• 한국농공학회지
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• 제35권3호
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• pp.74-80
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• 1993

Runoff simulation tests to investigate the flow mechanics of nonsuomerged overland flow in a natural grass intervening land system were condueted and a modified kinematic wave overland runoff model developed by Choi et al. (1993) was verified. Nonhomogeneity and heterogeneity of the soil, slope, local topography, infiltration, grass density, and the density and activity of the soil microhes and wild animals were the major factors affecting the flow. Streamlines were disturbed by grass stems and small concentrated flows due to the disturbed streamlines and local topography were observed a lot. Relatively larger concentrated flows were observed where bundles of grass were dominant than where individual grasses were growing. Predicted hydrographs were agreed verv well with measured hydrographs. Since the modified model considers grass density in computing flow depth and hydraulic radius, it can be better than existing kinematic wave model if it were used to route nonpoint source pollutant attenuation processes in many grass intervening land systems.

• 한국농공학회지
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• 제37권E호
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• pp.63-71
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• 1995

Three types of land use were investigated to describe the effect of land use on both surface and ground water quality. Typical land uses of a grazing pasture, Sudan grass field and paddy in Kangwon province were selected and flumes and monitoring wells were installed. Land managements were carefully monitored, water samples were collected periodically and analyzed with respect to nitrate, TP and TKN at a laboratory of Kangwon Provincial Institute of Health and Environment from August, 1993 to May, 1994. Runoff from the pasture was formed mostly with seeping subsurface flow in the lower areas of the pasture. A few overland flows were observed during heavy storms, and when it occurred, runoff increased sharply. For the Sudan grass field, runoff was formed with overland flow. Nitrate concentration in runoff from both land uses seemed not affected by runoff and ranged from 0.241 to 4.137mg'/1. TP and TKN concentrations from the pasture were affected by overland flow. When overland flow occurred, TP and TKN concentrations abruptly increased to 5.726 and 12.841mg/1, respectively, from less than 1.0mg/l. However, these concentrations from the Sudan grass field were quite stable ranging from 0.191 to 0.674mg/l for TP and 0A70 and 1.650mg/l for TKN. Nitrate concentration was significantly affected by land use(Sudan grass field) and the concentration increase reached about 2mg/l per lOOm ground water flow. Nitrate concentration from a well located in the middle of rice fields also was significantly higher than that measured from a well located relatively undisturbed mountain toe area. TP and TKN concentrations in shallow ground water affected by the depth of the monitoring wells. The deeper the monitoring wells, the less TP and TKN concentrations were measured.

• 한국수자원학회논문집
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• 제40권1호
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• pp.25-38
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• 2007

본 연구에서는 지표면 유출의 시간적 변화와 공간적 분포를 모의할 수 있는 격자기반의 도시유역 지표면 유출모형을 개발하였다. 개발된 모형에서는 지표면 유출의 메카니즘을 연속방정식과 Manning식을 결합한 비선형저류방정식으로 표현하고 있으며, 대상유역을 일정한 크기의 격자로 구성하고 개개의 격자마다 유출해석을 위한 지형정보와 수문정보를 입력하여 격자별 유출량을 계산 추적하게 된다. 본 모형을 이용하여 가상유역 및 실제 도시유역인 군자 배수구역에 대해서 시공간적인 유출양상을 모의해 봄으로써 모형의 적용성을 검토하였다. 이동강우에 대한 유출량의 변화, 유입구 설치에 따른 유출양상의 변화, 확률강우량에 대한 Huff 분위별 유출양상의 변화 등 도시지역의 유출특성을 분석하여 그 결과를 제시하였다.

• Water Engineering Research
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• 제1권4호
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• pp.321-330
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• 2000

The grid-based KIneMatic wave STOrm Runoff Model(Kim, 1998; Kim, et al., 1998) which predicts temporal variation and spatial distribution of overland flow, subsurface flow and stream flow was evaluated at two watersheds. This model adopts the single overland flowpath algorithm and simulates surface and/or subsurface water depth at each cell by using water balance of hydrologic components. The model programmed by C-language uses ASCII-formatted map data supported by the irregular gridded map of the GRASS(Geographic Resources Analysis Support System) GIS and generates the spatial distribution maps of discharge, flow depth and soil moisture of the watershed.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.752-757
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• 2009

In the last decade, many methods such as greet chamber, reservoir, or debris barrier, have been utilized to manage and prevent muddy water problem. The Vegetative Filter Strip (VFS) has been thought to be one of the most effective methods to trap sediment effectively. The VFS are usually installed at the edge of agricultural areas adjacent to stream or drainage ditches, and it has been shown that the VFS effectively removes pollutants transported with upland runoff. But, if the VFS is installed without any scientific analysis of rainfall-runoff characteristics, soil erosion, and sediment analysis, it may not reduce the sediment as much as expected. Although Soil and Water Assessment Tool (SWAT) model has been used worldwide for many hydrologic and Non-Point Source Pollution (NPSP) analysis at a watershed scale. but it has many limitations in simulating the VFS. Because it considers only 'filter strip width' when the model estimates sediment trapping efficiency, and does not consider the routing of sediment with overland flow option which is expected to maximize the sediment trapping efficiency from upper agricultural subbasin to lower spatially-explicit filter strip. Therefore, the SWAT overland flow option between landuse-subbasins with sediment routing capability was enhanced with modifications in SWAT watershed configuration and SWAT engine. The enhanced SWAT can simulate the sediment trapping efficiency of the VFS in the similar way as the desktop VFSMOD-w system does. Also it now can simulate the effects of overland flow from upper subbasin to reflect the increased runoff volume at the receiving subbasin, which is what is occurring at the field if no diversion channel is installed. In this study, the enhanced SWAT model was applied to small watershed located at Jaun-ri in South Korea to simulate diversion channel and spatially-explicit VFS. It was found that approximately sediment can be reduced by 31%, 65%, 68%, with diversion channel, the VFS, and the VFS with diversion channel, respectively.

• 한국수자원학회논문집
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• 제37권4호
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• pp.329-339
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• 2004

본 연구의 목적은 유역에서의 강우-유출 과정 모의를 위해 GIS에 기반을 둔 2차원 강우-유출 해석모형의 개발이다. 본 연구가 추구하는 세부 목표는 첫째, 강우--유출해석을 위한 2차원 모형을 개발하고, 둘째, 개발된 모형과 GIS를 연계하는 것이다. 모형에 포함된 수식화 과정은 다음의 네 가지로 요약학 수 있다. 시$\cdot$공간적으로 분포하는 강우의 처리과정과 침투과성, 유역의 유출을 추적하기 위한 1, 4, 8방향 흐름 추적과정, 그리고 하도 추적을 위한 1차원 해석과정이다. 개발된 모형에 Monte Carlo 모의기법을 결합하여 추계학적 모형을 구성하였다. 모형에 필요한 입력자료(고도, 토양도, 강우자료 등)의 구축과 모의결과의 도시를 위해 Arc/Info와 ArcView를 연계ㆍ활용한 시스템을 구성하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1997년도 학술발표회 논문집
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• pp.192-198
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• 1997

포화도의 공간적 변화인 지형지수를 계산하기 위한 다중흐름 알고리듬이 지형정보시스템인 GRASS와 연계되어 개발되었다. 본 연구는 소규모 농경지 배수구역에 대하여 적용하였다. 지하수위에 대한 타일 시스템의 영향이 DEM모형과 Laplace식에 의해서 효과적으로 고려될 수 있었다. 본 연구결과, 타일시스템을 고려한 유역은 타일시스템을 고려하지 않는 경우와 비교하여 높은 포화도를 가지고 있는 것으로 나타났으며, 예측된 riparian 유역은 실제의 유역조건과 잘 일치되고 있다. 본 연구에서는 지형지수를 산정함에 있어 타일 시스템의 효과를 고려해야 함을 제안하였다.

• 한국수자원학회논문집
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• 제33권S1호
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• pp.20-27
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• 2000

The grid-based KIneMatic wave STOrm Runoff Model(Kim, 1998; Kim, et al., 1998) which predicts temporal variation and spatial distribution of saturated overland flow, subsurface flow and stream flow was evaluated at two watersheds. this model adopts the single overland flowpath algorithm and simulates surface and/or subsurface water depth at each cell by using water balance of hydrologic components. the model programmed by C-language uses ASCII-formatted map data supported by the irregular gridded map of the GRASS (Geographic Resources Analysis Support System) GIS and generates the spatial distribution maps of discharge, flow depth and soil moisture of the watershed.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2000년도 학술발표회 논문집
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• pp.20-27
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• 2000

The grid-based KlneMatic wave STOrm Runoff Modei (Kim, 1998; Kim, et al., 1998) which predicts temporal variation and spatial distribution of saturated overland flow, subsurface flow and stream flow was evaluated at two watersheds. This model adopts the single overland flowpath algorithm and simulates surface and/or subsurface water depth at each cell by using water balance of hydrologic components. The model programed by C-language uses ASCII-formatted map data supported by the irregular gridded map of the GRASS (Geographic Resources Analysis Support System) GIS and generates the spatial distribution maps of discharge, flow depth and soil moisture of the watershed.

• 한국제4기학회지
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• 제17권2호
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• pp.79-84
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• 2003

This study revealed the differences in runoff processes of granite drainage basins in Korea and Mongolia by hydrological measurements in the field. The experimental drainage basins are chosen in Korea (K-basin) and Mongolia (M-basin). Occurrence of intermittent flow in K-basin possibly implies that very quick discharge dominates. The very high runoff coefficient implies that most of effective rainfall quickly discharge by throughflow or pipeflow. The Hortonian overlandflow is thought to almost not occur because of high infiltration capacity originated by coarse grain sized soils of K- basin. Very little baseflow and high runoff coefficient also suggest that rainfall almost does not infiltrate into bedrocks in K-basin. Flood runoff coefficient in M-basin shows less than 1 %. This means that most of rainfall infiltrates or evaporates in M-basin. Runoff characteristics of constant and gradually increasing discharge imply that most of rainfall infiltrates into joint planes of bedrock and flow out from spring very slowly. The hydrograph peaks are sharp and their recession limbs steep. Very short time flood with less than 1-hour lag time in M-basin means that overland flow occurs only associating with rainfall intensity of more than 10 mm/hr. When peak lag time shows less than 1 hour for the size of drainage area of 1 to 10 km2, Hortonian overland flow causes peak discharge (Jones, 1997). The results of electric conductivity suggest that residence time in soils or weathered mantles of M-basin is longer than that of K-basin. Qucik discharge caused by throughflow and pipeflow occurs dominantly in K-basin, whereas baseflow more dominantly occur than quick discharge in M-basin. Quick discharge caused by Hortonian overlandflow only associating with rainfall intensity of more than 10 mm/hr in M-basin.