• 한국물환경학회지
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• 제25권5호
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• pp.742-749
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• 2009

To examine the characteristics of the nutrient release from the sediments in two reservoirs, Lake Paldang and Lake Cheungpyeung, we analyzed physical and chemical properties of the sediments and calculated the nutrient release rates from the sediments. The particle properties of sediments in Lake Paldang changed from silt to sand after summer rainy season, especially in the water area of the Kyeungan River where the water depth was shallow and the width of river was narrow. The sediments in Lake Cheungpyeung had higher contents of silt and clay than in Lake Paldang, and the particle size was not much different before and after rainfall. The release rates of nutrients in two lakes varied with the kind of nutrients and the season. The release rates of DTN and ${NH_4}^+-N$ in Lake Paldang were faster in spring than autumn. But the Lake Cheungpyeung showed similar values of release rates before and after summer rainy season. ${NO_3}^--N$ and phosphorous were not released from sediments or were absorbed into sediments all the time in two lakes. Compared with other lakes, the sediments of two lakes consisted of bigger particles and had a lower organic matters content than other lake-type reservoirs. Due to the short hydraulic retention time and no stratification throughout the year in Lake Paldang and Lake Cheungpyeung, the release rates of nutrients from sediment in these reservoirs were lower than other lakes and this seems to be a typical characteristic of river-type reservoirs.

• 상하수도학회지
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• 제31권6호
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• pp.567-575
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• 2017

It is not cost effective to raise the density of catch basins in preparation for heavy rainfall in terms of construction and maintenance. Our researchers have developed the new catch basin for increasing interception capacity of runoff with internal filtration structure. To compare interception capacity of an existing catch basin with the invented catch basin, a hydraulic experiment device with 4% of road gradients and 0.2% of road gradients was constructed. For runoff conditions of 4.4 l/s, 6.7 l/s and 10.4 l/s, capability of runoff and separation capability of debris (sand and leaves) were evaluated. As the main experimental results, the effectiveness of the developed catch basin has been verified with an increase in interception rate of approximately 22% for the runoff of 6.7 l/s as heavy rainfall. However, the results of invented catch basin showed only 4.5% of settlement rate of debris regarding sand. Therefore, the authors proposed an improved tilted screen structure additionally. After reviewing the performance of improved catch basin, application of the invented catch basin is expected to drain runoff effectively when it is applied to the faulty road drainage section.

• 식물병연구
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• 제7권3호
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• pp.150-154
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• 2001

세균성벼알마름병의 발생 예측 모델을 만들기 위하여 출수기의 기상 환경과 병 발생과의 관계를 자료분석(1992~2000)과 온실 및 포장시험을 통해 조사하였다. 세균성벼알마름병의 발생이 많은 해는 '94, '95, '98, 2000년이었고, 중만생종 출수기인 8월 상.중순에 고온이 지속되면서 연속강우가 많았다. 반면 병 발생이 적었던 '93년은 강우량과 강우일수는 많았으나 저온이었고, '97년에는 온도는 높았으나 강우가 적은 경향이었다. 출수기에 접종 후 습실처리 하였을 때(24시간 이상) $10^2$cfu/ml에서부터 발병하기 시작하여 접종농도가 높을수록 발병도가 높아져 $10^{8}$ cfu/ml에서는 86.1%의 발병도를 보였다. 습실처리를 하지 않은 경우에는 $10^{8}$ cfu/ml에서만 12.5% 발병하였다. 또한 발병도가 증가함에 따라 천립중과 등숙률이 현저히 감소하였다.

• Journal of Radiation Protection and Research
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• 제27권3호
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• pp.165-170
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• 2002

핵종의 지표 침적 모델의 고찰과 함께 방사성물질의 공기중 농도로부터 건침적 뿐 아니라 습침적에 따른 농작물 오염 영향을 분석, 고찰하였다. 이를 위해 방사성물질의 지표 침적량으로부터 농작물의 오염을 평가하는 기존 동적 섭식경로모델을 공기중 농도 또는 지표 침적량으로부터 평가할 수 있도록 개선하였다. 평가결과, 방사성물질의 지표 침적량은 습침적에 의한 영향이 건침적에 의한 영향보다 뚜렷이 높으나, 농작물의 오염정도는 핵종, 강우율 등에 따라 다르게 나타났다. 이러한 현상은 방사성물질의 지표 침적과 농작물에로의 차단중 어느 과정이 농작물 오염에 보다 지배적으로 작용하는가에 기인한다.

• 한국수자원학회논문집
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• 제38권7호
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• pp.517-526
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• 2005

현재 우리나라에서 주로 사용되는 지하수 함양량 추정방법은 지하수 감수곡선에 의한 기저유출분리법과 관측공의 자료를 이용한 지하수위 변동법으로 대별된다. 기저유출분리법은 연단위기반의 집중형 개념의 접근법을 사용하며, 지하수위변동곡선해석법은 유역단위의 물수지 개념보다는 국지적인 지하수 관측정의 변화에 주로 의존하고 있다. 한편 지하수 함양량은 기후조건, 토지이용, 관개와 수리지질학적 비균질성에 의해 현저한 시공간적 변동성을 나타내고 있어서 위의 두 가지 방법으로는 이같은 특성을 고려하는데 여러 가지 한계를 보인다. 이에 본 연구에서는 준분포형 강우-유출모형인 SWAT모형을 이용하여 공간적변동성을 고려한 일단위 함양량 산정기법을 제시하였다. 이 방법을 이용하면 기존의 유역 대표 함양량 대신 각 소유역의 비균질한 특성을 반영한 함양량의 분포를 산정할 수 있다. 산정된 일단위 함양량은 기후조건 토지이용 및 수리지질학적 비균질성과 토양층에서의 지체등 물리적인 거동까지 반영된 것이어서 기존의 간접적 추정방식에 의한 연단위 함양률을 크게 개선할 수 있을 것으로 기대된다.

• 한국습지학회지
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• 제21권1호
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• pp.9-15
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• 2019

대기천 유역은 한강 상류에 위치하고 있으며, 대표적인 고랭지 채소재배단지 중의 하나로 강우기 대규모 탁수를 배출하여 한강 상류의 수질 및 수생태계에 심각한 영향을 미치고 있다. 효과적인 탁수관리 및 정책제안을 위해서는 강우기 하천유량과 탁수(SS)농도의 특성 및 원인분석이 우선시되어야 한다. 본 연구에서는 대기천 유역을 대상으로 강우기 유량과 SS농도 사이의 관계를 분석하고 이를 통해 탁수발생 특성을 분석하였다. 연구 결과 보통의 홍수유량상태에서는 다양한 주변 환경요소로 인해 임의적으로 변화하는 것으로 나타났다. 반면, 첨두홍수량상태에서는 SS농도가 매우 높게 나타났으며, 이는 현장방문관측을 통해 농경지 발생원뿐만 아니라 첨두홍수량에 따른 가파른 계곡과 사면의 붕괴에 의한 영향이 크게 기여한 것으로 판단된다. 따라서 통상적인 발생원관리대책과 함께 경지주변 사면안정과 하상유실을 제어할 수 있는 구조적 최적관리방법이 필요할 것으로 판단된다.

• 한국물환경학회지
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• 제26권5호
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• pp.775-780
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• 2010

Over 90% of the livestock excretions were treated and utilized by land application in Korea. Excessive application of the livestock manure as fertilizer has been issued as a main pollutant source in groundwater and watersheds. This study was seasonally conducted to identify the discharging characteristics with a certain artificial rainfall intensity (13 mm/hr) in terms of surface runoff, groundwater, and soil residue mass depending on the livestock manure types. A experimental field was constructed with three different sites that pig liquid fertilizer (LF), cattle manure (CM), and standard (S). The pig liquid fertilizer of 1,200 L and cattle manure of 900 kg were sprayed on each site ($50m^2$). The standard area was firmly prevented from any other contaminants. In the LF site, farmland discharging rate (FDR) was computed as 0.006 in CODcr, 0.015 in TN, and 0.029 in TP, resulted from the mass balance among total injection mass, surface runoff and groundwater. In the CM site, 29% of the nitrogen and phosphorus in each were discharged to the surface, and 64% and 58% of them were remained in the farmland. Surface runoff rate of the CM was higher than that of the LF, resulted from the solid form of the CM.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.459-462
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• 2004

This study assesses groundwater vulnerability to contaminants in 12 administrative districts of the city of Changwon, using DRASTIC technique. DRASTIC was originally applied to situations in which the contamination sources are at the ground surface, and the contaminants flow into the groundwater with infiltration of rainfall. However, groundwater contamination in urban areas can also be related to excessive pumping resulting in a lowering of the water level. The correlation coefficient between minimum DRASTIC indices and the degree of poor water quality for 10 districts is low as 0.40. The correlation coefficients between minimum DRASTIC indices and the groundwater discharge rate, and between minimum DRASTIC indices and well density per unit area are 0.70 and 0.87, respectively. Thus, to evaluate the potential of groundwater contamination in urban areas, it is necessary to consider other factors such as groundwater withdrawal rate and well density per unit area with ratings and weights as well as the existing six DRASTIC factors.

• 상하수도학회지
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• 제10권1호
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• pp.69-77
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• 1996

To evaluate the change of the groundwater flow and the water table response resulting from urbanization, two cases of the transient three-dimensional numerical simulations were performed. Variations of the groundwater flow system caused by withdrawals were analyzed. Two cases of infiltration rates were applied in this study to verify the water table changes. One is the rate under the circumstance during 1994 and the other is the revised rate. The numerical results from this study indicated that groundwater flow was influenced by human impacts. Groundwater flow has been concentrated to Taegu Textile Complex area where had large amount of pumping. Water table so far decreased -2.76m a year due to withdrawals. Water tables of many points were increased more than 30cm when the surface was reformed by infiltrating the rainfall. It was appeared that the improvement of surface to recharge the precipitation was very important to preserve and manage for the groundwater.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.509-512
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• 2001

In this study, pollutant load from paddy field was estimated by regression equation from 5 to 8 in 2001. During study period, total rainfall was 511.3mm and runoff discharge was 968.71mm. Regression equation between flow rate(m3/s) and pollutant loading rate(g/s) is exponential relationship. For site 1, coefficient of determination (R2) for $COD_{cr}$, T-P, T-N were 0.7068, 0.8441, 0.6806 respectively and site 2, 0.9369, 0.8855, 0.4262 respectively. Considering unit loads, Jun was the highest valus as 13.85 $COD_{c}kg/km2/day$, 0.24 T-Pkg/km2/day, 1.22 T-Nkg/km2/day. Until study period, total $COD_{cr}$ load estimated regression equation is 19.32kg/km2/day and, T-P, T-N were 0.264, 1.88 respectively