연안해역의 수질특성 및 일차생산 증가 메커니즘을 이해하는 데에 기초 자료로 활용하기 위하여, 많은 양의 담수 유입 후 규조류가 대량 번식한 상태와 담수가 유입되지 않고 적조가 발생하지 않은 상태의 해수의 수질특성을 조사차였으며 그 결과를 요약하면 아래와 같다. 1) 호우로 많은 양의 담수가 유입된 해역에서 규조류인 Skeletonema costatum와 Thalassiosira spp.가 각각 1,200~5,000cells/mL, 750~1,200cells/mL의 농도로 관찰되었다. 2) 규조류가 대량으로 증식하지 않은 곳보다 규조류가 대량으로 증식한 곳에서 수온, PH, 용존산소농도가 높게 조사되어, 두 곳 사이의 거리가 20m 정도에 불과함에도 불구하고 두 곳의 수질특성 차이는 뚜렷하게 나타났다. 3) 규조류가 대량으로 증식하지 않은 곳보다 규조류가 대량으로 증식한 곳에서 질소 인, 규소의 농도가 낮게 조사되어, 호우로 질소, 인, 규소보다는 규조류가 증식하기 위해 필요한 미량원소가 육지로부터 풍부하게 유입된 것으로 보인다. DIN/DIP, DIN/SiO2-Si 비는 모두 규조류가 대량 증식한 정점과 그렇지 않은 정점간의 뚜렷한 차이는 없었다.

목포항 주변 해역의 6개 정점에서 1997년부터 2004년까지 수질의 계절 및 년간 변동에 대해 조사하였다. 염분, pH, 용존무기질소와 용존무기인은 년간 다양하게 나타났다. 염분은 1998년에 유의하게 나타났으나, 영양염 농도들은 1998년이 다른 년도보다 유의하게 높았다. 수온, DO, COD와 DIP의 농도는 계절 변동이 명확하게 나타났으며, 이러한 계절적인 변화는 영산강하구언에서 유입되는 담수의 계절적인 특징에 영향을 받았다. 수온, COD와 DIP는 8월에 유의하게 높았으나, 염분과 DO는 8월에 최소로 나타났다. 정점 1(영산강 하구언)의 수질은 영산강의 유입에 따른 낮은 염분과 높은 영양염의 특성을 보였으나, 정점 6(목포항 외해)은 주로의 외해의 특성을 보였다. 목포항 주변 해역에서 수질 인자간의 관계에서 염분은 COD, DO, pH, Chlorophyll a와 영양염 농도에 주요한 요인으로 나타났다.

1998년에서 2000년까지 2월과 5월, 8월, 11월 각 분기별로 영일만과 형산강의 수질의 변화에 대하여 조사하였다. 그리고 형산강에서 영일만으로 유입되는 담수가 영일만 수질에 미치는 영향에 대하여 고찰하였다. 수온은 5월과 8월에 높은 기온과 냉수대의 영향으로 표층수는 저층수보다 수온이 높으며, 염분은 형산강으로 부터 유입되는 담수의 영향으로 만 내측이 특히 낮은 특징을 나타내었다. 그리고 표ㆍ저층수의 염분차는 만 외측이나 만 중앙부에 비하여 만

시아해의 수질환경과 식물플랑크톤 생물량의 계절변동 특성 및 식물플랑크톤 생물량변동에 영향을 미치는 환경요인을 파악하기 위해 1995년 2월,4월,7월과 10월 4회에 걸쳐 계절별로 23개 관측점의 표층과 저층 해수를 대상으로 현장조사를 실시하였다. 결과, 시아해는 2월에 최저수온, 8월에 최고 수온을 나타내나, 염분은 6, 7월에 높고 겨울에 낮은 특성을 나타내었으며, 연중 빠른 유속과 조석혼합 등으로 수층 간 혼합된 양상과 매우 낮은 투명도를 나타내고

In this study, water quality levels were classified and water quality indices were calculated and analysed by using the water quality components of living environmental standards monitored 10 years (2008 ~ 2017) at four stations in the West Nakdong River. As a result of analyzing the monthly variation of the water quality components of the living environmental standards, the water quality in the West Nakdong River was worse downstream than upstream, and pollution at the WNR3 located in the downstream of the Jomangang was the most serious. As a result of classification of water quality levels, BOD and COD levels were the lowest, so water quality pollution in the West Nakdong River was found to be highly influenced by organic matters. The water quality index was the lowest in July and August at four stations, so water quality is showing the worst in summer. As a result of analyzing the correlation between the water quality components and the water quality index, the correlation between the TOC and the water quality index was high in the four stations, and the water quality index in the West Nakdong River was dominated by organic matters and nutrients.

Statistical analysis was carried out to identify the influence on environmental factors between paddy water chemical properties and Chl-a concentration (algae biomass index) using water samples collected in June for 3 years at rice paddy field. As a result of correlation analysis, there was a significantly negative relationships in DO(-0.366) and pH(-0.141). In contrast, significantly positive relationships were founded in COD(+0.431) and TOC(+0.422). According to the result of factor analysis, 3 factors were obtained and indicated that PC1 were Ca, K, Mg cation, PC2 were TOC, T-P, PO4 3--P and DO, and PC3 were T-N and NH4 +-N. As a result of linear regression analysis to develop a prediction model for chl-a concentration, the total amount of explanation was 20.6%, PC2 had the greatest influence on the increase of chl-a concentration and PC1 also showed a positive correlation but the PC3 has a negative correlation. In conclusion, carbon and phosporous content are the main factors for the increase algae blooms of rice paddy.

계절별 유량의 연간 변동성은 열대지역의 해수면 온도와 같은 기후요소들을 사용하여 예측될수 있으며, 일 유출량의 변동성은 기상요소들을 사용하여 예측할 수 있다. 또한, 유출량은 하천에서 비점오염원으로부터의 오염물질 부하량과 밀접한 관계를 가진다. 이러한 관계에 기초하여, 이 연구에서는 기후 및 기상 예측 값들을 활용하여 계절별 그리고 일별 영양물질 부하량을 예측한다. 영양물질으로는 총질소(TN)의 부하량을 예측하였으며, 미국 동남부 지역에 위치한 18개 관측 지점을 대상으로 하였다. 계절별 영양물질 부하량 예측을 위해서는, 우선 기후 예측값을 사용하여 계절별 유출량을 모의하고, 모의된 유출량값들을 사용하여 다시 영양물질 부하량을 예측 하였다. 이를 위해 겨울동안의 계절별 영양물질 부하량을 예측하기 위해 개발된 로그-선형 주성분 회귀분석 모형은 예측 강우량과 관측 강우량 사이의 유의한 관계를 나타내었으며, 예측 강우량을 사용하여 유출량을 성공적으로 예측할 수 있었다. 일 영양물질 예측을 위해서는 기상조건을 대표하는 일일 선행 강우 예측값과, 초기 유역 조건을 대표하는 과거 3일의 일유량 평균값을 두개의 예측치로 사용였으며, 모형으로는 비모수 재표본 방법을 사용하였다. 이상으로부터 예측 모의된 계절 그리고 일 영양물질 부하량은 해당 유역에서의 기준 영양물질 부하량을 초과하지 않도록 하는 영양물질 배분 모형에 활용될 수 있으며, 수질 관리 계획을 위한 영양물질 배분 모형의 잠재적 유용성에 대해서 논의 하였다.

This study presented seasonal changes of the phytoplankton community in Junam reservoir by pollution and water quality of the lake. The water storage of the reservoir is 5.3 million ton, most of which are being utilized for agricultural, industrial and residential purposes. The annual precipitation during the investigation period was 1,868.9 ㎜, increasing by 20% from the average annual level of 1,506.7 ㎜ in 2009. The annual average water storage was 57.3%. It decreased during agricultural season and then increased again after monsoon rainfall. The loads of BOD were 3,799 ㎏day -1 , and 81% of them came from livestock and household. The TN and TP loads were 1,164 ㎏day -1 and 170 ㎏day -1 , respectively, and 76% of them came from livestock. We assessed water quality of the Junam reservoir using 17 variables. According to the result, the reservoir met the fourth grade, meaning slightly bad, because of high concentration of COD, SS and chlorophyll-a. Eutrophication assessment was conducted by revised Carlson's Index (TSIm, Aizaki), and it was found that the entire lake was eutrophicated with high chlorophyll-a concentration all through the year, except during February to April and in July. A total of 76 phytoplankton species were identified from the samples. Among them, the largest number of species were Chlorophyceae with 33 species(43.4%), followed by Bacilliophyceae with 27 species(35.5%), Cyanophyceae with 8 species(10.5%), and Cryptophyceae with species(10.5%). The total cell number of phytoplankton was the highest in October(7,884 cells mL -1 ) among Cyanophyceae and Bacilliophyceae. The seasonal succession of Chlorophyceae (Chlamydomonas spp.), Cyanophyceae(Microcystis aeruginosa) and Cryptophyceae(Rhodomonas spp.) was observed during January to May, July to September and October to December respectively.

This study was carried out to determine marine environments and phytoplankton community around Mokpo harbour on March to November during the period of 2004-2009. The remarkable fluctuations of marine environments were shown around Mokpo harbour depending on monthly and yearly. Among seasons, summer was a great that was associated with extremely releasing the freshwater from Youngsan River Weir, contributing to effect the fluctuations of water quality. Nevertheless of monthly and yearly, the molecular ratio of N:P was always shown in above 16 that was mainly attributed to freshwater discharge on March to November. This indicates that phosphorus playes an important role in limiting factor as growth in phytoplankton. During this study, Skeletonema costatum was found to be richer than the other groups of diatoms in terms of abundance and species number. Mokpo harbour, with the presence of a narrow avenue for exchange with offshore waters, has limited growth in phytoplankton, but this species is able to well adapt and fast grow under even high level of suspended solid and low intensity of light compared with other species. The discharge of freshwater is associated with significantly fluctuation of marine environments in this region, but it does not affect the quantitative and qualitative distribution of phytoplankton. It is necessary to persistently monitor based on water quality and phytoplankton community.

Long-term trends and distribution patterns of water quality were investigated in the Asan coastal areas of Yellow Sea, Korea from 1975 to 2005. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO) and nutrients. Spatial distribution patterns were not clear among stations but the seasonal variations were distinct except COD, SS and nitrate. The trend analysis by principal component analysis (PCA) during twenty years revealed the significant variations in water quality in the study area. Annual water qualities were clearly discriminated into 4 clusters by PCA; year cluster 1988-1991, 1994-1997, and 1992-1993/1998- 2005. By this multi-variate analysis we can summarize the annual trends as the followings; salinity, suspended solids and dissolved oxygen tended to increase from late 1980's, increased pH and COD from 1992, and decreased salinity and increased nitrogen and COD from 1990 due to the runoff frow agricultural lands causing eutrophication.

Long-term trends and distribution patterns of water quality were investigated in the Cheonsu Bay of Korea from 1983 to 2004. Water samples were collected at 4 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO) and nutrients. Spatial distribution patterns were not clear between stations but the seasonal variations were distinctive except COD, SS and nitrate. Twenty two year long-term trend analysis by PCA revealed the significant changes in water quality in the study area. Water quality during 1980's and early 1990's showed high SS, low nutrients and low COD which increased during the mid and late 1990's and early 2000's. Overall water quality in the Cheonsu Bay indicated the increase in nutrients and COD concentration.

In order to study on the variational characteristics of water quality and chlorophyll a concentration, the water samples were collected daily or three times a week during the period from April 1990 to November 1991 at Kukdong port located in the Northern Kamak bay of Southern Korea I made an analysis on biological factor as chlorophyll a concentration as well as physico-chemical factors such as water temperature, salinity, sigma-t, dissolved oxygen, nutrients (ammonia, nitrite, nitrate, phosphate, and silicate), N/P ratio and chemical oxygen demand. In Northern Kamak bay seasonal variations in physical factors such as water temperature, salinity and sigma-t were very marked. On the other hand, chemical factors such as nutrients concentration and COD were not so. Chemical factors, in particular, silicate were influenced by input of freshwater. And the roles of silicate on the seasonal succession of phytoplankton species composition was very low. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round, and it was controlled by the combination of several factors, especially of N/P ratio determined by dissolved inorganic nitrogen.

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 community of phytoplankton and water quality were investigated 5 times from October, 1994 to October, 1995 in the east area of Chinhae Bay. Seasonal changes of environmental parameters were shown general pattern and related to the red tide mechanism of phytoplankton community. Seasonal variations of dissolved oxygen concentrations were affected by the photosynthetic activity of phytoplankton community and the increase of COD at the bottom water was occurred after the red tide. The standing stocks of phytoplankton in this study area ranged 202 - 1616 Cells·ml^-1 and the bloom(red tide) was formed from April to July. The diatom species, Skeletonema costatum was a dominant species all the year round and the dinoflagellate species, Alexandrium tamarense and Prorocentrum triestinum were red tide species increased standing stocks in phytoplankton bloom.

This study was performed to analyze the variation characteristics of water qulity, correlation analysis of water quality data at each site and among the items of water quality data. Water quality for analysis was monthly values of water temperature, pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, suspended solid, T-N and T-P checked in Daecheong Lake from January to December, 1995. It was analyzed variation of monthly water qulity was well from February to April, water temperature and COD seemed to have high correlationships at all sites. Regression equation is COD = 0.07 Water temperature + 1.23 (R^2 = 0.7616) . Results of the correlation analysis of water quality data showed that DO had higt correlationships between site 1 and site 2, BOD did site 1 and 3, COD did site 1 and 2, SS did site 5 and 6, T-N did 2 and 3, T-P did site 4 and 6. Regression equations for estimate of water quality data are as follows. DO_1 = 4.46 + 0.59 DO_2 (R^2 = 0.8868), BOD_1 = 0.52 + 0.63 BOD_3 (R^2 = 0.6390) COD_2 = 0.44 + 0.71 COD_1 (R^2 = 0.9183), SS_6 = 0.89 + 0.70 SS_5 (R^2 = 0.9155) TN_3 = 0.151 + 0.886 TN_2 (R^2 = 0.9415), TP_4 = 0.004 + 0.758 TP_6 (R^2 = 0.9669)

A study was carried out on the distribution of chlorophyll a and water quality in the dry season in Yosuhae bay and adjoining sea, Southern Korea, in July of 1994. Concentration of salinity and phosphate were lower in the outer bay than in the inner bay. While nitrate and silicate were higher in the former than in the latter. We were identified with coastal water of origin from China with the lower salinity in outer bay. The China coastal water was characteristic of high nutrients and phytoplankton biomass, such as chlorophyll a. The principal component analysis (PCA) on the analytical data proved that high density of phytoplankton biomass occurred under the condition of low salinity and high concentration of dissolved inorganic nutrients. It is thought that the thermoharine structure and biological produtions of Yosuhae bay were controlled by the China coastal water in the outer bay.