When the Juam multipurpose dam which is connected with existing large water supply facilities is finished, water environment is changed from stream to lake. The changed quality of water should be examined. In this study, the result of water quality forecasting is analysed and an effective management plan of water quality is presented. In this study, the WASP5 model that is a dynamic water quality simulation model was selected to forecast the water quality. This model forecasts movement of change of pollutants. For an application of the model, the subject areas were divided into seventeen sub-areas by considering change temperature depending measuring points and on depth of water. Meteorological data collected by the meteorological observatory and data about quality measured by the Korea Water Resources Development Corporation were used for an operation of the model. As a result of quality examination through quality data and estimated pollutant loading, the water quality environment criterion was grade Ⅱ and the nutritive condition was measured as meso-graphic grade. In this study, an effective management was planned to improve water quality by reducing pollution load. According to the result of examination, when more than 30% of BOD was reduced it was recorded that the environment standard of water quality was improved to the second grade.

This study was performed to investigate the physico-chemical properties and phytoplankton concentration from February to December, 2007 in Gwangju area reservoirs. Water samples from 20 reservoirs were analyzed. As results of the water quality analysis, the average pH was 7.6 and annual pH were 6.3 ～9.6. The higher pH of 8.6 ～ 9.6 were showed from March to August due to eutrophication. Chlorophyll-a concentration ranged from 0.4 to 164.3 mg/㎥. The highest chlorophyll-a concentration was observed in August. BOD was correlated with SS, T-N, and Chlorophyll-a(R=0.82, 0.90 and 0.84) respectively. COD was correlated with BOD, SS and Chlorophyll-a(R= 0.89, 0.77 and 0.76) respectively. The T-N/T-P ratios were 4～281, so phosphorus was considered to be the limiting factor in most of points. The trophic state showed eutrophicate states in Gwangju reservoirs. Therefore it was necessary to monitor continuously. In order to monitor the reservoirs, an algae prediction system must be used.

This study tried to investigate and analyze the actual state such as the regional, classified, and material characteristics of the water quality in order to research the several factors by which the filtrated water of the total 250 cases can be polluted in the water tank. The 215 points (86%) clean the water tanks twice a year regularly and J-city has done the best job of cleaning the water tanks. The fifty points (20%) of the total 250 investigation points examine the water quality of the water tanks every year, however, the 175 investigation points (70%) do not execute the inspection of water quality. In the case of the regional characteristics in the water quality, the 23 points (46%) in H-county, the 17 points (34%) in S-county, and the 16 points (32%) in G-city are incongruent in the standard, and the incongruity ratio of the water quality in J-city is the lowest. The result of the classified incongruity shows that total coliforms were found at the 61 investigation points, mesophilic bacteria were found at the 27 points, and turbidity was found at the 12 points. In the case of the material incongruity, concrete was found at the 63 investigation points as the most distinguished factor, and FRP (fiberglass reinforced plastic) at the 23 points, SMC (sheet molding compound) at the 12 points, and stainless steel was found at the 2 points.

병성천의 기후변화에 대한 영향을 평가하기 위하여 CGCM 3.1 T63의 A2 시나리오를 미래기후정보로 선택하였으며, CGCM으로부터 획득된 강수자료를 비롯한 미래기후자료는 다지점 강수발생기를 통하여 지역기후자료로 규모내림되어졌다. 상기 규모내림된 기후자료는 병성천의 유출량 및 수질을 예측하기 위하여 SWAT모형의 입력자료로 사용되었다. 간단한 민감도분석의 결과로서, 대기 중 이산화탄소 농도의 증가는 증발산량의 감소와 토양수분의 증가를 유발하여 유출량을

To investigate the influence of water area calmness on the red tide development, runoff phenomena due to antecedent precipitation of red tide development day were analyzed. There were examined the water quality variation properties at about the same time of the red tide develop. The red tide was developed when the stage and discharge nearly had not changed. It was estimated that the stability of particle behavior in the mouth of river effected on the red tide develop. Also, the concentrations of CODMn were increased about 241~629% when the red tide developed.

본 연구에서는 SWAT(Soil and Water Assessment Tool) 모형을 이용하여 미래 기후변화가 충주댐 유역(6,585.1 km)의 하천수질에 미치는 영향을 분석하고자 하였다. 미래 기상자료는 IPCC에서 제공하는 A2, A1B, B1 배출시나리오를 포함하는 ECHAM5-OM 모형의 결과를 과거 30년(1977-2006, baseline period) 기후자료를 바탕으로 편이보정(bias correction)과 Change Factor

An objective of this study is as follows: 1) performing sensitivity analysis and parameter estimation of RMA2 and RMA4 models for the West-Nakdong River, 2) drawing up alternatives of gates-operation for water-quality enhancement, and 3) quantitative evaluation of methodology of 'flow-restoration by gates-operation' among 'Comprehensive Plan Improving Water-Quality in the West-Nakdong River(WNR)' with the target water-quality(BOD at Nakbon-N point: below 4.3 mg/L). The parameters for the RMA2 (depth-averaged two-dimensional flow model) and RMA4 (depth-averaged two-dimensional water-quality model) were determined by sensitivity analysis. Result of parameter estimation for RMA2 and RMA4 models is 1,000 Pa․s of the eddy viscosity, 20 of the Peclet number, 0.025 of the Manning coefficient, and 1.0 m2/s of the diffusion coefficient. We have evaluated the effects of water-quality enhancement of the selected alternatives by numerical simulation technique with the models under the steady-state flow condition and the time-variant transport condition. Because of no-resuspension from river bottom and considering BOD as conservative matter, these simulation results slightly differ from real phenomena. In the case of 50 m3/s of Daejeo-gate inflow, two-dimensional flow pn results result represents that small velocity occurs in the Pyungkang Stream and no flow in the Maekdo River. In the WNR, there occurs the most rapid flow near timhae-bridge. In the WNR, changes of water-quality for the four selected simulation cases(6, 10, 30, 50 m3/s of the Daejeo-gate inflow) were predicted. Since the Daejeo-Gate and the Noksan-Gate can be opened up to 7 days, it would be found that sustainable inflow of 30 m3/s at the Daejeo-gate makes BOD in the WNR to be under the target of water-quality.

The water quality of reservoir can be controled by water quality prediction model because it can not only grasping the present water state but also predicting the water quality in future. In this study, WASP model is used to predict the water quality of Chungju reguration reservoir. This model has some special option which predicts the pollutant outflow phenomenon caused by the contamination sources. So this model is widely used because that can present the scientific basis in this field. This model can help the managers make the right choice of water quality policy. Environmental grade of Chungju reguration reservoir is in Ⅲ,Ⅳgrade which is in bad condition comparatively. The water contamination will be in poor as the year passes. When considering T-N, T-P which are the nutrient to control eutrophication, the concentrated administration about contamination sources is in urgent.

본 연구의 목적은 댐방류에 의한 하류하천의 수질개선효과를 대체댐이 아닌 하수처리시설을 대체시설의 비용으로 적용하여 국내 실정에 맞게 편익으로 산정하는 방법론을 제시하는 것이다. 이를 위해 댐을 대체하는 시설은 댐의 방류수와 동일한 기능을 제공해야 하고, 두 시설간의 비용을 객관적으로 비교할 수 있어야 한다. 본 논문은 대체비용법을 이용하여 수질개선편익을 산정하기 위해 대체시설(하수처리장)의 비용 산정방법, 비용 편익분석 관련 기준인 내용연수와 대수선비율

신뢰도 높은 수질 모의를 위해서는 유역 내 정확한 유출 모의가 반드시 선행되어야 한다. 본 연구에서는 연속방정식과 운동파 근사에 의한 Manning의 식이 결합된 비선형 저류방정식에 근거한 하도추적법과 금일 강수량을 고려하여 시간적으로 가중 평균된 유출곡선지수를 산정하도록 개선된 지표유출계산 모듈이 수질 모의에 미치는 영향을 분석하였다. 이를 대표적 준분포형 모형인 SWAT에 탑재하여 충주댐 유역에 적용하여 각 개선모듈별 독립적인 분석과 전체 개선의 효

This study was investigated to control the corrosion and scale at the cooling water system in steel works. Laboratory and field tests were performed for the indirect cooling water system of plate mill. Throughout the experiment, various factors such as leakage of pipes, heating rate and capacity, and the reaction between existing and substitute inhibitors were carefully monitored. The results showed that the harmful effect of high temperature could be minimized, and satisfactory corrosion/scale controls were effectively achieved using inhibitor, even at the increased temperature of 80℃. The batch and field tests in the gas scrubbing cooling water system of blast furnace and cooling water system of corex plant indicated that the new inhibitor was more effective for the prevention of corrosion and scale than the existing one.

Temperature, salinity, COD, DIN (Dissolved Inorganic Nitrogen), DIP (Dissolved Inorganic Phosphorus), and Chlorophyll a obtained from the southern coastal waters during the period of 2003 to 2005 were analyzed. Variability in temperature was not found between groups in southern coastal waters, but significantly different depending on sampling sites (p<0.05). The average temperature in 2003 estimated at 18.33℃ that was annually increased by 2005 and significantly different based on statistics (p<0.05). Unlikely to temperature, salinity was significantly different depending on sampling sites, as well as monthly variations (p<0.05). Likewise to temperature, the value of salinity was annually increased. COD estimated at the average of >1.7 mg l-1 for three years, indicating optimal water quality. The fluctuations of nutrients were extremely shown in different sampling sites and monthly variations. Chlorophyll a recorded above 2.0 μg l-1 which was associated with high primary phytoplankton, whereas it showed much fluctuations in temporal and spatial, In particular, Tongyong, Jaranman, Jinjuman, and Samcheonpo located in the southeast were the highest fluctuations in water quality than any other regions. The correlation between salinity/COD and nutrients/chlorophyll a was strongly negative or positive, which was possibly associated with much the introduction of run-off water as well as rainfall in summer.

본 연구는 농촌소유역(1.21 )에서 다양한 공간입력자료의 해상도가 SWAT(Soil and Water Assessment Tool) 모형의 수문-수질 모의결과에 미치는 영향을 분석하고자 Case A(2 m DEM, QucikBird 토지이용도, 1/25,000 토양도), Case B(10 m DEM, 1/25,000 토지이용도, 1/25,000 토양도), Case C(30 m DEM, Landsat 토지이용도, 1/25,000 토양도)에 해당하는 해상

The influence of the point source inflow on the water quality variation in the downstream of Hyeongsan River was investigated. As the results of seasonal variation, the pollutant concentrations of dry season were 1.5~4 times higher than those of wet season. The increase rate of BOD5, CODMn, T-N, T-P due to point source were ranged to 8.1~42.6%, 7.3~41.9% and 17.1~207% as the inflow of P1, P2 and P3, respectively. After P1, P2 and P3 inflow, the accumulated increase rate were 64.3%, 32.6%, 93.1% and 258.9% in BOD5, CODMn, T-N, T-P, respectively. It was found that the influence of point source inflow on the water quality in the downstream of Hyeongsan River is severe.

하도내에서 발생하는 유출량 및 TOC 자료는 비선형성이 강한 자료임에 따라 홍수에 대한 재난대응과 수질의 상시감시를 위해서는 자료의 특성 분석과 예측에 관한 연구는 필수라 할 수 있다. 따라서 본 연구에서 유출량 및 TOC, TOC부하량 자료에 대한 웨이블렛 변환에 의해 최종분해된 최종파형분해단계의 근사성분과 상세성분을 이용하여 예측모형을 개발하였다. 그 결과 기존 인공신경망 모형에서 관찰되었던 시계반대 방향으로 전이되는 지속현상의 극복 가능성을 보여주

This study intends to provide the necessary basic data needed for predicting the water quality and examining changes in water quality on the basis of the hydrological changes: an outflow or the character of a flow by investigating the interaction of the parameters through the estimation of optimal parameters need for predicting the water quality of the dam basin and the sensitivity among those estimated parameters. Im-Ha Dam in the upstream area of the Nakdong River was selected for analysis, and the water quality survey data necessary for parameter estimation was based on the monthly water quality data (water temperature, BOD, T-N and T-P) between December 1, 2005~November 31, 2006. K1C(the saturated growth rate of plant plankton), K1RC (endogenous respiratory quotient of plankton), KDC(deoxidized ratio), K71C(minealized ratio of dissolved organic phosphorus), K83C(mineralized ratio of dissolved organic nitrogen) have been considered as the factors of the water quality performed in this water quality simulation, that is, the most effective parameters on BOD, T-N and T-P. In the result of the analysis of the sensitivity, KDC(deoxidized ratio) was the most sensitively reacted parameter on BOD and it was K71C(mineralized ratio of dissolved organic phosphorus) and K83C(mineralized ratio of dissolved organic nitrogen) on T-N and T-P. It is considered that it will be possible to apply the most optimal parameter to an analysis of the water quality simulation at Im-Ha Ho basin in the goal year by examining the interaction of the parameters through the parameters sampling which are able to applicable to prediction of the water quality and the analysis of the its sensitivity, in the future, also the analysis on the basis of the hydrological conditions: an outflow or the character of a flow will be needed.

This study was carried out to evaluate the effect of water quality of cooling tower on Legionella pneumophila disinfection using Ru/Ti electrode. The influences of parameters such as pH, turbidity, CaCO₃ and TOC were investigated using laboratory scale batch reactor. Oxidants such as free Cl, ClO₂, H₂O₂ and O₃ were measured. The results showed that all of the water quality parameters of cooling tower had deteriorated disinfection of Legionella pneumophila. When the turbidity, CaCO₃ and TOC was increased, oxidants which was generated during electrolysis was decreased. pH, free Cl, ClO₂ and H₂O₂ concentration were decreased with the increase of pH, whereas O₃ concentration was increased with the increase of pH. The order of effect of water quality on the disinfection performance for Legionella pneumophila was turbidity > CaCO₃ > TOC > pH. To obtain the safety standard (1000 CFU/L), the simultaneous increase current and NaCl dosage was needed.

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3',4,4',5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs from PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and 0.17 ug/㎖ and 713.42 ㎍/g and 3.73 ㎍/g, respectively, which contained 20～40 times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.

본 연구는 조건부가치평가법 중 이중양분선택형 질문을 사용하여 안양천 유역의 수질개선에 대한 지불의사를 추정하였다. 선형로짓모형에서 전체 응답자의 지불의사액은 4,930원이었으며 서울지역 거주민과 경기지역 거주민의 차이는 없는 것으로 추정되었다. 응답자들은 전반적으로 조건부 시장을 잘 받아들였으며 가구당 월평균 3,860원에서 5,101원의 지불의사를 가지고 있는 것으로 분석되었다. 이 값을 전체지역으로 확장하면 연간 약 83.0억원에서 109.7억원에