• 한국환경과학회지
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• 제17권3호
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• pp.287-296
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• 2008

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3', 4,4', 5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs trom PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and $0.17ug/m\ell$ and $713.42{\mu}g/g$ and $3.73{\mu}g/g$, respectively, which contained $20\sim40$ times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.

• 농촌계획
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• 제11권4호
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• pp.67-74
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• 2005

The Doam watershed is located at alpine areas and the annual average precipitation, including snow accumulation, is significant higher than other areas. Thus, pollutant laden runoff and sediment discharge from the alpine agricultural fields are causing water quality degradation at the Doam watershed. To estimate soil erosion from the agricultural fields, the Universal Soil Loss Equation (USLE) has been widely used because of its simplicity to use. In the early spring at the Doam watershed, the stream flow increases because of snow melt, which results in erosion of loosened soil experiencing freezing and thaw during the winter. Also, extremely torrential rainfall, such as the typhoons 'RUSA' in 2002 and 'MAEMI' in 2003, caused significant amounts of soil erosion and sediment at the Doam watershed. However, the USLE model cannot simulate impacts on soil erosion of freezing and thaw of the soil. It cannot estimate sediment yield from a single torrential rainfall event. Also, it cannot simulate temporal changes in USLE input parameters. Thus, the Soil and Water Assessment Tool (SWAT) model was investigated for its applicability to estimate soil erosion at the Doam watershed, instead of the widely used USLE model. The SWAT hydrology and erosion/sediment components were validated after calibration of the hydrologic component. The R$^2$ and Nash-Sutcliffe coefficient values are higher enough, thus it is found the SWAT model can be efficiently used to simulate hydrology and sediment yield at the Doam watershed. The effects of snow melt on SWAT estimated stream flow and sediment were investigated using long-term precipitation and temperature data at the Doam watershed. It was found significant amount of flow and sediment in the spring are contributed by melting snow accumulated during the winter. Two typhoons in 2002 and 2003, MAEMI and RUSA, caused 33% and 22% of total sediment yields at the Doam watershed, respectively. Thus, it is recommended that the SWAT model, capable of simulating snow melt, sediment yield from a single storm event, and long-term weather data, needs to be used in estimating soil erosion at alpine agricultural areas to develop successful soil erosion management instead of the USLE.

• 대한지하수환경학회지
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• 제5권3호
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• pp.148-154
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• 1998

구봉광산은 과거 남한의 최대 금광중의 하나였다. 광산 주변 지역에서는 천부 지하수를 생활용과 농업용 수원으로 사용하여 왔다. 이 지역에서 Cd, Cu, Pb 및 Zn에 의한 토양오염이 보고되었으며, 이로부터 이 지역의 천부지하수의 수질과 광미로 인한 영향을 규명하고자 본 연구가 시작되었다. 인근의 하천수, 지하수 및 광미지역의 침출수 시료를 채취하여 Na, K Ca, Mg 등의 주양이온과 F, Cl, NO$_3$, SO$_4$, HCO$_3$, 등의 음이온 및 Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd, Pb, Se, As, Hg 등의 미량 오염원소등을 분석하였다. 분석결과로부터 4가지 유형의 수질특성을 구분하였으며, 이 지역의 지하수는 알칼리니티와 염도에 의한 농업용수로서의 위해성은 없는 것으로 판명되었다. 지하수 중의 주요염물질은 비소였으며, 유비철석(arsenopyrite)의 산화로부터 기인되는 것으로 사료된다. 따라서 기매립된 광미와 퇴적물을 파내는 것은 비소성분의 지하수로의 이동을 유발할 수 있다.

• 한국농림기상학회지
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• 제12권3호
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• pp.197-206
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• 2010

토지 이용이 다변화된 산지 유역에서 몬순 강우에 의한 환경 영향을 평가하는데 필수적인 기초 자료를 확보하기 위해 수질의 계절간 비교와 강우사상 집중샘플링의 방법을 활용하여 지표수 수질의 시공간적 변이 특성을 조사하였다. 유역 내 토지 이용을 반영하는 지표수 9개 지점을 대상으로 건 우기 수질의 계절적 차이를 비교하고, 2회의 강우사상에 대해 산림과 농경지 하천 2개 지점에서 집중 샘플링을 실시하였다. 대부분의 지점에서 건기보다 우기에 전기전도도와 $Cl^-$ 농도는 더 낮았으나, 총 금속 농도는 우기에 훨씬 더 높았다. 이는 우기에 늘어난 유량에 의해 용존 이온은 희석되고, 토양 침식량은 증가됐기 때문인 것으로 보인다. 한편 18mm의 적은 강우 시에 산림 하천의 수질에서는 거의 변화가 보이지 않은 데 반해, 농경지 하천에서는 부유토사와 용존 물질 농도가 모두 가파른 변화를 보였으며, 452mm의 많은 강우에 대해서는 농경지 하천은 물론 산림 하천에서도 큰 수질 변화를 관찰할 수 있었다. 농경지 하천의 Pb 농도는 부유토사 농도와 높은 양의 상관관계를 보였다. 제한된 샘플링 횟수와 조사지점으로 인해 결과 해석에 신중을 기해야 하겠지만, 전체 결과는 가파른 산지 유역에 농경지가 무분별하게 확장되면 강우의 변동폭과 극단화가 심해질 경우 토양 침식과 그에 따른 환경 영향의 취약도가 증가할 것임을 시사한다.

• 한국산림과학회지
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• 제101권4호
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• pp.574-578
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• 2012

산지소유역의 밤나무림, 소나무림, 개벌조림지를 중심으로 강우특성에 따른 임분별 탁도 변화 특성을 조사하고 탁도 발생에 영향을 미치는 산림환경 인자를 분석한 결과를 요약하면 다음과 같다. 임분별 탁도와 관련인자간의 분석에서 색도, 부유물질, 소류토사량, 경사, 강우강도, 선행무강우일수, 유역면적, 유로길이는 1%의 유의수준에서 양의 상관관계를 나타내었고, 누적강우량은 5% 유의수준에서 양의 상관관계를 나타내었다. 또한 산지계류수의 탁도발생에 영향을 미치는 인자를 분석한 결과 선행무강우일수, 강우강도, 유로길이, 색도 및 부유물질의 순으로 나타났으며, 탁도 발생에 영향을 많이 미치는 다중회귀식은 Y(탁도)=-28.125+0.047x(부유물질)+0.058x(색도)+1.518x(강우강도)+0.264x(유로길이)+1.837x(선행무강우일수)로 추정할 수 있었다. 따라서, 산림의 개발과 이용으로 인해 교란된 토양은 강우와 함께 계류로 유출되어 하류의 하천 및 호소의 수질에 영향을 미치므로 산림지역의 산지계류에서는 탁도에 영향을 주는 부유물질 및 토사유출 등을 줄일 수 있도록 버트리스 사방댐이나 수질정화용 사방댐 등 사방구조물의 설치가 필요할 것으로 보인다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권3호
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• pp.39-48
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• 2012

Visual MODFLOW, a three dimensional groundwater flow model, was used to analyze effects of a weir construction in an alluvial stream on the nearby groundwater flow system. A hypothetical conceptual model was developed to investigate how the groundwater level and the water budget could change after a weir construction depending on the location of tributary streams. A site example, dealing with the Juksan weir installed in the Yeongsan River, was also demonstrated to predict the effects of the weir construction. Model results show that impacts of a weir construction on the groundwater flow system greatly vary depending on how far a tributary is located and whether it is located downstream or upstream from the weir. Therefore, consideration of the location of tributaries in planning the location of a weir could effectively minimize the impacts of a weir construction on the groundwater flow system. It is also demonstrated that model results are highly dependent upon how the model is dealing with small tributaries and agricultural drainage channels, which can be easily found nearby the main streams, acting as major water bodies for groundwater discharge. The model for the Juksan area shows that the weir construction will change the direction of groundwater flow in some areas, leading to changes of groundwater quality and interaction of the Yeongsan River to the aquifer from a gaining to a losing stream. The model also predicted the areas where rise of groundwater level caused by the Juksan weir could adversely affect plant growth, and thereby suggested installing new drainage channels as a countermeasure to drawdown the groundwater level.

• 한국물환경학회지
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• 제27권6호
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• pp.855-861
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• 2011

Short-term effects of current velocity and turbid water on the benthic diatom community and water quality were examined in artificial channel ($20{\times}200{\times}10cm$) with two different experiments. The first and second experiments were consisted of different current velocities such as 1 L/min., and 1, 3, and 6 L/min., respectively. The concentration of turbid water is prepared with loess and fixed at 10 and 20 times of the turbidity of control inflow (10 NTU, LTW), respectively. At experiment 1 (EXP-1), introduction of turbid water increased dissolved oxygen, electric conductivity, pH and turbidity, but there were no differences between low- (100 NTU, MTW) and high-turbid water (200 NTU, HTW). However, experiment 2 (EXP-2) did not change any environmental parameters except dissolved total and inorganic nitrogen like EXP-1. MTW in EXP-1 strongly stimulated the growth of benthic diatom, while both MTW (150 NTU) and HTW (300 NTU) in EXP-2 did not increase or decrease the diatom abundance. Over the study, the dominant species was four, Aulacoseira ambigua, Cyclotella stelligera, Aulacoseira granulata and Achnanthes minutissima. In EXP-1, two highest species in abundance, A. ambigua and A. granulata were highly grown in MTW, while Achnanthes minutissima high in HTW adversely. These results indicate that the introduction of turbid water can play an important role in the shift of water quality and benthic diatom community in stream ecosystem, especially inflow of soil water in low current velocity.

• 한국물환경학회지
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• 제25권1호
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• pp.102-111
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• 2009

Turbid storm runoff from intensive highland agriculture area has emerged as the major problem of water quality deterioration in the upstream region of the Han River. High slope of the upland combined with high rate of fertilization and intensive plowing causes high rate of soil erosion, and subsequently high suspended sediment and phosphorus content in the runoff water. The variations of water quality during rain spells were surveyed for two years (2005 and 2006) in the Jawoon Stream that is one of hot spots of intensive horticulture discharging turbid storm runoff. SS and TP showed large increase according to the increase of flow rate, whereas TN and BOD showed less fluctuations. Mean EMCs of SS and TP measured for nine rain events were as high as $207mgSS{\cdot}L^{-1}$ and $0.27mgP{\cdot}L^{-1}$, respectively. The export coefficient of SS and TP per area of cultivated field were calculated as $11,912kgSS{\cdot}yr^{-1}{\cdot}km^{-2}$ and $785kgP{\cdot}yr^{-1}{\cdot}km^{-2}$, repectively, which are significantly higher than reports of other area. It can be concluded that SS and TP in the runoffs were high enough to impose major threat to aquatic habitats, and the highland agriculture should be the main target of water quality management or habitat conservation in the study area.

• Journal of Ecology and Environment
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• 제38권2호
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• pp.145-156
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• 2015

This study was based on water quality data of the Lake Doam watershed, monitored from 2010 to 2013 at eight different sites with multiple physiochemical parameters. The dataset was divided into two sub-datasets, namely, non-rainy and rainy. Principal component analysis (PCA) and factor analysis (FA) techniques were applied to evaluate seasonal correlations of water quality parameters and extract the most significant parameters influencing stream water quality. The first five principal components identified by PCA techniques explained greater than 80% of the total variance for both datasets. PCA and FA results indicated that total nitrogen, nitrate nitrogen, total phosphorus, and dissolved inorganic phosphorus were the most significant parameters under the non-rainy condition. This indicates that organic and inorganic pollutants loads in the streams can be related to discharges from point sources (domestic discharges) and non-point sources (agriculture, forest) of pollution. During the rainy period, turbidity, suspended solids, nitrate nitrogen, and dissolved inorganic phosphorus were identified as the most significant parameters. Physical parameters, suspended solids, and turbidity, are related to soil erosion and runoff from the basin. Organic and inorganic pollutants during the rainy period can be linked to decayed matters, manure, and inorganic fertilizers used in farming. Thus, the results of this study suggest that principal component analysis techniques are useful for analysis and interpretation of data and identification of pollution factors, which are valuable for understanding seasonal variations in water quality for effective management.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.102-106
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• 2008

본 연구는 SWAT(Soil and Water Assessment Tool) 모형에서 공간입력자료의 다양한 해상도에 의한 수문-수질 모의결과를 비교분석 하고자 하였다. 경안천유역 상류의 농촌 소유역($1.21\;km^2$)을 대상으로 Case A(2m DEM, QucikBird 토지이용도, 1/25,000 토양도), Case B(10m DEM, 1/25,000 토지이용도, 1/25,000 토양도), Case C(30m DEM, Landsat 토지이용도, 1/25,000 토양도)에 해당하는 해상도별 공간입력자료를 구축하였다. 모형의 적용성 평가를 위해 먼저, 경안수위관측소 상류유역($255.44km^2$)을 대상으로 $1999{\sim}2002$년까지 4개년의 자료를 이용하여 유출량 및 Sediment, T-N, T-P에 대한 모형의 검보정을 실시하였다. 유출량에 대한 Nash-Sutcliffe 모형효율은 평균 0.59의 결과를 얻었으며, Sediment, T-N, T-P는 각각 2.08 tons/yr, 4.30 tons/yr, 0.70 tons/yr의 RMSE 오차로 검보정되었다. 모형의 검보정 후, 농촌 소유역을 대상으로 다양한 공간자료(Case A, B, C)를 적용하여 수문, 수질모의를 실시한 결과, 유출량은 토지이용도 해상도에 의한 모의결과의 불확실성이 가장 큰 것으로 분석되었다. QuickBird 토지이용의 유역평균 CN값이 1/25,000과 Landsat 토지이용에 비해 0.4, 1.8 더 크게 분석됨으로서 총유출량도 증가하였다. 유사량과 영영물질 오염부하량에 대한 수질모의 결과는 USLE 인자의 평균 LS 및 K, CFRG 값의 순서로 해상도별 모의결과의 불확실성이 가장 컸으며 토지이용도에 의한 평균 C값에는 큰 변화가 없는 것으로 분석되었다. Case A의 유사량은 B와 C에 비해 23.7%, 50.6% 증가하는 것으로 나타났으며, 유사량 증가에 따른 T-N, T-P 부하량 역시 Case A, B, C 순으로 높게 평가되었다.