• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.558-564
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• 1998

Flow rate, watertable and selected water quality of 2 small rural streams and 6 observation well located in Kangwon-do, Korea, were monitored land use of the watersheds was investigated to describe the trend of stream water quality for 2 years and groundwater quality for 1 year. Water qualities were analyzed with respect to BOD, SS, T-N, Nitrate, T-P and E-coli. Stream water quality and gorundwater quality directly concerned with the amount of rainfall and paddy fields. but water quality of watersheds is existed with other factor. Therefore, We have to continued monitoring and developing the best management practice.

• 물과 미래
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• 제26권3호
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• pp.47-61
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• 1993

수정 tank 모형의 입력, 구동, 출력 및 매개변수의 보정을 실시할 수 있는 쉘 프로그램 DSFS를 개발하고, 중소 유역의 일 유출량의 추정에 적용하도록 하였다. 수정 tank 모형은 유역의 일별 증발산 손실을 추정함으로써 유출량을 정의하도록 하였으며, 증발손실량은 배재 증발산량에 토양수분계수 및 토지 이용상태에 따른 월별 작물피복계수를 써서 조정하도록 하였다. 모형의 매개변수를 보정하고, 매개변수와 유역 특성인자와의 관계를 얻었다. 개발된 쉘 프로그램을 미계측유역에 적용하였으며, 일유출량 추정에서 최적화 결과와 유사한 값은 보였으나, 년 유출량은 10% 정도 큰 값은 보였다.

• 한국물환경학회지
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• 제21권6호
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• pp.617-623
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• 2005

Forestry and agricultural land uses constitute 85% of Korea and these land uses are typically mixed in many watersheds. Biological Oxygen Demand (BOD) concentration is a primary factor for managing water qualities of the water resources in Korea. BOD loadings from diffuse sources, however, not well monitored yet. This study aims to assess BOD loadings from diffuse sources and their affecting factors to conserve quality of water resources. Event Mean Concentration (EMC) of BOD was calculated based on the monitoring data of forty rainfall events at four agricultural-forestry watersheds. Exceedence cumulative probability of BOD EMCs were plotted to show agricultural activities in a watershed impacts on the magnitude of EMCs. Prediction equation for each rainfall event was proposed to estimate BOD EMCs: $EMC_{BOD}(mg/L)=EXP(0.413+0.0000001157{\times}$(discharged runoff volume in $m^3$)+0.018${\times}$(ratio of agricultural land use to total watershed area).

• 한국관개배수논문집
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• 제13권2호
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• pp.274-282
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• 2006

The objective of this study was to develop a hydrologic simulation model to predict daily streamflow from a small agricultural watershed considering irrigation return flow. The proposed IREFLOW(Irrigation REturn FLOW) model consists of hillslope runoff model, irrigation scheme drainage model, and irrigation return flow model, and simulates daily streamflow from an irrigated watershed. Two small watersheds were selected for monitoring of hydrological components and evaluating the model application. The relative error (RE) between observed and simulated daily streamflow were 2.9% and 6.4%, respectively, on two small agricultural watersheds (Baran and Gicheon) for the calibration period. The values of RE in daliy streamflow for the validation period were 6.0% for the Baran watershed, and 2.8% for the Gicheon watershed.

• Korean Journal of Hydrosciences
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• 제2권
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• pp.1-12
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• 1991

To estimate the peak discharge from the small rural watersheds, 53 storm events of seven small watersheds from 1972 to 1989 were selected and were analyzed by the multiple regression technique. The peak values by the new prediction method developed in this study were also compared to the real data of Banwol Basins and the estimated peaks of the several watersheds which were analyzed by the Korean engineering companies. These values were also compared to the results from the other method, i.e. the Rational Method, the Kajiyama Method, the Nakayasu Unit Hydrograph companies. Through Method, the Area Routing Method, etc., which are favored by the Korean engineering companies. Through these comparisons, it is proved that the proposed method may be used for day-to-day use without any problem. However, there should be some modifications and improvements as more data are available in the future.

• 물과 미래
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• 제23권3호
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• pp.351-361
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• 1990

식생계로 피복되고 투수성 토양을 갖는 산지유역에서의 점유출량 결정을 위해 초과우량 추정모형을 유도하였다. 산림에 의한 canopy차단 및 풀, 낙엽, 농작물 등에 의한 지표피복차단저축을 고려하고, 유역 포화시의 증발산량을 계산하여 관측강우로부터 지표 흙에 도달되는 순강우량을 결정하였다. 부정강우사상에 적용할 수 있도록 수정된 Green-Ampt모형으로부터 침투율을 결정하여 초과우량을 산정하였고, IHP 대표시험유역 가운데 장평유역의 실제호우사상에 적용하여 손실율, 유출율 및 유출발생시간 등을 결정, 적용성 여부를 검토하였다.

• 한국물환경학회지
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• 제22권3호
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• pp.504-512
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• 2006

In order to estimate microbial contaminant discharge from diffuse sources, rainfall runoff was monitored at forestry, agriculture and urban watersheds. Total coliform and E. coli were monitored at the study watersheds as they are regulated by the environmental laws. Concentration and EMC (Event Mean Concentration) of coliform of rainfall runoff at the urban watershed were the highest followed by those from agricultural and forestry watersheds. By monitoring coliform concentrations of overlying water and sediment at five monitoring points in the downstream of the Geum River, average concentration from spring to summer was higher than those values from fall to spring. Coliform concentrations in the pore water were higher compared to those of overlying water and closely related with flow rate of the river.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.428-428
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• 2017

In this study, three optimization techniques efficiency is assessed for calibration of the GR4J model for streamflow simulation in Selmacheon, Boryeong Dam and Kyeongancheon watersheds located in South Korea. The Penman-Monteith equation is applied to estimate the potential evapotranspiration, model calibration, and validation is carried out using the readily available daily hydro-meteorological data. The Shuffled Complex Evolution-University of Arizona(SCE-UA), Uniform Adaptive Monte Carlo (UAMC), and Coupled Latin Hypercube and Rosenbrock (CLHR) optimization techniques has been used to evaluate the robustness, performance and optimized parameters of the three catchments. The result of the three algorithms performances and optimized parameters are within the recommended ranges in the tested watersheds. The SCE-UA and CLHR outputs are found to be similar both in efficiency and model parameters. However, the UAMC algorithms performances differently in the three tested watersheds.

• 한국환경과학회지
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• 제28권4호
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• pp.423-433
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• 2019

This study was carried out to identify the problems of the underground watersheds on Jeju Island, and to establish the hydraulic groundwater basin to be used as basis for the analysis of the groundwater model. In order to evaluate the adequacy of the groundwater basin on Jeju Island, a correlation analysis between elevation and groundwater level was conducted using data from 125 observation wells. The analysis, conducted with an elevation step of 100 m, exhibited values of R2 in the range 0.1653-0.8011. No clear correlation was observed between elevation and groundwater level. In particular, the eastern and western areas showed an inverse proportionality between elevation and groundwater level. The Kriging technique was used to analyze the underground water level data and to define the equipotential lines for all areas of Jeju Island. Eight groundwater watersheds were delineated by considering the direction of groundwater flow, the positions of the observation wells, and the long and short axes of the watersheds.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.738-739
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• 2015

The main objective of this study, "Spatial Downscaling of Precipitation from GCMs for Assessing Climate Change over Han River and Imjin River Watersheds", is to carry out over Han River and Imjin River watersheds. To this end, a statistical regression method with MOS (Model Output Statistics) corrections at every downscaling step was developed and applied for downscaling the spatially-coarse Global Climate Model Projections (GCMPs) from CCSM3 and CSIRO with respect to precipitation into 0.1 degree (about 11 km) spatial grid over study regions. The spatially archived hydro-climate data sets such as Willmott, GsMap and APHRODITE datasets were used for MOS corrections by means of monthly climatology between observations and downscaled values. Precipitation values downscaled in this study were validated against ground observations and then future climate simulation results on precipitation were evaluated for the projections.