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

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.

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.

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 conducted to evaluate water quality in the Keum River estuary using principal component analysis. The results was summarized as follow; Water quality in the Keum River estuary could be explained up to 70.40% by three factors which were included in the inffluent loading by the Keum River and Kyungpo cheon(38.99%), seasonal variation and organic matter pollution(19.05%), sediment resuspension and internal metabolism(12.35%). For spatial variation of factor score, artificial pollutant loading is highest at st.1, below Keum River barrage, and decreases toward the outer sea. For annual variation of factor score, factor 1 was highly related to artificial pollutant loading, and it was greatly increased in 1994. Also, organic matter pollution, sediment resuspension and internal metabolism were increased to every year. is necessary to control the nutrient loading by Keum river and Kyongpo cheon for Water quality management of estuary.

여러 소하천으로 이루어지는 수계에서 복잡한 물수지 요소가 여러 지점에서 발생하는 하천 말단 특히 감조지역에 수자원 시설물을 설치하고자 할 때 유입량의 추정이 문제가 되며 물수지 요소의 변동에 따라 말단의 유출량이 영향을 받는다. 이러한 문제는 하천의 유입.유출요소의 정형화를 필요로하며 소유역의 일유출량 추정 모형을 필요로 한다. WWASS 모형은 일별 유입량과 펼요수량 추정 모형으로써 DIROM을 사용하고 있고 물수지 요소들을 하천의 조절점(contro

낙동강 유역의 용수수급 불균형을 해결하기 위한 한 대안으로서 한강과 낙동강 유역을 서로 연계하여 한강에서 낙동강 유역으로의 물이동 가능성을 검토하였다. 검토방법으로는 낙동강 유역의 용수부족량을 추정한 뒤 한강 유역에서의 여유량을 모의기법과 최적화기법을 사용하여 추정하였다. 모의기법으로는 HEC-5를 사용하여 중,소규모댐을 검토하고, 최종적으로 동적계획법을 사용하여 다목적댐에 대하여 검토하였다. 또한, 경제적 측면에서 한강-낙동강 유역간 물이동과 낙동강

This study was conducted to evaluate water quality utilizing principal component analysis in the Nakdong River Estuary. From the results of analysis, water quality in the Nakdong River Estuary could be explained up to 65.3 percentage by three factors which were included in river loading(wastes from the Nakdong River and rainfalls ; 39.1%), sediment resuspension(13.7%) and metabolism(12.5%). In the eastern part of estuary in flowing the Nakdong River, river loading factor score(factor 1)was higher than that in western part. Sediment resuspension factor score(factor 2) was high in shallow water, while metabolism factor score(factor 3) was high in deeper water. For seasonal variations of factors score, factor 1 was highly related to rainfall season.

낙동강 유역에서 수질예보시스템의 개발을 위해서 신뢰도해석 기법에 기초한 QUAL2E-AFOSM모형을 개발하였다. 왜관∼물금 구간에 대해 수리학적 부등류 해석을 실시하였고, 최적의 반응계수 추정을 위해 BFGS 기법을 사용하여 최적화 해석을 실시하였으며, 이를 기초로 하여 모형의 보정과 검증을 실시하였다. 추계학적 해석을 위하여 AFSOM 기법을 적용한 신뢰도 해석을 수행하였다. 상류단과 주요 지류에서의 수질, 유량과 반응계수에 대한 변동성을 고려하였다.

수력발전(水力發電)을 위해 배출되는 소양강댐의 냉수(冷水)를 이용한 고추냉이 재배가능성 확인과 적지 선정을 위한 기초자료를 얻고자 강원도 춘천시 소양댐 하류 하천주변과 수원지방에서 1994년 11월 10일부터 1996년 6월까지 약 19개월동안 고추냉이 품종 달마종을 공시하여 재배지의 생육환경과 생육특성 및 수량성, 건물분배율등을 시험한 결과는 다음과 같다. 1. 소양댐의 수질은 수원지방의 지하수보다 인산을 제외한 무기성분함량이 적었으며 용존 산소량과 전기전도도(電氣傳導度)는 재배에 적합한 범위에 있었으나, 수원지방의 지하수는 전기 전도도가 0.45mm hos/cm로 재배 한계치를 넘었으며 용존산소량이 크게 부족하였다. 2. 수원의 지하수는 15.2℃로 비교적 균일한데 비해 소양댐의 물은 연평균 수온이 10.1℃로 계절별 수온의 진폭이 매우컸으며 생육범위의 수온인 8~18℃ 사이에 속한 달은 5~11월이였고 생육억제 수온인 6℃이하의 달은 1~3월이었다. 3. 소양댐의 냉수를 이용하는 경우 육모기간을 포함한 32개월재배로 개체당 주경(主莖)의 근경중(根莖重) 63g이 생산 되었고 상품율(商品率) 80%였으나, 수원지방의 지하수를 이용한 경우 주경(主莖)의 근경중(根莖重) 22g으로 수량(收量)이 극히 적고 상품률(商品率)이 0%였다. 4. 춘천의 소양댐 물을 이용한 경우 수량성은 주근경중(主根莖重) 1099kg/10a, 얼자근경중(蘖子根莖重) 1830kg/10a, 뿌리 1038kg/10a, 엽병(葉柄) 8086kg/10a이었으며 수원의 지하수를 이용하는 경우 주근경중(主根莖重) 343kg/10a, 얼자근경중(蘖子根莖重) 726kg/10a, 뿌리 220kg/10a, 엽병(葉柄) 437kg/10a이었다. 5. 춘천지방에서는 지상부 생육이 왕성하여 엽병중(葉柄重)의 건물분배율(乾物分配率)이 가장 높았으나 수원지방에서는 가장 낮았으며 얼자(蘖子) 발생이 심하여 전한근경중(全根莖重)에서 주한경중(主恨莖重)이 차지하는 비율이 매우 낮았다. 6. 춘천지방의 경우 주근경중(主根莖重)은 초장, 생체중과 유의한 정의상관을 보였고 얼자수(蘖子數)와 부의상관을 보였으며 수원지방의 경우 주한경중(主根莖重)은 근중(根重)과 유의한 정상관을, 전엽수(全葉數), 얼자수와 고도의 유의한 정상관을 보였다.

In order to study on the long-term change of water quality, water analysis was conducted at 16 sites surrounding the Kumho river system for 11 times from September 1990 to August 1993. Analytical items for the study of water quality are as follows; water temperature, pH, COD, BOD, DO, SS, electrical conductivity, NH_3-N, NO_2^- -N, NO_3^- -N, PO_4^3- -P, total-P, hardness, oil and grease, ABS, phenol, zinc, chromium, cadmium, manganese, iron, lead and color. The long-term change of water quality in the Kumho river for the period studied was found that the values of water temperature, electrical conductivity, phenol, NO_2^- -N and NH_3-N were increasing and those of COD, BOD, SS, oil and grease, ABS, NO_3 -N, PO_4^3- -P, copper, zinc, chromium, cadmium, manganese and lead were decreasing, while those of pH, hardness, iron and manganese were steady.

This study was performed to evaluate the contents of heavy metals in water, sediment and soil of the 7 different sampling points along the West Nakdong river. The results were as follows: the concentrations of Zn, P, Pb, Cd, Mn, Cu and As in the sediment were 197.48, 551.85, 67.01, 2.54, 491.39, 42.95 and 10.52ppm,respectively. The concentrations of Zn, F, Pb, Cd, Mn, Cu and As in the soil was 83.32, 482.89, 17.15, 1.02, 226.02, 26.15 and 7.29ppm, respectively, The concentration ratios of heavy metals in the water to the sediment were 593 - 12700 (Cd >> Cu > Zn > Mn > As > Pb) and that of the water to the soil were 152 - 5100 (Cu > Cd > Zn > Mn > As >Pb). The correlation coefficients of Cu and Pb were high among the water, sediment and soil. Because the accumulation amounts of heavy metal in the sediment were high, the concentration of heavy metals in the sediment was higher than in soil. The correlation coefficient of heavy metals among water, sediment and soil was high (0.79 - 0.95).

The COD values and chloride ion concentrations of the Taewha river flowing through Ulsan area were determined along the main stream and the relationships between CODs and chloride ion concentrations were described. The results showed that the middle-upper stream and downstream of the Taewha river were polluted deeply with municipal sewage and self-purification occured in the middle-downstream of the river. When domestic sewage is a main source of pollutants, and is especially the only source of chloride in the stream water, the ratio of COD/[Cl^-] will be utilizable as a measure of self-purification of the stream.