In order to understand the impact for decomposition of blue-green algae Microcystis on water quality, the algae were cultivated with collection of natural population during approximately one month, when water-bloom of Microcystis dominated at August 31, 1999 in the lower part of the Okchon Stream. The enrichment of inorganic N·P nutrients didn't in algal assay and the effect of Microcystis on water quality was assessed from the variation of nutrients by algal senescence. Microcystis population seemed to play a temporary role of sink for nutrients in the water body. Initial algal density of Microcystis was 2.3×106 cells/ml. When Microcystis population died out under light condition, algal N·P nutrients between 9∼12 days affected to increase of biomass after reuse by other algal growth as soon as release to the ambient water. However, cellular nutrients under dark condition were almost moved into the water during algal cultivation. NH4, NO3 and SRP concentration were highly increased with 160, 17 and 79 folds, respectively relatve to the early. As a result, the senescence of Microcystis population seemed to be an important biological factor in which cause more eutrophy and increase of explosive algal development by a lot of nutrients transfer to water body. There are significantly observed an effort of reduce for production of inner organic matters such a phytoplankton as well as load pollutants from watershed in side of the water quality management of reservoir.

본 연구에서는 금강 대청댐하류의 본류구간에서 갈수시간에 대해서 WASP5모형 중에서 수질모의 부분인 EUTRO5모형과 1차원 정상류 수리모형인 HEC-2모형을 연계한 수질모형을 이용하여 대청조정지댐으로부터 강경수위표 지점까지 수질의 변화를 모의하였다. 수질 및 유량자료의 수집을 위하여 대청댐으로부터 금강하류에 위치한 주요 수위표지점에서 1998년 12월, 1999년 1월과 3월의 3회에 걸쳐 관측하였다. 수질모의모형은 1999년 1월 자료를 이용하여 보

농촌 소하천의 수리학적 및 수질특성을 반영한 모형을 개발하였다. 모형구조 설계시 제어체적 기법을 활용하여 하천 형상, 수질 및 유량의 변화가 심한 농촌 유역의 소하천에 대한 수질의 모의하였다. 개발한 모형에 난수발생기법을 도입하여 최적 반응계수와 모형구조를 추정하였다. 또한 모형 보정기준의 일반화를 위해 동의지표와 효율계수를 도입하여 매개변수추정의 신뢰성 향상을 도모했다. 모형의 적용성을 검증하기 위해 경남 김해시 한림면 용덕천에서 수질을 채취하여 분석

본 연구는 최근 하천유지유량에서 중요한 위상을 차지하고 있는 하천생태계에서 어류 서식처를 보전하고 복원하는데 필요한 적정 유량을 산정하는 것이 주된 목적이다. 어류 서식처를 적절히 유지할 수 있는 연과 월갈수량을 산정한다. 이 갈수량을 이용하여 점변 흐름에서 어류 서식처 제공에 필요한 수심과 유속을 모의하고, 또한 수온과 용존산소를 예측한다. 예측된 각 갈수량별 서식 조건과 각 성장단계별 어류 서식처 요구 조건을 도식적으로 비교하다. 이 과정을 남한강의

A study on the variational characteristics of water quality and phytoplankton biomass by principal component analysis(PCA) was carried out in Kogum-sudo from February to October in 1993. We analyzed PCA on biological factors such as chlorophyll α and phytoplankton cell numbers for centric and pennate diatoms, phytoflagellates, and total phytoplankton as well as physico-chemical factors as water temperature, salinity, transparency, dissolved oxygen(DO), saturation of DO, apparent oxygen utilization(AOU), chemical oxygen demand(COD), nutrient (ammonia, nitrite, nitrate, phosphate and silicate), N/P ratio and suspended solid(SS). The source of nutrients supply depended on the mineralization of organic matters and inputs of seawater from outside rather than runoff of freshwater. The phytoplankton biomass was changed within short interval period by nutrients change. And it was controlled by the combination of several environmental factors, especially of light intensity, ammonia and phosphate. The marine environmental characteristics were determined by the mineralization of organic matters in winter, by runoff of freshwater including high nutrients concentration in spring, by ammonia uptake and high phytoplankton productivity in summer, and phosphate supplied input seawater from outside of Kogum -sudo in autumn. And Kogum-sudo was separated with 2 regions by score distributions of PCA. That is to say, one region was middle parts of straits which was characterized by the mixing seawater and the accumulated organic matters, other one region was Pungnam Bay and the water around Kogum Island which was done by high phytoplankyon biomass and productivity year-round.

The work on the eutropication of Youngsan river was conducted from Jul. 1997 to Jun. 1998. The value of water temperature in the study area varied from 4℃ to 32℃ with an annual mean of 17.5℃. DO varied from 4.0㎎/ℓ to 13.5㎎/ℓ with an annual mean 10.2 ㎎/ℓ. BOD varied from 0.8㎎/ℓ to 6.4㎎/ℓ with an annual mean 3.1㎎/ℓ. COD varied from 4.6㎎/ℓ to 9.0㎎/ℓ with an annual mean 6.38㎎/ℓ. Nitrate varied from 1.58㎎/ℓ to 6.77㎎/ℓ with an annual mean of 3.475㎎/ℓ. Total-nitrogen varied from 2.14㎎/ℓ to 8.38㎎/ℓ with an annual mean of 5.083㎎/ℓ. Total-phosphate varied from 0.035㎎/ℓ to 0.588㎎/ℓ with an annual mean of 0.128㎎/ℓ. Chl.a varied from 1.8㎍/ℓ to 75.0㎍/ℓ with an annual mean of 19.55㎍/ℓ. The euthrophic state index of Carlson^16) were showed 61.8(TP) and 71(SD) value

The pollution characteristics of groundwaters in Taegu City and correlation coefficients(r) between water pollution indicators were investigated for two years from January 1996 to December 1997. Volatile organic compounds such as TCE(tri-chloroethylene), PCE(tetrachloroethylene), 1,1,1-trichloroethane, THM(trihalo-methane), dichloromethane, pesticides such as diazinon, parathion, malathion, and toxic inoganic matters such as As, Hg, Se, Pb, Cd, Cr6+ , CN were not detected in the groundwaters. Mean values of groundwater pollution indicators were below drinking-water standards, but hardness, KMnO4-C(potassium permanganate consumption), evaporate residues, SO4-2, Fe, NO3- -N, color and turbidity exceeded a little in some samples. As groundwater became deeper, hardness and evaporate residues remarkably increased, but KMnO4-C, NO3- -N, Cl-, color, turbity and bacteria decreased. KMnO4-C, evaporate residues, Cl- and SO4-2 were very high at industrial and commercial areas, and NO3- -N and NH4+-N were very high at agricultural and forest areas. It showed high positive significances in the relationships between hardness and each of evaporate residues, SO4-2, Zn and Mn, KMnO4-C and each of color, turbidity and Zn, color and each of turbidity, Cu, Zn and Mn, turbidity and each of Fe, Cu, Zn and Mn, and evaporate residues and each of Cl-, SO4-2 and Zn.

It is essential for port planning, coastal zone management and environmental impact study to analyze the variation of current and water quality due to the development of water area and discharged water from estuary barrage and basin etc. Mokpo sea area downstreams from a long river and two large basins, the Yongsan river and Yongam-Kumho basins discharging much of water through water gates for the purpose of flood control and prohibition of salt intrusion to the inland fresh water area. In this study, the numerical calculations were carried out for the analysis of diffusion characteristics due to discharging operation, adapting the results of tidal current simulation ADI methord is applied to the governing equation for the movement of sea water and diffusion and 6-point method to the advection terms of diffusion equation. As the results of this study, it is known that the discharging operation causes increasing and/or decreasing of current velocity and enlarging and/or depressing of pollutant diffusion limits depending on the distance from the discharging gates and the mode of discharging operation. To utilize these result, the linked gate operation and the method increasing exchange of sea water must be considered.

This study has been performed to evaluate mineral water quality by using four parameters [Mg]/[Ca], [Na]/[K], [Mg]+[Ca]/[Na]+[K] and total hardness(as CaCO3 ㎎/ℓ). The four parameters has been ploted in a general scale and logarithmic scale, respectively. The method of general scale is not applicable for evaluation on several parameters. Therefore, The logarithmic scale is applied instead to settle the problem. The evaluation of the water quality is based on standard sample S, and the results of the 6 domestics and 5 overseas sample evaluation are as follow. At present, evaluation of the water quality on the mineral water can be done by using four parameters calculated from only cation concentration printed on the bottle's marking.

지하수 수질 감시를 위한 관측망의 설치는 지하수자원의 보호를 위해 매우 중요하다. 그러나 현재 지하수 수질 관측망의 설계는 합리적인 방법보다는 현장전문가의 경험과 직관에 의존하는 경우가 많다. 본 논문에서는 3차원 수질모의와 최적화를 이용하는 지하수질 관측망의 설계방법론을 제안하였다. 설계과정은 다음의 세 가지 경우로 정형화되었다. (Ⅰ) 평균농도를 감시하는 위치를 선정하되 관측정의 수기 제한되는 경우, (2) 최대농도를 감시하는 위치를 선정하되 관측정

북한강 수계의 농업소유역에 대하여 하천수(2년)와 지하수(1년) 수질을 모니터링하여 분석하였다. 농업소유역의 주요한 비점원 오염물질인 총질소, 질산성 질소, 총인, BOD, TSS 및 대장균 농도를 주기적으로 측정하였다. 계절에 따른 수질의 변화 및 지하수와 하천수 수질과의 관계 비교를 통하여 토지이용이 수질에 미치는 영향을 분석하였다. 연구유역의 지하수 수위와 총질소, 질산성 질소의 농도의 벼농사와 밀접한 관련이 있었고 지하수와 하천수의 질소농도의 변

The aim of this study is to develop the water quality simulation model (BAYQUAL) that deal with the physical, chemical and biological aspects of fate/behavior of pollutants in the bay. BAYQUAL is a two dimensional, time-variable finite element water quality model based on the flow simulation model in bay(BAYFLOW). The algorithm is composed of a hydrodynamic module which solves the equations of motion and continuity, a pollutant dispersion module which solves the dispersion-advection equation. The applicability and feasibility of the model are discussed by applications of the model to the Kwangyang bay of south coastal waters of Korea. Based on the field data, the BAYQUAL model was calibrated and verified. The results were in good agreement with measured value within relative error of 14% for COD, T-N, T-P. Numerical simulations of velocity components and tide amplitude(M2) were agreed closely with the actual data.

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 quality, based on the information obtained from the results of cluster analysis. The results of cluster analysis show that the water quality characteristic 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 on the 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.

It is very important to quantitatively assess the movement of sea water and pollutant dispersion before or after constructing shore structures such as breakwater considering marine environment and long-term utilization of those structures. This assesment is possible through the use of simulation models designed to predict water movement and pollutant dispersion in a certain area. In this study the numerical computations were carried out to predict the sea water quality in the Ilgwang Harbor located at the east coast of Pusan. The flow patters were investigated before and after the development of Ilgwang Harbor. The computational models adopting ADI Method (Alternating Direction Implicit Method) were used here and were already verified from the previous studies. As a results of this study the tidal exchange in Ilgwang Harbor after development proved to be worse due to the increased semi-enclosed at the harbor limit. In order to improve the water quality of this area after development a new method was proposed to improve water quality in the semi-enclosed bay by creation and control of tidal residual currents. For this purpose the unsymmetric structures so called bottom roughness were introduced in this study. The simulation was carried out on the basis of the study by Komatsu et. al. and Gug and we made a conclusion that it is possible to generate a new tidal residual current and to increase the tidal exchange by application of bottom roughness arrangement.

The relationship between primary productivity and changes in water quality was investigated at Mulgum station, a site downstream of the Nakdong River, Korea. Phytoplankton production was characterized by blooms of Microcystis aeruginosa during the summer and Stephanodiscus hantzschii during the winter. Primary production and secondary production by bacterioplankton ranged from 1.5∼53.5㎎·C/ℓ'day and 0.1∼0.3 ㎎·C/ℓ'day, respectively. Distribution of total organic carbon appeared to be highly correlated with phytoplankton biomass, especially during blooms of M. aeruginosa, when particulate organic carbon was 81% of total organic carbon and the main source of organic materials supplied into the water. The correlation coefficient between chlorophyll-a and BOD was 0.86. Thus it was concluded that autochthonous phytoplankton mostly affected the BOD level. Total bacterial numbers were also highly correlated with chlorophyll-a (r2=0.84) and the bacterial community appears to be regulated by phytoplankton biomass in this area.

밀양강 수계 7개 지점에 대하여 1997년 4월부터 12월까지 5회에 걸쳐 채집된 저서성 대형무척추동물의 군집분석 및 저서성 대형무척추동물에 의한 생물학적 수질평가 결과를 요약하면 다음과 같다. 분류군은 총 3문 8강 15목 37과 45속 81종으로서 빈모류 1종, 거머리류 2종, 복족류 6종, 부족류 5종, 갑각류 2종, 곤충류 65종으로 곤충류가 가장 많았다. 전체 지점에 대한 평균 개체수 현존량은 815개체/㎡였다. 이 중 곤충류(약80%)가 가장 많았으며, 다시 곤충류 중에는 하루살이류(약 70%)와 날도래류(약 18%)가 주를 이루었다. 각 지점별 평균개체수 현존량을 보면, 제1지점인 청도천의 경우 262개체/㎡(32.2%)로서 가장 많은 출현율을 보였고, 제7지점인 밀양강 끝지점의 경우 38개체 /㎡(4.7%)로서 가장 출현율이 낮았다. 전체 평균 수준에서의 제1우점종은 Ecdyomurus levis Navas였으며, 우점도지수는 0.3이었다. 각 지점별 우점종을 보면 제1지점부터 제5지점까지는 Ecdyomurus levis Navas이였고, 제6지점과 제7지점은 Hirudinidae sp.1이었다. 그리고, 전체 평균 수준에서의 다양도지수는 2.66이었다. 조사지점별 평균 다양도 지수를 보면 제4지점이 가장 높았으며(H'=3.47), 다음은 제2지점, 1지점, 3지점, 5지점, 6지점, 7지점의 순이었다. 생물학적 지표종을 중심으로한 수질평가에 의하면, 밀양강 전체의 평균은 군오염지수(GPI) 1,49로서 β-mesosaprobic의 II급수로 평가되었다. 각 지점별로는 제3지점의 경우 Oligosaprobic의 I급수로서 가장 양호한 수질이었고, 제1지점과, 제2지점, 제4지점, 제5지점은 β-mesosaprobic의 II급수로, 제6지점은 β-mesosaprobic의 III급수로 평가되었다. 그리고, 제7지점은 α-mesosaprobic의 III급수로서 가장 수질이 불량한 것으로 평가되었다.

This study was carried out to evaluate off-shore water quality and to draw marine pollution map to Southern sea in Korea by bioassay using gametes and early development system of Asterias amurensis. From the bioassay, it was determined that the water qualites of Southern sea maintained the grade Ⅱ, because development of A. amurensis were moderately inhibited. However, Sunchon, Kwangyang, and Jinhae Bay belonged to grade Ⅲ, because development of A. amurensis were strongly inhibited. This could be due to the inflows of several river systems and poor water circulation. The water quality at Yosu island was the grade I, because A. amurensis were not inhibited in its early development.

The analysis of groundwater quality in Kyungnam Province was conducted using monitoring results obtained during 1994. According to the analysis, most heavy metals and pesticides listed in Korean drinking water standards were not detected in Kyungnam Province groundwater, but arsenic and volatile organics such as TCE and PCE were detected. Four inorganic contaminants were detected and frequency of violating the standards was in order of NO_3-N, F^+, As, NH_3-N. Of organics, TCE and PCE were the only contaminants detected. TCE more frequently violated the standards than PCE. Correlation was investigated among contaminants detected in Kyungnam Province groundwater. The correlation results showed that high correlation existed among dissolved solids, hardness, and SO_4^2-.

In order to manage the water quality from the flowing streams in Cheju Island, the characteristics of water quality was investigated from August, 1996 to May, 1997 and the pollutant loadings for future were estimated from the watershed at each stream. Comparing the mean concentrations of each water quality with the criterion of water quality in river, it was under I class except for Changgo Stream, for DO, under I class at the whole station for SS and under Ⅱ class for BOD. As the pollutant loadings at each stream in 2020 is compared with those in 1996, the estimated results are as follows : 1) for BOD, 59% at Donghong Stream, 24% at Yeonoe Stream, 44% at Ohngpo Stream and 57% at Changgo Stream. 2) for T-N, 91% at Donghong Stream, 76% at Yeonoe Stream, 63% at Ohngpo Stream and 89% at Changgo Stream. 3) for T-P, 69% at Donghong Stream, 42% at Yeonoe Stream, 45% at Ohngpo Stream and 73% at Changgo Stream The point source loadings discharged through combined sewer could be treated at sewage treatment plant. However, the expected slow decreasing rate of BOD, T-N, and T-P loadings is due to the part of untreated nonpoint source loadings. Nonpoint source loading overflow typically occurs when the flow of stormwater combined with sewage exceeds the capacity of the interceptor sewers. Since most of the sewers used in Cheju Island are the combined sewers, the combined overflow sewage is bypassed into the receiving water area after a rainstorm. Therefore, a means to control nonpoint source loadings should be considered for the river and marine water quality management.

It is necessary to quantitatively asses the influence of tidal currents to analysis the coastal current patterns before or after constructing offshore structures like as breakwaters. This assesment can be made through the use of simulation models designed to reproduce the water movements of the area. And it is very important to predict a phenomenon of pollutant dispersion in the area. In this study, in order to predict the changes of sea water quality for the port development plan, Ilgwang harbour, located at the east coast of Pusan, the numerical computations were carried out. The flow patterns were investigated before and after the development of the harbour bay and coastal area connected on it. The computational models are an extension of earlier work on the flow which used the ADI Method (Alternating Direction Implicit Method) in appling to Osaka Bay by KANEKO et al. The transport of pollutant constituents depends upon the currental characteristics of the water-transporting medium. In the currental flow model, water velocities and water levels are computed throughout the regions of it. These value are then used in the mass-balance equation to obtain the pollutant-constituent transport. As a result of this research, the present water quality of Ilgwang harbour and the coastal areas connected on it was proved out some good condition. The changes of sea water quality due to the port development plan of the Ilgwang habour bay and the coastal area were not large compared with the present condition, but it will be likely able to get worse by increasing the semi-enclosed areas in the harbour bay. In order to improve the water quality of the area after development, the method to activate tidal exchange in the area can be needed, as a mitigation technique.