• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.27-33
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• 2011

Infiltration plays an important role in the urban water cycle. Infiltration has a potential to contribute to groundwater recharge in addition to runoff reduction. However, infiltration in urban areas has been considered only as a means of runoff reduction. Conventional design methods for infiltration facilities assume soils to be fully-saturated for the sake of simplicity. The amount of groundwater recharge can not be estimated properly with this scheme. Hence, the characteristics of the unsaturated soil condition need to be considered. The finite element model using SEEP/W to estimate infiltration under the unsaturated condition is presented. Infiltration tests for Joomonjin sand are performed and the infiltration behavior of Joomoonjin sand under the unsaturated condition is measured experimentally to verify the validity of the finite element model. The results from comparing infiltrated volume between the saturated and the unsaturated conditions under the same soil and rainfall conditions show that the infiltrated volume in the unsaturated condition is two times bigger than that in the saturated condition.

• 한국농공학회논문집
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• 제52권6호
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• pp.135-144
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• 2010

This study was performed to suggest a soil loss reduction skill through estimating soil erosion from a small watershed including each type of sloping agriland by using GEOWEPP model. Experimental watershed at Gangwon province was selected for very typical sloping fields of highland agriculture in Alpine area. Runoff discharge and sediment load, hourly rainfall amount occurred during storm event were gauged, and weather data were obtained from Daegwallyeong meteorological station. The results of GEOWEPP model estimation showed that relative error values for total runoff discharge and sediment load were 3 %, -14.5 % respectively. Based on the result, soil erosion and waterway path map for each hillslope were made to select target hillslope. Several hillslopes of severe soil erosion were analyezed and then the optimal vegetative filter strip construction width and waterway path to plant grass were decided by using GEOWEPP Model.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.27-35
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• 2012

Recently, there has been increasing interest in the use of rain garden systems as environmentally friendly ecological infrastructures for controlling stormwater runoff and managing non-point source pollution and information for the contamination of soil and plants can be essential for sustainable rain garden management. In this study, four rain garden mesocosms, namely single species planting with Rhododendron lateritium, single species planting with Zoysia japonica, mixed planting with R. lateritium and Z. japonica, and control without plants, were tested to investigate the change in concentrations of nutrients (N and P) and heavy metals (Cd, Cu, Pb, and Ni) in the soil and plants used in the rain garden system. The presence of plants resulted in greater nutrient retention in soil and lower potential leaching from the system. All systems showed an increase in the heavy metal concentrations in soil. The concentrations of most heavy metals were found to be higher in the herbaceous plants (Z. japonica) than in the shrubs (R. lateritium). The belowground part (root) had higher heavy metal concentrations than the aboveground part (leaf) but also showed a potential increase in leaves, and hence, careful plant management should be considered during rain garden operation.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.138-138
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• 2021

Flash floods are one of the types of natural hazards which has severe consequences. Flash floods cause high mortality, about 5,000 deaths a year worldwide. Flash floods usually occur in mountainous areas in conditions where the soil is highly saturated and also when heavy rainfall happens in a short period of time. The magnitude of a flash flood depends on several natural and human factors, including: rainfall duration and intensity, antecedent soil moisture conditions, land cover, soil type, watershed characteristics, land use. Among these rainfall intensity and antecedent soil moisture, play the most important roles, respectively. Flash Flood Guidance is the amount of rainfall of a given duration over a small stream basin needed to create minor flooding (bank-full) conditions at the outlet of the stream basin. In this study, the Sejong University Rainfall-Runoff model (SURR model) was used to calculate soil moisture along with FFG in order to identify flash flood events for the Geum basin. The division of Geum river basin led to 177 head-water catchments, with an average of 38 km². the soil moisture of head-water catchments is considered the same as sub-basin. The study has measured the threshold of flash flood generation by GIUH method. Finally, the flash flood events were used for verification of FFG. The results of the validation of seven past independent events of flash flood events are very satisfying.

• 한국환경복원기술학회지
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• 제18권6호
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• pp.191-200
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• 2015

This study was carried out to investigate coefficient and exponent of runoff energy in MUSLE for small forest watershed, Hwachoen watershed in Gangwon-do. For 15 rainfall events, runoff volume, peak discharge and sediment yield were measured and these data were used to calculate coefficient and exponent of runoff energy. The results of this study showed that $LS{\bullet}K{\bullet}C{\bullet}P$ factors of MUSLE were affected by slope steepness. The coefficient and exponent of runoff energy were validated with coefficient of efficiency of 0.92 and these values were suggested to 0.002 and 0.81 respectively. The comparison of the coefficients and exponents between Hwacheon and other forest watersheds showed that these values would reflect the effect of forest management within watershed.

• 환경영향평가
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• 제16권2호
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• pp.169-176
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• 2007

The paved areas in nonpoint source are highly polluted landuses because of high imperviousness and pollutant mass emissions, such as sand, cereals, and dust from vehicle activities. Most of them in highways are collected by cleaning trucks or discharged to the adjacent soil and water system through the drain ditch in stormwater. Therefore, it is necessary to investigate the relationship between water concentration and total pollutant loadings from the paved areas. From the experiment, CODcr concentration of the cleaning wastewater was 17 times greater than that of the stormwater runoff. Also, concentrations of heavy metals (Cu, Fe, Zn) were 1.3 to 1.5 times higher when compared to the stormwater runoff. While total discharged loadings was insignificant in the cleaning wastewater. In conclusion, these results provide some evidence that the stormwater runoff may be managed carefully to the aspect of total pollutant loadings and the cleaning wastewater may be handled cautiously with the pollutant concentrations in highways.

• 한국농공학회지
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• 제42권2호
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• pp.63-70
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• 2000

The present study was carried out for 7-months (from October 1.1997 to April 30. 1998) at a rice cultivation area blocked from livestock farming, farmstead and industrial complex to investigate the runoff loading of nitrogen and phosphorus in a plot(5,000$m^2$) paddy field areas. The runoff loading of total-N, amminia-N nitrate-N and total-P were 12.96kg/ha, 5.42kg/ha, 1.52kg/ha and 1.41kg/ha , respectively. When the runoff loading of nutrients was compared by dissolved and adsorbed forms, about 66% of total-N by dissolved form and the rest 34% by adsorbed form were flowed into streams. But 56% of total-P by adsorbed form and the rest 44% by dissolved form were flowed into streams. The phosphrous compounds , which were flowed into streams by runoff sediments and then sedimented, keep exchanging with water at water body in undelivered condition. And it moves gradually into water layer. This process can cause eutrophication continually and repeatedly in water environment . So, a sound program is needed to reduce soil erosion from farmlands.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.14-19
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• 2021

Aim of this research was to investigate the effects of Digital Elevation Model (DEM) for sensitivity analysis with two types of DEMs: 1 to 24,000 and 1 to 250,000 DEM. Another emphasis was given to the development of methodology for processing DEMs to create ArcGIS Pro and GRASS layers. This was done while developing water quality system modeling using DEMs which were used to model hydrological processes and SWAT model. Sensitivity analysis with DEMs resulted in different runoff volumes in the model simulation. Runoff volume was higher for the 1:24,000 DEM than 1:250,000 DEM, probably due to the finer resolution and slope which increased the estimated runoff from the watershed. Certainly the DEMs were factors in precision of the simulations and it was obvious during sensitivity analysis that DEMs had significant effect on runoff volumes. We suggest, however, that additional comparative research could be conducted involving more parameters such as soil and hydrologic parameters to provide insight into the overall physical system which the SWAT model represents.

• 한국수자원학회논문집
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• 제47권12호
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• pp.1121-1134
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• 2014

유사발생 잠재성 및 토양침식으로 인한 유사발생 위험성이 높은 것으로 평가된 내성천유역을 대상으로 강우-유출-토양침식-유사이송으로 이어지는 유역단위의 분포형 모형을 구축하였으며 유출과 유사농도 모의 결과에 주요한 영향을 미치는 조도계수 및 투수계수의 민감도 분석을 실시하였다. 모의결과, 내성천유역의 토지 피복이 숲인 지역의 조도계수를 0.4에서 0.45로 변경하여 지표수 유출 유속을 감소시킴으로써 향석 지점에서의 유출곡선에 미치는 영향을 분석하였으나 유출수문곡선의 변화에 영향을 미치지 않는 것으로 나타났으며 평균 유사농도 값과 유사농도의 범위에 있어서도 모의 결과가 근소하게 증가하나 유의한 변화는 없는 것으로 나타났다. 투수계수에 대한 민감도 분석 결과, 투수계수 값을 저감 시킬수록 총 유출량 및 첨두 유출량은 점차 증가하는 것으로 나타났다. 유사농도 모의의 경우에도 투수계수를 저감시킬수록 모든 지점에서 평균 유사농도 및 유량에 따른 유사농도 범위가 증가하였으며, 향석 지점의 경우 투수계수를 50% 저감하였을 때 유사 농도 모의 값이 유량-유사량 관계식에 의해 계산된 값과 가장 근사한 것으로 나타났다.

• Applied Biological Chemistry
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• 제40권4호
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• pp.334-341
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• 1997

강우에 의한 농약의 토양표면 유출특성을 알아보고자 인공강우(20 mm/hr)에 의한 실내 유출실험을 7개 농약을 대상으로 수행한 결과, 유출율은 metolachor 57.0%, alachlor 14.2%, chlorothalonil 13.2%, chlorpyrifos 7.9%, EPN 7.2%, phorate 7.1%, captafol 2.8%였고, 평균 유출농도는 각각 940, 399, 55, 7.0, 9.3, 151, 7.0 ppb였다. 유출율과 농약의 물리화학적 특성(수용성, 분배계수, 토양흡착계수)과의 상관관계를 보면 실내유출실험에서 수용성과의 상관성이 높았으며(r=0.923), 그 이외의 실험조건에서도 수용성 보다 높지는 않았지만 상관성이 유사하였다. 이 결과를 바탕으로 실내 실험결과를 이용한 포장에서의 유출을 예측가능성을 확인하고자 유출을 예측식 $[Y=0.2812{\times}10{\exp}(0.261logWS-0.366)+0.3594{\times}10{\exp}(-0.545logKoc+1.747)+0.3594{\times}10{\exp}(-0.362log\;Kow+1.105]$과 전환식을 도출하였다. 자연포장에서 수행한 captafol의 유출율과 유출율 예측식을 이용하여 계산한 결과를 비교해 보면 예측식에 의한 유출율은 실험치보다 약 6배 이상 높았으나 전환식을 사용시 유출율은 실험치와 유사하였다. 따라서 실내유출 실험을 통한 유출율과 대상농약의 수용성, 분배계수, 토양흡착계수를 사용하여 유도한 유출예측식과 전환식을 이용하여 포장에서 강우에 의한 이들 농약의 유출율 예측이 가능하였다.