine cells in an the upper part of an outer granule cell layer and the cells forming the islands of medulla showed positive reaction in Todarodes pacificus, while $2{\sim}3$ cells in the upper and middle parts of an outer granule cell layer and more than 5 cells in the islands of medulla reacted positively in Octopus minor. For the case of anti-calbindin case, $2{\sim}3$ small amacrine cells in the upper portion of the outer granule cell layer and $1{\sim}2$ cells which are located in the lower part of an inner granule cell layer showed positive reaction in Todarodes pacificus, while, in Octopus minor, 4 cells in the outer granule cell layer reacted positively, no immunoreactive cell being found in the inner granule cell layer. As a result of performing the immunogold labeling, relative large number ($17{\sim}26$) of gold particles were labeled per $0.5{\mu}m^2$ of the cytoplasm of the cells which showed the immunoreactivity to the anti-dopamine and anti-calbindin in Todarodes pacificus, however, small number (10) of gold particles were labeled in Octopus minor, which reach only half of the number in the Todarodes pacificus.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.525-534
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• 2005

A column experiment was performed to investigate the influence of the sludge cake development on the riverbed and the hydraulic gradient imposed by the drawdown at the well on the filtrate quality in order to offer a guideline in the design and operation of the riverbed filtration. Results show that the sludge cake on the riverbed plays an important role in the removal of the organic matter. Under the conditions of this study the COD removal rate increased from 17% to 50% along with the sludge cake development, which was equivalent to the BCOD removal of 22% and 67%, respectively. The active removal of the organic matter took place in the sludge cake and the upper 40 cm of the riverbed. As the flow rate increased owing to the increase in the head difference imposed on the column, the slope of the COD profile near the column inlet decreased, however, the profiles converged in about 40 cm from the inlet. In 10 days of sludge cake formation the dissolved oxygen was depleted at the depth of 70 cm, which suggests the denitrification can take place beyond the depth. This depth was further reduced to $20{\sim}40\; cm$ as the sludge cake developed. From this study the removal of organic matter can be expected through the riverbed filtration even with the depth of as shallow as 3 m, which is frequently met in Korea, while the removal of nitrogen through denitrification is not expected to be active under the condition.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1994.05a
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• pp.51-53
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• 1994

담수는 인간의 생존에 필수적인 요소이다. 우리는 매일 일정량의 물을 섭취하고 있으며, 일상에서 직접, 간접적으로 물과 관련되지 않고서는 생활할 수 없다. 지구 표면의 약 70%가 물로서 덮여 있다고는 하지만 인간의 생활에 직접적인 이용가치가 있는 담수(지표수)는 전체 물의 용적의 2%에 지나지 않는다. 한국의 연평균 강수량은 1,274mm로서 세계 연평균 강수량인 970mm보다 많은 편이나 인구 1인당 연간 강수량은 약 3,000m3으로서 세계 평균인 34,000m3의 11분의 1에 지나지 않는다. 수자원총량중 지하침투와 증발에 의해 손실되는 양을 제외한 하천유출량은 전체의 55%인 697억m3으로서 이것이 곧 가용수자원량이다. 그러나 하절기 강우집중도가 높은 우리나라 실정에서는 가용수자뭔량중 수자원총량의 37%가 홍수시 유출되고 실제 이용량은 수자원총량의 18%인 230억m3에 불과하여 인구증가와 함께 수자원의 가치가 더욱 증대하고 있는 실정이다. 더우기 지하수 이용량은 19억m3에 불과함에 따라 우리나라는 실제 이응수자 원량의 90% 이상을 지표수에 의존하고 있으며, 그 중 약 40%가 호소수로 구성되어 있다. 이러한 수자원 이용효율의 취약성으로 인해 제한된 수자원 용량과 생활 및 농공용수의 과수요에 따른 불균형으로 근래 많은 하천이 갈수기나 평수기시 친천화되어 가고 있어 수중생태계에 큰 위협을 주고 있다. 또한 이에 더하여 산업발달과 함께 수질오염원은 양적으로는 물론 질적으로도 증가일로에 있어 기존의 유기 및 중금속 오염물질을 포함해 수많은 신생 유기화합물질이 수계에 유출되고 있으며, 이에 더해 질소 및 인으로 대표되는 영양물질의 유입과다로 국내 대다수의 호수가 부영양화의 새로운 위협에 직 면해 있다. 우리나라에는 적은 유입유량에 큰 저수용량 및 긴 체류시간으로 대표되는 대규모 자연호는 없으며, 대부분이 매단위 강을 막아 형성된 체류시간 1년 이하의 인공호로서 그 중 안동호, 충주호, 대청호 등은 비교적 체류시간이 긴 호소형 인공호로, 팔당호나 기타 대부분의 호수는 체류시간이 짧은 하천형 인공호로 대별된다(Table 1). 이처럼 국내 호소는 국외의 자연 호와는 다른 구조적 특성을 가짐에 따라 부영양화 특성 역시 매우 상이하고, 호소형 인공호와 하천형 인공호간의 차이 역시 현저하여 일률적인 관리대책을 설정하기가 어려운 실정에 있다. 또한 각 호수의 유역특성이 상이함에 따라 호수별로 유역 오염원의 오염부하율이 현저히 달라(Table 2) 호수에 따른 특성적인 유역관리(Lake-specific management)가 요구되고 있다 정상상태(Steady state)가 아닌 국내 호소에 대해 국외 자연호의 인단순모델 (Simple phosphorus budget model)을 그대로 적용하는 것에 다소 무리한 점이 따르나, 평균적인 개념으로 OECD의 유역부하량 및 호소특성에 따른 부영양화 판정모델을 적용한다면, 국내 주요 호수는 모두 부영양 수준에 있다. 또 각 호수별로 부영양화 제어를 위해 요구되는 인의 삭감부하량은 상당량이 되어 현실적으로 관리가 이미 어려운 실정에 와 있다. 호수의 부영양화는 조류 발생으로 이어지며, 그에 따른 폐해는 각종 형태로 나타나는데 대표적으로 이취미 발생이나 유해조류에 의한 독성물질의 배출, 정수처리 과정의 THM 발생등이 주로 문제가 되고 있다. 따라서 국내 호수의 구조적 특성별 부영양화 실태를 파악하고 그에 따른 영향 및 관리방안에 관한 종합적 고찰이 차후 수질관리를 위해 요구되고 있으며, 특히 납조류로 대표되는 유해조류의 독성영향에 관한 연구는 시급한 실정에 있다.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.262-268
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• 2015

This study established an analytical method to simultaneously determine six organophosphorous pesticides [methyldemetone-S, diazinon, fenitrothion, parathion, phentoate, and O-ethyl O-(4-nitrophenyl) phenylphosphonothioate (EPN)] and carbaryl in water using a gas chromatography/mass spectrometry (GC/MS) system coupled with on-line micro extraction by packed sorbent (MEPS) and programmed temperature vaporizer (PTV) injector. Polystyrene divinylbenzene (PDVB) was used as a sorbent of MEPS. The effects of elution solvents, pH, elution volume and draw-eject cycles of samples on sample pretreatment process were investigated. Also, quality assurance and quality control (QA/QC) and the recovery of the pesticides in environmental samples were evaluated. The elution was performed using $30{\mu}L$ of a mixed solvent (acetone : dichloromethane = 80 : 20 (v/v)). Sample pretreatment processes were optimized with seven cycles of draw-eject of sample (1 mL) spiking an internal standard and sulfuric acid. At lower pH, the analytical sensitivity of diazinon decreased, but that of carbaryl increased. The method detection limit and the limit of quantification for this method were 0.02~0.18 and $0.08{\sim}0.59{\mu}g/L$, respectively. The method precision and accuracy were 1.5~11.5% and 83.3~129.8%, respectively, at concentrations of $0.5{\sim}5.0{\mu}g/L$. The recovery rates for all the pesticides except carbaryl in various environmental samples ranged 75.7~129.3%. The recovery rate of carbaryl in effluent sample was over 200% whereas carbaryl in drinking water, groundwater, and river water were in the acceptable range.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.65-70
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• 1970

This report is a part of the studies of the lower part of the Naktong River. The temperature and quality of the river water were investigated from May 1967 to June 1968. Except for Hadan which is a point located at the mouth of the river and much Influenced by sea water the average water temperature is generally below $10^{\circ}C$ up to the end of March, 10 to $20^{\circ}C$ from the beginning of April to the 1st-2nd ten days of May, and thereafter becomes above $20^{\circ}C$ which is adequate for the growth of warm-water fishes. The water again becomes below $20^{\circ}C$ at the beginning of October and becomes below $10^{\circ}C$ in December The difference of water temperature between at 7.00 a.m. and 4.00 p.m. is considerably great at Hadan, the mouth of the river, where the water is relatively stagnant. It shows an average monthly difference of 2.6 to $6.8^{\circ}C$ with a total average difference of $4.6^{\circ}C$. At the Kupo and Samrangjin stations the difference is very small For the basic data In the management of rivers, the water temperature should be measured twice a day at its highest and lowest temperatures, and the long term fluctuation of temperature should be investigated.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.96-108
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• 2011

Going abreast of high public concerns on the environment, the need of environmental modeling has been increased to assess the impact of space exploitation of environment. GIS offers potential solutions to the many problems encountered during water-quality modeling. But there are also many problems associated with the modeling. The preparation of necessary parameters for the modeling can be complicated. Also, the results from one model can be different from each other even the same area is analyzed. This paper aims to develop the data processing system to couple the Qual2E and HyGIS in which Qual2E input and output data files can be created, modified and processed using HyGIS and assess the performance of the system. A structural analysis and standardization of modeling are conducted to identify data flow and processing of Qual2E. Algorithms of the defined processors are designed and developed as component modules. The data model of HyGIS-Qual2E is designed, and GUI(Graphical User Interface) is developed using Visual Basic 6.0 and GDK.

• Journal of Korea Water Resources Association
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• v.40 no.11
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• pp.861-867
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• 2007

This Research analyzes the consumers' willingness to pay(WTP) for residential water on severe drought condition. The 7 large cities and 32 chronicle drought regions have been selected for this research survey. Results show that the consumers of large cities, which are relatively rich, think water quality is more important than quantity, but the consumers of 32 chronicle drought regions expressed just opposite. Dichotomous choice and open-ended questionnaire are mixed for the survey and Tobit model is applied in the analysis. As we expected, the higher the education level, the number of household member, and the income, the higher the WTP. When there is 25% reduction of supply, the WTP is about $2 per month. Contrary to the expectation, WTP is just slightly increased for 50% of water supply reduction. This is because of the resistance of tax as well as the limited actual experiences of water shortage so, they underestimated it. In any cases, actual WTP for actual water shortage is much higher than this result. More effective water supply and distribution schedule must be ready as a national and local level to prepare severe drought in the near future. Consumers are willing to pay higher price than the current level for water security. Water distributional system should be reconsidered and alternative source of water also be prepared.

• Journal of Environmental Policy
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• v.6 no.2
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• pp.47-70
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• 2007

In recent days, people's requests about water resources have been developed from managing quality and quantity of water resources to forming a river environment by restoring normal function of river. To meet these requests, it is necessary to establish the concept of environmental flows. In Korea, the environmental flows was introduced as a concept of river maintenance flows in a sense of river management. The function of river maintenance flows has been changed according to what the major issue is in that age such as navigation, water quality, and prevention of saline water intrusion. As the assesment of river maintenance flows in Korea focused mainly on the function of water usage oriented in human, it could not be defined and emphasized in a sense of ecosystem as a pure meaning of environmental flows. And while the existing river maintenance flows are included the assesment of flows, there is not a practical procedure to supply them and the efficient management in a sense of environment is not performed. The environmental flows should be further developed from the river maintenance flows and changed to a new concept focused on maintaining the health of ecosystem. In other words, the environmental flows should be defined as a necessary flows for maintaining the function of river and its original value, and be considered on the same or higher value of flows for maintenance of economic activity, recreation, and power generation.