• 생태와환경
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• 제39권2호통권116호
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• pp.236-244
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• 2006

경안천 유입부(G 1)부터 팔당댐 앞 (P)까지의 2002년도 수질변동을 팔당호 전체 수질분포및 강우시기 등과 연동하여 평가하였다. 연평균 COD, 총인 및 총질소 농도는 경안천 유입부에서 댐 쪽으로 갈수록 농도가 크게 낮아지는 것으로 나타나, 경안천 유입하천의 높은 오염도가 직접 댐 앞 수질에 미치는 영향은 크지 않은 것으로 판단되었다. 조사시기 및 지점별 COD, 총인 및 총질소 농도는 강우기 (8, 9월)가 다른 조사시기에 비해 지점 간 차이가 적고, 초기농도도 상대적으로 낮았다. 클로로필 a 농도는 강우기 이후(10 ${\sim}$ 12월)보다는 이전(3${\sim}$6월)에 각 지점별 농도차이가 큰 것으로 나타났다. 팔당호 전체 수질분포에서, 북한강 유입수역 수온은 다른 수역에 비해 8월은 낮고 11월에는 높게 나타났다. COD와 SS농도는 강우기에는 각 수역별로 비교적 큰 농도차이를 보였으나 11월에는 큰 차이를 보이지 않았고, 농도도 낮았다. 4월 높았던 클로로필 a 농도는 강우기에는 현저하게 낮은 농도를 보였다. 4월에는 비교적 수심이 낮은 경안천 유입수역에서도 8월 및 11월에 비해 표층과 심층간의 수온 차가 크게 나타났다. 댐 앞 지점 SS농도는 4월에 표층에서 높고 8월에는 심층에서 높았다. 또한 COD, 총인, 총질소 농도는 8월이 4월에 비해 상 ${\cdot}$ 하층이 비교적 잘 혼합되고, 현저하게 낮은 농도를 보였으며, 11월에도 낮은 농도를 유지하고 있는 것으로 볼 때, 팔당호에서 수질관리에 집중해야 될 시기는 여름가을보다는 봄여름기간 중인 것으로 판단되었다.

• 한국물환경학회지
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• 제20권6호
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• pp.698-702
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• 2004

At five stations in Gyeongan River, a tributary of Lake Paldang, physicochemical and biological environmental factors of water, particulate matters, and sediments were investigated biweekly from April 11 to December 22 in 2001. The studied area was characterized as a stream-lake system. The system is primarily referred to a place where the environmental factors had considerably changed depending on the amount of precipitation. As a result, the river turned out to be strongly eutrophicated. Also, some characteristics of the water and the particulate matters at midstream such as average concentrations of conductivity, nutrients, and chlorophyll $\alpha$ were higher than the characteristics of up and down-stream. However, the concentrations of organic matters and ratio of clay and silt of the midstream were determined to be higher than up and down-stream sediments. As the result of the factor analysis, 4 major different patterns for environmental factors are found from samples of water, particulate matters, and sediments.

• 한국습지학회지
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• 제14권4호
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• pp.561-569
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• 2012

본 연구에서는 경안천 유역을 대상으로 1975년부터 2000년까지의 토지피복상태에 따른 불투수면과 투수면을 재분류하여 경관분석 프로그램을 이용하여 경관 지수를 산정하였다. 경관 지수 중 총 중심지면적인 TCA(Total Core Area)를 생물종 다양성 지표로 이용하였다. 선정된 경관 지표 TCA와 불투수면 모델인 ICM(Impervious Cover Model)을 이용하여 실제 경안천 유역의 어류 출현종수와 비교하였다. TCA와 불투수면 비율의 관계에서는 불투수면 비율 증가에 따라 TCA값이 점차 감소하는 추세를 보였다. 이는 도시화와 인위적인 개발로 인해 경관에서 불투수면 면적이 차지하는 비율이 커지면서 생물종이 외부로부터의 격리를 필요로 하는 임계면적이 점차 감소하였음을 나타낸다. 또한, 경안천에 서식하는 출현 어류종의 종류를 모니터링 해 본 결과 불투수면 비율이 낮은 지역에서 청정수에 서식하는 종의 출현빈도가 높음을 알 수 있었다. 경안천 유역은 하천상태가 Impacted Stream(손상하천) 위에 해당하여 유역의 상태가 나빠지는 단계에 있는 것으로 파악되었으며, 이 구간에서 유역은 불투수면 비율에 민감하게 반응하므로, 계속적으로 집중적인 유역관리가 필요하며, 지역에 출현하는 어류다양성을 증가시키기 위해 유역상태를 개선시킬 필요성이 있다.

• 한국물환경학회지
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• 제26권1호
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• pp.71-80
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• 2010

We studied the nitrogen behavior and budget of Lake Paldang from March to December 2008. The particulate nitrogen (PN) concentrations ranged from 7 to 13% of the total nitrogen concentration (TN) in the stream inflows, the downstream outflow, and the lake water. The nitrate nitrogen ($NO_3-N$) concentration ranged from 67 to 78% of the TN. In the three rivers of Lake Paldang, Gyeongan River (In3 site) had the highest average of the TN, 5.037 mgN/L, but North Han River (In2 site) had the lowest average TN, 1.683 mgN/L. South Han River (In1 site) had the average TN of 2.399 mgN/L. In the dam discharge, TN showed the average 2.063 mgN/L. In the lake water, L4 site (Gyeongan River area) had the highest average TN, 3.781 mgN/L, but L3 site (North Han River) had the lowest average TN, 1.587 mgN/L. Total input of nitrogen loads to Lake Paldang was about 30,875 ton/year in 2008. Inflow rivers contributed 30,643 ton/year (South Han River: 18,111 ton/year (59%), North Han River: 11,333 ton/year (37%), and Gyeongan River: 1,199 ton/year (4%)). The atmospheric deposition had 135 ton/year, the nitrogen release from the bottom sediments had 88 ton/year, and macrophytes had 9 ton/year. Total output of nitrogen loads from Lake Paldang was about 31,256 ton/year. The downstream from dam contributed 29,877 ton/year, and the sediment deposition was 1,379 ton/year.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.566-569
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• 2004

This study is to trace the change of stream shape using the past series of aerial photographs, and to compare the land use changes of riparian area along the stream. For the Gyeongan national stream, aerial photographs of 1966, 1981 and 2000 were selected and ortho photographs were made with interior orientation and exterior orientation, respectively. As apparent changes of the stream, the consolidated reaches of stream with levee construction were straightened and their stream widths were widened. Especially the stream width of inlet part of Paldang lake was widened almost twice because of the rise of water level by dam construction in 1974. The land use maps (1966, 1981,2000) of riparian areas were also made, respectively and classified into 6 categories (water, forest, agricultural land, urban area, road, sandbar) by digitizing. The area of forest and agricultural land decreased and urban area increased as the stream maintenance was performed.

• 한국농공학회논문집
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• 제47권2호
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• pp.15-21
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• 2005

This study is to trace the change of stream shape using the past series of aerial photographs, and to compare the land use changes of riparian area along the stream. For the Gyeongan national stream, aerial photographs of 1966, 1981 and 2000 were selected and ortho-photographs were made with interior orientation and exterior orientation, respectively. Apparent changes of the stream were found that the consolidated reaches of stream by levee construction became straight together with widening of their stream widths. Especially the stream width of inlet part of Paldang lake widened almost twice because of the rise of water level by dam construction in 1974. The land use of riparian areas of three selected years were classified into six categories (water, forest, agricultural land, urban area, road, sandbar) by digitizing method. The forest and agricultural lands decreased and urban area increased as the stream maintenance had been performed.

• 한국수자원학회논문집
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• 제38권5호
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• pp.379-390
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• 2005

본 연구에서는 경안천 유역을 대상으로 과거의 경년 항공사진과 지형도를 이용하여 하천형태의 변화를 분석하고, 하천주위의 토지이용변화를 비교해 보고자 하였다. 이를 위해 경안천 유역의 지방 1, 2급 하천에 해당하는 1966년, 1981년, 2000년 항공사진에 내, 외부표정을 실시하여 정사영상을 생성하였으며 또한 1914 - 1915년 지형도를 이용하여 1966년, 1981년, 2000년의 하천과 비교하였다. 이 영상을 이용하여 경년 하천형태와 하천부지의 토지이용을 분석하였는바, 주로 하천제방구역에서 뚜렷한 하천변화를 보였으며 이는 1974년의 팔당댐 건설에 따른 팔당호 유입부의 변화와 1980년대 후반의 하천정비에 따른 직선화 작업이 그 원인으로 판단된다. 또한 하천부지를 6개의 주요 분류 항목 (수역, 산림, 농지, 주거지, 도로, 모래톱)으로 토지이용도를 작성하여 그 면적변화를 분석해본 결과 농지, 주거지, 도로, 모래톱이 가장 큰 면적변화를 나타내었다.

• 한국물환경학회지
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• 제24권6호
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• pp.750-757
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• 2008

This study is conducted to characterize and evaluate delivered pollutant loads of point and nonpoint source on the upper watershed of lake paldang. The study area consists of 12 watersheds in Namhan-river and Kyungahcheon, which are approximately 80% of total area of Namhan-river and Kyungahcheon. Based on daily delivered loads from watersheds, 61% of $BOD_5$, 81% of T-N and 70% of T-P were from nonpoint sources, suggesting that delivered loads of nonpoint pollutants be crucial to water quality. On the other hand, 78% of $BOD_5$, 92% of T-N and 87% of T-P as delivered load were from nonpoint sources in an upper watershed of Namhan-river, while 48% of $BOD_5$, 70% of T-N and 57% of T-P as delivered load were from nonpoint sources in a lower watershed of Namhan-river, suggesting higher dependency of point sources than upper watershed of Namhan-river. In the characteristic of delivered loading pollutants from point and nonpoint pollution sources, delivered load of nonpoint pollutants differed significantly by seasonal flow, and as though discharged load of point pollutants were yearly uniform, delivered load of point pollutants was found to be flow-dependent because its delivery ratio was changed.

• 한국농공학회논문집
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• 제54권4호
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• pp.9-17
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• 2012

This study was aimed to characterize non-point source (NPS) pollutant runoff and estimate event mean concentrations (EMCs) from a small rural watershed located at the headwater area of the Gyeongan stream. The study watershed consists of the two major landuse, forest (72 %) and paddy field (28 %). The nine rainfall events ranging from 18.5 to 192.6 mm in amount were monitored in this study. Stream flow was measured at the watershed outlet using a water level gauge, while a number of water samples for each event were collected and analysed for water quality. Event pollutant loads varied greatly depending on rainfall events varying from 22.6 to 3,134.2 mg/L, 0.32 to 24.56 mg/L, 0.090 to 1.320 mg/L, and 2.3 to 149.8 mg/L for SS, TN, TP, and COD, correspondently. The respective mean EMCs were estimated by 104.2, 1.00, 0.168, and 7.9 mg/L. The Pearson correlation analysis showed that COD EMC was significantly correlated with those of SS, TN, and TP. Rainfall runoff ratio appeared to be negatively correlated with EMCs of SS, TP, and COD, although not statistically significant. The event loads from the largest rainfall was greater than the sum of those from the remaining eight events. The study results suggest that the appropriate management of intensified storm events are of greater importance in curbing NPS loads, while the estimated EMCs provide base data for the unit pollutant loads determination for the forest-paddy composite upstream watershed.

• 한국물환경학회지
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• 제25권6호
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• pp.951-963
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• 2009

The community structure and ecological characteristics of fish community in Lake Paldang were investigated from May to September 2008. During the survey period, 53 species belonging to 13 families were collected. Dominant species was Squalidus japonicus coreanus representing 81.8% of total number and 25.7% of total biomass of collected fish and subdominant species was Lepomis macrochirus representing 3.3% of total number and 18.9% of total biomass of collected fish. There were 20 Korean endemic species (38% of collected species number) including Cottus koreanus and 4 exotic species (7.5%) including Micropterus salmoides. The similarity analysis of fish communities among water areas of Lake Paldang using UPGMA showed that fish community of North-Han River was similar to that of South-Han River area and was different from that of Gyeongan River area. Long-term variation of fish community from 1972 to present study in Lake Paldang showed decrease of the species numbers after dam construction until 1994, and gradual increase from 1996 to present study indicating the disturbance of lentic system by dam construction in the 1980s. The increase of species number in the late 2000s may results in part from the increase of survey sites of successive studies. L. macrochirus which was designated as a domestic ecosystem-disturbing alien species with wide food niche have shown more than 20% of relative abundance since 1996 indicating the adverse effect on not only fish community but also aquatic ecosystem food web of Lake Paldang.