• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.475-475
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• 2022

The aim of this study is to identify the significant pollutant sources from the tributaries that are affecting the water quality of the study site, the Geum River and provide a solution to enhance the water quality. Multivariate statistical analysis modles such as cluster analysis, Principal component analysis (PCA) and positive matrix factorization (PMF) were applied to identify and prioritize the major pollutant sources of the two major tributaries, Gab-cheon and Miho-cheon, of the Geum River. PCA identifies three major pollutant sources for Gab-cheon and Miho-cheon, respectively. For Gab-cheon, wastewater treatment plant (WWTP), urban, and agricultural pollutions are identified as major pollutant sources. For Miho-cheon, agricultural, urban, and forest land are identified as major pollutant sources. On the contrary, PMF identifies three pollutant sources in Gab-cheon, same as PCA result and two pollutant sources in Miho-cheon. Water quality control scenarios are formulated and improvement of water quality in the river locations are simulated and analyzed with the Environmental Fluid Dynamic Code (EFDC) model. Scenario results were evaluated using a water quality index developed by Canadian Council of Ministers of the Environment. PCA and PMF appears to be effective to identify water pollution sources for the Geum river and also its tributaries in detail and thus can be used for the development of water quality improvement alternative of the above water bodies.

• 한국농공학회논문집
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• 제66권4호
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• pp.51-57
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• 2024

This study was conducted on how to simulate runoff, which was done using existing physical models, using an LSTM (Long Short-Term Memory) model based on deep learning. Tancheon, the first tributary of the Han River, was selected as the target area for the model application. To apply the model, one water level observatory and four rainfall observatories were selected, and hourly data from 2020 to 2023 were collected to apply the model. River water level of the outlet of the Tancheon basin was simulated by inputting precipitation data from four rainfall observation stations in the basin and average preceding 72-hour precipitation data for each hour. As a result of water level simulation using 2021 to 2023 data for learning and testing with 2020 data, it was confirmed that reliable simulation results were produced through appropriate learning steps, reaching a certain mean absolute error in a short period time. Despite the short data period, it was found that the mean absolute percentage error was 0.5544~0.6226%, showing an accuracy of over 99.4%. As a result of comparing the simulated and observed values of the rapidly changing river water level during a specific heavy rain period, the coefficient of determination was found to be 0.9754 and 0.9884. It was determined that the performance of LSTM, which aims to simulate river water levels, could be improved by including preceding precipitation in the input data and using precipitation data from various rainfall observation stations within the basin.

• 한국환경농학회지
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• 제24권4호
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• pp.319-325
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• 2005

만경강과 동진강 하천토사의 이화학전 특성과 형태별 인 함량을 조사한 결과 하천토사의 총인 함량은 만경강에서 $290.1{\sim}405.4mg/kg$ 수준으로 평균 363.4 mg/kg을, 동진강에서는 $304.1{\sim}431.7mg/kg$ 수준으로 평균 353.6 mg/kg을 나타냈고 조사지점 모두 6월과 3월에 높은 농도를 나타내었다. 이는 높은 농도의 질소와 인을 함유하고 있는 농경지 표토층이 강우-유출에 의해 하천에 유입되어 영향을 받았기 때문인 것으로 추정된다. 하천토사 내 인의 형태별 함량을 조사한 결과 만경강과 동진강에서 각 각 인회석태 인 52.1%와 42.7%, 유기태 인 27.3%와 34.2%, 비인회석태 인 18.1%와 22.5% 그리고 흡착태 인은 두 지역 모두 0.6%를 나타내었다. 하천토사 중 흡착내 인은 그 양이 매우 적어 수중생태계에 끼치는 영향이 미미할 것으로 판단되나, 비인회석태 인은 혐기성 상태가 되거나 pH가 높아지면 용출이 일어날 것으로 사료되어 관리가 필요할 것으로 나타났다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1003-1012
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• 1993

The objective of this study was to evaluate the effectiveness of tillage and cropping management systems in reducing the movement of nitrate and pesticides in surface and sub-surface flow. Nitrate and pesticides in runoff and sub-surface tile flow have been monitored for two years from fields with various tillage and cropping management practices. Samples have also been obtained along the mainstream of the watershed. Concentrations of nitrate an pesticides differed little among specific sampling locations along the river, but they definitely followed a seasonal cycle. Nitrate concentrations from the tile drains varied considerably between fields depending upon the cropping management systems used, with concentrations varying seasonally as inthe river.

• Current Research on Agriculture and Life Sciences
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• 제17권
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• pp.31-38
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• 1999

3차 국토종합개발 10개년 계획기간 (1992-2001) 가운데 1994년~1998년은 에리뇨와 라니냐 등 해수온도의 상승 및 하강 현상에 의한 게릴라성 폭우등 이상기후현상이 뚜렷한 해로 평가하고 있다. 이 기간에 대한 한강, 낙동강, 금강, 영산강 그리고 섬진강의 한국 5대강수계에 대한 강수량, 유출량 및 저수량을 도출하고 전국 평균 (1961년~1990년)의 해당 수문량과의 비교분석을 시행하여 그 결과를 5대강 수계의 수자원관리 및 방재수립에 참고 하고져 조사 분석한바 5 대강 수계의 표본기간 (1994~1998, 48개월) 평균 강수월수가 예년평균 동기간에 비하여 많았던 기간은 20개월 이었고, 유출은 평균 8.2개월에 이른다. 한편 댐 저수율은 한강수계의 경우 비교적 많은 량으로 이상적인 현상을 보인 반면, 낙동강수계는 초기에는 낮은 저수율이고 후기에는 높은 저수율 현상 이었고, 금강, 영산강 및 섬진강은 초기부터 후기로 점증 하는 경향으로 나타나 유역적인 편차현상이 크게 나타나 수자원의 관리와 방재계획을 수계의 연결 및 호환적 종합 운영등의 방식이 검토되어야 할것으로 생각된다.

• 한국환경농학회지
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• 제23권2호
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• pp.81-84
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• 2004

새만금 유역의 수질관리를 위한 기초자료 확보를 목적으로 만경강 및 동진강 유역의 개황과 각 하천 본류의 수질에 미치는 지천들의 영향을 평가하기 위하여 2001년 6월부터 2002년 9월까지 동절기를 제외한 영농 기간동안 매월 1회 주요 지천들의 본류 유입 전 후의 BOD 변화를 조사한 하였다. 만경강 수계는 미처리된 축산폐수로 오염된 익산천 유입 후 BOD가 증가하였으며, 전 조사 기간동안 평균 5.4 mg/L이었다. 만경강 수질에 큰 영향을 주는 익산천은 왕궁천과 합류되기까지 평균 BOD는 5.4 mg/L로 만경강 본류의 평균 농도와 같은 수질을 보였으나 인근 축산단지로 부터의 축산폐수 유입으로 익산천 하류의 BOD는 평균 13.6 mg/L로 수질이 악화되었다. 동진강 수계는 조사기간 동안 평균 BOD가 2.8 mg/L로 만경강 보다 양호한 수질을 보였으며, 생활하수 및 공장폐수로 오염된 정읍천 유입으로 동진강 하류의 수질은 평균치 보다 다소 높은 3.5 mg/L을 나타냈다. 또한, 만경강 및 동진강 수계의 연차별 수질은 2001년도에 비해 2002년도에 BOD가 다소 낮은 경향을 보였다.

• 한국환경농학회지
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• 제18권2호
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• pp.122-125
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• 1999

The water quality of the Keum river was surveyed at 4 sites from April to September in 1995 and 1997. Average values of inorganic contents analyzed in 1997 were pH 7.2, EC 0.18dS/m, $NH_4-N$ 0.60mg/l, $K^+$ 4.12mg/l, $Ca^{2+}$ 12.12 mg/l, $Mg^{2+}$ 2.75mg/l, $Na^+$ 15.1mg/l, $NO_3-N$ 1.97mg/l, $PO_4^{3-}$ 0.15mg/l, $PO_4^-$ 18.9mg/l, $Cl^-$ 21.8mg/l, Fe 0.22mg/l, COD 19.7mg/l. On the basis of these values, it was suitable for the irrigation source. Water pH of the Keum river ranged from 6.7 to 8.0. EC of the Daecheong-dam was maintained below 0.13dS/m, but those of the middle and lower stream were ranged from 0.13dS/m to 0.32dS/m. Monthly average values of all the ration contents were the highest in April and were decreased thereafter. And it was slightly increased in September. However $NO_3-N$, $SO_4^{2-}$ contents were higher in June than any other months. All the inorganic contents were the highest at Taepyeong-ri, Yeongi-gun due to sewage water and livestock wastes. The inorganic contents were negatively correlated with precipitation, generally.

• 한국약용작물학회지
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• 제9권1호
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• pp.76-82
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• 2001

고추냉이 물재배에서 토양의 배지조성이 고추냉이의 생육 및 수량에 미치는 영향을 구명하기 위해 시험한 결과 토양의 입경 조성은 일본에 비하여 마사토, 강모래에서는 2mm 이상의 자갈 함량이 적었고 조사의 분포가 많았다. 토양경도는 마사토와 강모래에서 상층은 $11.3{\sim}12.9$, 하층은 $12.5{\sim}15.1$ 사이에 분포하였으나, 난석에서 상층은 $5.5{\sim}5.8$, 하층은 $6.2{\sim}7.0$ 사이에 분포하여 난석의 경도가 가장 낮았다. 근계 분포는 경도가 낮은 난석에서는 좁고 깊게 분포하였으나, 경도가 높은 마사토, 강모래에서는 넓고 말게 분포하였다. 근경중은 난석에서 입수구 쪽은 766kg/10a, 퇴수구 쪽은 649kg/10a, 마사토에서 입수구 쪽은 338kg/10a, 퇴수구쪽은 334kg/10a, 강모래에서 입수구 쪽은 451kg/10a, 퇴수구 쪽은 332k9/10a로 난석 대비 입수구 쪽은 마사토 44%, 강모래 59%, 퇴수구 쪽은 마사토, 강모래 각각 51% 수준이었다.

• 한국토양비료학회지
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• 제49권5호
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• pp.434-439
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• 2016

Anthropogenic soil in cropland is formed in the process of subsoil reversal and the refill of soil into cropland. However, there was little information on the chemical properties within soil profiles in anthropogenic soil under rice paddy near the river. In this study, we investigated the chemical properties within soil profiles in the anthropogenic soil located at 4 sites in Gumi, Kimhae, Chungju, and Euiseong to compare with the natural paddy soil near the river. Among particle sizes, the sand content decreased under soil profiles but the silt and clay contents increased compared to the natural paddy soil in soil profiles. Organic matter content in topsoil of anthropogenic soil was lower than in that of natural soil, which was shown the contrary tendency within soil profiles. Also, the soil pH, available $P_2O_5$, and exchangeable cations were higher in anthropogenic soil compared to natural paddy soil at topsoil, which was maintained these tendency into soil depth. Nutrients may be equally distributed in anthropogenic soil during the process of refill in paddy soil near the river. This results indicated that anthropogenic soil would contribute to carbon sequestration, the mitigation of compaction, and reduction of fertilizer application in paddy soil. Therefore, characteristics of anthropogenic soil can be used for the soil management in cropland.

• 한국농공학회논문집
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• 제62권6호
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• pp.97-109
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• 2020

The objective of this study was to assess spatial variation of the target water quality criteria and excess rate in Nakdong river basin after the Total Maximum Daily Loads (TMDLs). For this, 41 total water quality monitoring stations were selected BOD and T-P data were collected from 2003 to 2019. The annual average water quality of BOD and T-P were calculated and compared with the target water quality for each stations by peroid. As a result of analyzing the BOD, Kumho A, Nakbon F, Namgang D, Miryang B, Wicheon B and Hoecheon A exceeded the target water quality criteria for two consecutive times. For T-P, Nakbon N, Naeseung B, Miryang A, Hwanggang A and Hoecheon A exceeded the target water quality criteria twice in a row. In the case of T-P, the target water quality excess rate was relatively low after the TMDLs implementation compared to before the TMDLs implementation. However, in the case of BOD, there was no difference in the target water quality excess rate before and after TMDLs. As a result, the overall annual average water quality shows a decreasing trend, but it is necessary to manage the water quality for the Nakdong river basin that exceed the target water quality.