영양염류, 유기물 함량 및 총대장균군에 따른 수질경도 기울기 분석 및 수질매개변수의 상관관계

마문MD ( Md Mamun ),김지윤 ( Ji-yoon Kim ),안광국 ( Kwang-guk An ) 한국환경생태학회 2021 한국환경생태학회 학술대회지 Vol.2021 No.2

In the recent few decades, a lot of environmental ecological pollution and public health issues seem to be connected to poor water quality. The deterioration of water quality is a major concern in the world currently. The Seomjingan River Dam is one of the biggest dams in South korea and it was built for the purpose of preserving the water and reducing floood damages in the areas downstream. The main goal of this research was to decribe the changes in water quality that occur within and after the dam for over a long period, the dataset used was of 10 years (2011-2020). Seasonal analysis of 9 physicochemical water quality variables showed that during the monsoon rain season there was great changes in the water quality variables of which Total Nitrogen (TN), Total Phosphate (TP) and Total Suspended Solids (TSS) were largely influenced to change especially in the inflow site. Inter-annual analysis of 9 water quality variables showed that in between the 10 years indicated that there was decrease of BOD before the reservoir and after the reservoir but it increased within the reservoir. There was high values of TSS, BOD, TP, TN, and TOC in the inlet river site which clarified that the presence of great agricultural and industrial runoff into the river entering the reservoir. This analysis also showed showed that there was decrease of Chl-a throughout the years in the reservoir but there was increase in the washout from the reservoir which indicated that the water that there is primary productivity within the reservoir which affected the water quality. An Empirical analysis also deduced that this reservoir was a P-limited reservoir, and TP had a positive relationship to Chlorophyll-a which means that the TP coming in the reservoir was used for production as it reduced after the reservoir. The trophic State Index analysis for the reservoir indicated that Seomjin dam gets into a eutrophic state during the monsoon perios and this clarifies that there is high nutient runoff into the dam during the monsoon and hence productivity which was indicated by the high CHL-a that is dictated after the dam. In general, from this analysis it can be said that despite the water quality going into the reservoir being bad and that it influenced primary reproduction and sedimentation within the reservoir but due to these processes the water released from the dam seem to be in a better quality than when it entered the reservoir. It is therefore safe to think due to the results found in this study that the reservoir is in a high probability of facing degradation within the next few years.

영산강 수질오염의 시공간적 변화 및 동시다발적 발생 원인분포 분석

마문MD ( Md Mamun ),안광국 ( Kwang-guk An ) 한국환경생태학회 2021 한국환경생태학회 학술대회지 Vol.2021 No.2

Multivariate statistical techniques, such as cluster analysis (CA), discriminant analysis (DA), principal component analysis combined with factor analysis (PCA/FA), and receptor modeling approach like positive matrix factorization (PMF) and water quality index (WQI) were used to assess the spatial and temporal variations of water quality and identify and quantify the potential pollution sources affecting the water quality of the Yeongsan River, South Korea. For this purpose, 15 years dataset of 11 water quality variables covering 16 monitoring sites were used. Nutrients regime (TP, TN), organic matters (BOD, COD), suspended solids (SS), ionic contents (EC), algal growth (CHL-a), and total coliform bacteria (TCB) were affected by the summer monsoon and construction of weirs in the river. CA grouped 16 sampling sites into three clusters, i.e., relatively highly polluted (HP), medium polluted (MP) and less polluted (LP) sites, based on the similarity of water quality features. Stepwise spatial DA identified pH, DO, TN, BOD, COD, CHL-a) and TCB are the parameters responsible for variations among sites, and temporal stepwise DA identified pH, WT, DO, EC, TSS and COD are the parameters responsible for variations among season. The average WQI value ranged from 55 to 141, indicating “poor” to “unsuitable” water quality in the river. Mann-Kendall test showed there was an increasing trend for COD and CHL- a, while it was showing decreasing trend for TP, TN, and BOD. The empirical model suggested that TP (R2=0.37) had a high positive relation with CHL-a than TN (R2=0.25) and TN:TP ratios (R2=0.01), indicating potential P limitations on algal growth in the river. PCA/FA identified three factors in the data structure which explained 85.58% of the total variance of the dataset. PCA/FA was applied to reveal potential pollution sources, while PMF was used to identify their contribution to each water quality variable. Results showed that the domestic and industrial wastewater from two major sewage treatment plants (STPs), agricultural and urban off, and livestock wastewater were the major sources of river water pollution. Our findings may facilitate the management of the Yeongsan River.

다목적 음용수 시설에서의 다변량 기법에 의한 시공간적 계절 수질 평가

우스만아티크 ( Usman Atique ),마문MD ( Md Mamun ),안광국 ( Kwang-guk An ) 한국환경생태학회 2021 한국환경생태학회 학술대회지 Vol.2021 No.2

A long-term water quality evaluation of critical water quality determinants was planned to explore a sustainable water quality supply and management suitability. We analyzed the spatio-seasonal variabilities of ambient nutrients and their enrichment, sestonic chlorophyll-a (CHL-a), the influence of flow regime, and monsoon precipitation through multivariate techniques (PCA, DA) in the second-largest reservoir in South Korea during 2010 -2020. The outcomes sharply defined the maneuvering role of monsoon-mediated flow regime effects on reservoir water chemistry. The reservoir showed a poor to average nutrient condition. An occasional emergence of total coliform bacteria (TCB) of 16000 MPNmL-100 at S3 may break out the waterborne diseases among the children. The Mann-Kendal test exhibited a consistent increase in water temperature (WT), conductivity, and chemical oxygen demand (COD), which may critically endanger a safer drinking water supply. Drought and flood dynamics showed seasonal heterogeneities in CHL-a, TCB, total suspended solids (TSS), and nutrients (N, P). The N:P ambient ratios are a more reliable predictor of sestonic CHL-a productivity, while the reservoir is P-limited. Total phosphorus (TP) showed a strong negative (R2 = 0.59), while TSS (R2 = 0.50) and CHL-a (R2 = 0.32) displayed a strong positive association with reservoir outflow, indicating flow regime impact on enhancing water quality and clarity. Seasonal trophic state index revealed oligo-mesotrophic nutrient enrichment, a good sign for long-term water quality management with limited risk of eutrophication. In conclusion, monsoon arbitrated the flood and drought conditions and disturbed the flow regime influencing the seasonal water quality. Furthermore, increasing intensive crop farming may threaten oligotrophic nutrient enrichment.

하천 어류군집에 기반한 생태학적 건강도 악화를 초래하는 대규모 보 건설의 영향

우스만아티크 ( Usman Atique ),마문MD ( Md Mamun ),남스라이자갈 ( Namsrai Jargal ),안광국 ( Kwang-guk An ) 한국환경생태학회 2021 한국환경생태학회 학술대회지 Vol.2021 No.2

Massive weirs installations in larger rivers could be strongly detrimental to the ecosystem services, water chemistry, and fish assemblages due to unpredicted hydrological modifications and new microhabitat features. This study highlighted the impact of three gigantic weirs erected in Geum River during 2010-2017 compared to the riverine zones from upstream to downstream. Nineteen water quality parameters were studied at 21 sites, while fish assemblages were investigated at 26 sites. The data evaluations included the application of index of biotic integrity (IBI), water pollution index (WPI), and principal component analysis (PCA). The results disclosed seasonal and spatial heterogeneities indicating gradual water quality degradation. TOC, ambient ratios (N:P), Chl-a, and conductivity are dissimilar, while BOD, COD, TSS, TP, and fecal coliforms are directly influenced by seasonal precipitation. Nutrients (N, P) exhibited week relationships in weirs (GW: R2 = 0.21, SW: R2 = 0.12, BW: R2 = 0.25), but stronger in the upstream zone (R2 = 0.74) of the river. WPI, however, designated the weirs and river zones into ‘fair to very poor’ water quality status. Likewise, the ecological health based on IBI specified sites into ‘fair to poor’ health. Overall, 60 fish species and 64637 fish individuals were observed, with 81.24% individuals observed at the weir sites, while Squalidus japonicus coreanus (18.47 % RA) and Hemibarbus labeo (9.25 % RA) were relatively the most abundant fish species sampled. The number of fish species and the total number of individuals gradually declined along the river gradient. PCA grouped the dominant factors in the different zones of the river with a percent cumulative variance 81.80%. The tolerant and omnivorous fish species confirmed aggregations at the downstream zone accompanied by increased insectivorous species. In conclusion, the impacts of weir installation manifested assiduously and indicted increasingly deteriorating water chemistry, gradually declining fish assemblages with jumbled distribution, perturbed microhabitat conditions, and inclusively deteriorating ecological health status.

다목적 저수지 유입 영양염류, Chl-a 상태에 대한 장마기간의 장기적 및 계절 영향 평가

남스라이자갈 ( Namsrai Jargal ),우스만아티크 ( Usman Atique ),마문MD ( Md Mamun ),블랜디나제네스카코레 ( Blandina Genes Kakore ),안광국 ( Kwang-guk An ) 한국환경생태학회 2021 한국환경생태학회 학술대회지 Vol.2021 No.2

Due to rapid eutrophication, sustainable water quality management and supply are essential in drinking water sources and aquatic biota in large reservoirs. We evaluated the potentially crucial factors influencing the algal chlorophyll (Chl-a), nutrients, and the links between the rainfall and other vital elements in a large multipurpose reservoir (Yongdam Reservoir) during 2013-2019. We developed the empirical models on algal Chl-a, total phosphorus (TP), total nitrogen (TN), and TN:TP’s ambient ratios considering the maneuvering influence of Asian monsoons. The intensive rainfall during the monsoon months strongly impacted the nutrient regime and other vital factors. The seasonal patterns of algal Chl-a varied in response to the nutrient contents (TN, TP), suspended solids, and ambient N:P ratios along the longitudinal gradient. The conditional plot analysis, empirical modeling, and observations supported an overall P-limitation scenario, as was evident from the magnitude of N:P ratios (R2 = 0.36, F = 24.9, p < 0.001). Furthermore, the reservoir’s trophic status alluded to the larger particles and blue-green algae during the monsoon and postmonsoon months. The correlation analysis, Mann- Kendall trend test, and principal component analysis illustrated compelling links between CHL-a, TP, and rainfall regime. The outcomes suggested the reservoir was primarily controlled by phosphorus limitation, with an increasing CHL-a tendency along with nitrogen dilution. However, a slight decline in phosphorus was also detected. The Yongdam Reservoir is under the threat of recurrent eutrophication events that could jeopardize this vital drinking water facility due to increasing agricultural and anthropic activities.