• 한국물환경학회지
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• 제26권2호
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• pp.279-288
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• 2010

The water quality variations or changes are closely relevant to the characteristics of unit watersheds and have an effect on the attainment of their water quality goal. This study was conducted to analyze the water quality distribution and its change patterns of unit watersheds in Nakdong river basin. It revealed that 25 unit watersheds out of 41 showed the normality in water quality. Most of unit watersheds had a considerable variation in water quality, especially in the season of spring and summer but a little in terms of flow rate. Annual relative differences in water quality ranged from 13.0 to 26.6% with the maximum of 75%. 28 unit watersheds (62%) had the tendency to decrease in water quality as the flow rate increased while 13 (38%) to increase. The extension of standard flow led to considerable differences in water quality depending on its ranges, which meant uncertainties might be included in the process of TMDL development. It is suggested that annual average flow rate should be chosen as a standard flow in the area where the water quality change has little relation to the flow rate.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1239-1241
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• 2003

This paper presents the results of Landsat-TM imagery applications for detecting spatial variations of the water environments in the Saemankeum (STLR) project areas. The simulated tidal flow patterns from a two -dimensional hydro - dynamic model and water quality data from STRL project were used for relationships with the satellite data. Unsupervised classification of the tidal water body reflects the overall flow patterns at a flooding tide. Regressive equations for water quality parameters were derived and used for supervised classifications. The results were found to be useful to synoptically evaluate the water environments during the construction stages of the STLR project.

• 한국환경과학회지
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• 제21권9호
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• pp.1115-1129
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• 2012

The objective of this study was to analyze long-term annual and seasonal trends of water chemistry on landuse patterns and seasonal precipitation using 72 sampling sites within Namhan River watershed during 2001-2010. Water quality, based on multi-parameters of water temperature(WT), dissolved oxygen(DO), biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(TN), total phosphorus(TP), and electric conductivity(EC) varied largely depending on monsoon rain and landuse patterns such as forest, cropland, and residence. Concentrations of BOD and COD as an indicator for organic matter pollution, increased during summer monsoon season at the cropland and residential streams. Values of TN and TP were higher in residential streams than in the forest and cropland streams. In the meantime, DO values had weak relations to the landuse patterns of forest and cropland cover. Water quality was worst in cropland and residential streams, and also most degradated in 4th order streams. Overall, our results suggest that efficient water quality management is required in the cropland and residential landuse streams.

• Spatial Information Research
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• 제14권2호
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• pp.223-234
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• 2006

연안수질의 시공간적 분포특성을 살펴보기 위하여 1997년부터 2004년 사이에 우리나라 연안해역에서 측정된 수질자료(chlorophyll-a, pH, DO, COD, SS, dissolved inorganic nitrogen, dissolved inorganic phosphorous, salinity, temperature)에 대해 GIS 공간분석 기법을 적용하였다. 본 연구에서 사용된 수질자료는 공간상 모든 위치에 그 값이 존재하나, 실제 간의 수집은 고정관측 위치에서만 수행된다. 따라서 공간적으로 연속적으로 존재하는 연안수질의 분포 특성을 파악하기 위해서는 미관측 지점의 값을 예측할 필요가 있다. 본 논문에서는 공간분석 기법인 IDW를 연안수질 측정자료에 적용하였으며, IDW 기법의 적용 가능성을 평가하였다. 또한 IDW 공간보간을 적용한 후, 전국 연안을 46개 구간으로 구분하여 각 구간의 수질특성을 GIS 시각화 기법을 이용하여 분석하였다. 적용결과 공간보간 및 GIS 기법이 다년간 광범위한 범위에서 수집된 수질 자료로부터 시공간적 분포 특성을 파악하는데 유용함을 확인할 수 있었다.

• 농촌계획
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• 제26권4호
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• pp.53-65
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• 2020

This study aimed to provide a basic information for managing the water quality of national and regional 1st rivers in Gyeongnam by analyzing the emerging hot spot patterns in BOD, T-P, and TOC, and by grouping the changing trends into clusters. The emerging hot spot analysis for each water quality item was implemented in ArcGIS Desktop with monthly water quality data from 96 water environmental monitoring stations in Gyeongnam, and then four patterns of water quality change were classified by the K-mean cluster analysis. As for BOD, persistent cold spot pattern covered about 42.9% of target rivers, and T-P concentration tended to be low or be getting lower at over 70% of target rivers. While, for TOC, about 70% of target rivers resulted in oscillating hot spots. In addition, the cluster analysis showed that the downstream of Nakdong river had the top priority in terms of water quality management because of the increasing concentration for all the three water quality.

• 공학논문집
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• 제8권1호
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• pp.107-118
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• 2006

연안수질 개선 및 환경회복도 추정을 위한 3차원 수질 모델의 구성에서 나타나는 어려운 점들로는 실측자료가 부족하다는 점과 지속적 관측이 어렵다는 점들을 들 수 있다. 따라서, 연안역에 대한 수질모의 및 관리기법 개발 연구의 중간 단계로서 진해-마산만 유역에 대한 강우 및 비점오염물 유출 양상을 실측하였고, 유량 및 오염물 유출양상에 대한 해석을 위하여 위성영상시스템 및 지리정보체계 기법을 적용하였다. 지리정보체계(IDRISI 사용)를 통한 진해-마산만 유역의 용지 사용분포, 지점오염 부하량과 유역정보 결과를 사용하여 수질모의 모형(SWMM 사용)을 적용하였고, 관측되어진 비점오염물들의 유출양상을 통하여 오염물들의 유출특성을 고려한 관측기법의 개선방안과 GIS기법의 적용 방안을 제시하였다.

• 한국물환경학회지
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• 제31권6호
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• pp.723-731
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• 2015

We investigated the spatial and temporal patterns of water quality in the Gangjung-Goryoung weir that is located in the middle area of the Nakdong river, Korea. The monitoring results indicated that there are discernible vertical differences in water quality during the pre- and post-monsoon periods (May to September). During this period, it was observed that the weak thermal stratification formed at the maximum level, and pH, Chl-a, and DO concentrations in the surface layer were higher than those in the bottom layer. This vertical difference was especially noticeable for DO concentrations: there were DO depletions at the bottom layer in late June to early August. During the summer monsoon period with heavy rainfall, there was a decline in vertical differences in water quality. From this study, it was suggested that continuous monitoring of vertical profiles could become a useful tool for identifying the spatial and temporal distributions of water quality and for developing the best management policy for water quality in the Nakdong river.

• 한국물환경학회지
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• 제28권6호
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• pp.819-832
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• 2012

HSPF model based on BASINS was applied for the Hwaseong Reservoir watershed (HRW) to evaluate the feasibility of water quality management. The watershed was divided into 45 sub-basins considering various watershed environment. Streamflow was calibrated based on the measured meteorological data, discharge data of treatment plants and observed streamflow data for 2010 year. Then the model was calibrated against the field measurements of water qualities, including BOD, T-N and T-P. In most cases, there were reasonable agreements between observed and predicted data. The validated model was used to analyze the characterization of pollutant load from study area. As a result, Non-point source pollutant loads during the rainy season was about 66~78% of total loads. In rainy-season, water quality parameters depended on precipitation and pollutant loads patterns, but their concentration were not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. As another result of evaluation for load duration curves, in order to improve water qualities to the satisfactory level, the watershed managements considering both time-variant and pollution sources must be required in the HRW. Overall, it was found that the model could be used conveniently to assess watershed characteristics and pollutant loads in watershed scale.

• 한국환경과학회지
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• 제15권5호
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• pp.447-459
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• 2006

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 duality in the Cheonsu Bay indicated the increase in nutrients and COD concentration.

• 한국물환경학회지
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• 제27권6호
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• pp.794-803
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• 2011

Self Organizing Map (SOM) was applied for pattern classification of hydrological and water quality data measured at Jangseong Reservoir on a monthly basis. The primary objective of the present study is to understand better data characteristics and relationship between the data. For the purpose, two SOMs were configured by a methodologically systematic approach with appropriate methods for data transformation, determination of map size and side lengths of the map. The SOMs constructed at the respective measurement stations for water quality data (JSD1 and JSD2) commonly classified the respective datasets into five clusters by Davies-Bouldin Index (DBI). The trained SOMs were fine-tuned by Ward's method of a hierarchical cluster analysis. On the one hand, the patterns with high values of standardized reference vectors for hydrological variables revealed the high possibility of eutrophication by TN or TP in the reservoir, in general. On the other hand, the clusters with low values of standardized reference vectors for hydrological variables showed the patterns with high COD concentration. In particular, Clsuter1 at JSD1 and Cluster5 at JSD2 represented the worst condition of water quality with high reference vectors for rainfall and storage in the reservoir. Consequently, SOM is applicable to identify the patterns of potential eutrophication in reservoirs according to the better understanding of data characteristics and their relationship.