• Journal of Environmental Impact Assessment
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• v.19 no.5
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• pp.465-473
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• 2010

This study was carried out to investigate the effect of EFDC hydrodynamic result on the WASP7.3 water quality modeling result in accordance with the change of number of grid for the dam reservoir to be constructed. The simulated flow and BOD, T-N and T-P loads by the HSPF watershed model was used for boundary conditions and the hydrodynamic modeling results was linked with WASP model to predict future water quality after dam construction. The scenarios for EFDC modeling were composed of Scenario 1(141 grid cells) and Scenario 2(568 grid cells). The results of Scenario 2 showed that BOD, T-N, T-P and Chl-a concentrations were decreased 0.073mg/L(8.5%), 0.032mg/L(2.6%), 0.003mg/L(6.8%), 0.644mg/L(4.2%) compared with those of Scenario 1, respectively. As number of grid cell increased, water quality concentrations were decreased and also it caused the longer running time. Therefore, this study suggests that the consideration of the geometry of water body is more important than the number of grid cells for the prediction of water quality of a dam reservoir in EIA.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.540-545
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• 2005

Large scale projects of sea-land reclamation have been practiced mainly to enlarge farmland in Korea. Most projects produced estuarine reservoir with dike construction, which might result in water quality problems due to block of natural flowing of stream water to the sea. Applicability of a widely accepted watershed-based water quality assessment tool (BASINS) and its associated watershed model was evaluated on the Hwaong watershed in Korea. BASINS was found to be a convenient and powerful tool for assessment of watershed characteristics, and provided various tools to delineate the watershed into land segments and river reaches, reclassify land use, and parameterize for HSPF simulation. WASP5 is a general purpose modeling system for assessing the fate and transport of conventional and toxic pollutants in surface water bodies. This study involved selection and linkage of available models to be used as a tool in evaluating the effects of BMPs for control on reservoir water quality. Overall,.Linkage of BASINS/HSPF and WASP5 was applicable and found to be a powerful tool in pollutant loading estimation from the watershed and reservoir, and its use is recommended.

• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.33-45
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• 2018

In this study, we discussed the application of Watershed model and Load Duration Curves (LDC) in Total Water Load Management System. The Flow Duration Curves (FDC) and the LDC were generated using the results of the daily HSPF model and analyzed on monthly or yearly flow duration variability, and non-point pollutant discharge loads by entire flow conditions. As a result of the calibration and verification of the HSPF model, both the flow and the water quality were appropriately simulated. The simulated values were used to generate the Flow Duration Curve and the Load Duration Curve, and then the excess rate by entire flow conditions was analyzed. The point and non-point pollutant discharge loads for entire flow conditions were calculated. It is possible to evaluate the variability of water quality in specific flow duration through the curves reflecting the flow duration variability and to confirm the characteristics of the pollutant source. For a more scientific Total Water Load Management System, it is necessary to switch from a current system to a system that can take into account the entire flow conditions. For this, the application of the watershed model and load duration curve is considered to be the best alternative.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.527-531
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• 2004

본 연구에서는 미국 환경청에서 개발하여 유역 오염총량관리를 위한 수질모형으로 이용되고 있는 HSPF 모형을 선정하여 발안 $HP\#6$ 시험유역을 내상으로 모형의 적용성을 분석하였다. HSPF 모형을 이용하여 $HP\#6$ 시험유역에서 모형의 보정기간인 1996년부터 1997년까지 유출량을 모의한 겉과, RMSE는 2.1mm, RMAE는 0.4mm, $R^2$는 0.92로 모의되었으며, 모형의 검정기간인 1999년부터 2000년의 모의 길과 RMSE는 6.03mm, RMAE는 0.49mm, $R^2$는 0.84로 모의되었다. 총질소에 대한 모형의 보정결과 RMSE는 0.086kg/ha/day, RMAE는 0.534kg/ha/day, $R^2$는 0.812로 나타났으며, 모형의 검정결과 RMSE는 0.326kg/ha/day, RMAE는 0.708kg/ha/day, $R^2$는 0.427로 분석되었다. 총인에 대한 모형의 보정결과 RMSE는 0.0117 kg/ha/day, RMAE는 0.622kg/ha/day, $R^2$는 0.70으로 모의되었으며, 모형의 검정결과 RMSE는 0.063kg/ha/day, RMAE는 2.269kg/ha/day, $R^2$는 0.756으로 분석되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.35-35
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• 2018

본 연구의 목적은 한강유역을 대상으로 다중 GCMs (General Circulation Models)을 이용하여 장기유출량을 분석하는 데 있다. 기후변화 전망을 분석하기 위해 총 13개의 GCMs을 선정하여 사용하였다. SDQDM (Spatial Disaggregation-Quantile Delta Mapping) 방법을 이용하여 GCMs을 60개 종관기상관측장비 (Automated Synoptic Observing System, ASOS)에 대해 상세화하였다. GCMs은 총 6개의 변수(강수, 최고 기온, 최저기온, 풍속, 상대습도, 일사량)를 제공하였다. 장기유출량 분석은 투수지역과 불투수지역을 모두 고려할 수 있는 HSPF 모형을 선정하여 수행하였다. 장기유출량의 공간적인 범위는 한강유역의 16개 중권역을 기준으로 선정하였고, 시간적인 범위는 과거 기준 기간 (Reference period: 1976-2005), 미래 3개 기간 (Near future period: 2011-2040, Mid-century period: 2041-2070, Distance future period: 2071-2099)으로 30년 단위로 구분하여 선정하였다. 본 연구는 13개의 GCM을 사용하여 추정된 장기유출량의 연간 및 계절적 평균과 변동성을 분석하였다. 본 연구에서 HSPF 모형을 활용하여 분석한 결과는 복잡한 한강유역의 특성을 적절히 반영하여, 기후변화에 따른 수자원 계획 및 통합 유역 관리를 수립하기 위한 기초 자료로 활용될 수 있을 것이라 사료된다.

• Journal of Korea Water Resources Association
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• v.55 no.10
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• pp.823-833
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• 2022

This study aims to improve the runoff modeling accuracy of a basin using Hydrological Simulation Program-FORTRAN (HSPF) model by considering nonhomogeneous characteristics of a basin. By entering classified values according to the various types of land cover and soil to the parameters in HSPF-roughness coefficient (NSUR), infiltration (INFILT), and evapotranspiration (LZETP)- the heterogeneity of the Yongdam Dam basin was reflected in the model. The results were analyzed and compared with the one where the parameters were set as a single value throughout the basin. The flow rate and water quality simulation results showed improved results when classified parameters were used by land cover and soil type than when single values were used. The parameterization changed not only the flow rate, but also the composition ratio of each hydrologic components such as surface runoff, baseflow, and evapotranspiration, which shows the impact of the value set to a parameter on the entire hydrological process. This implies the importance of considering the heterogeneous characteristics of the land cover and soil of the basin when setting the parameters in a model.

• Journal of Korean Society on Water Environment
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• v.30 no.6
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• pp.673-682
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• 2014

A watershed model was constructed using Hydrological Simulation Program Fortran to predict the water temperature at major tributaries of Nakdong River basin, Korea. Water temperature is one of the most fundamental indices used to determine the nature of an aquatic environment. Most processes of an aquatic environment such as saturation level of dissolved oxygen, the decay rate of organic matter, the growth rate of phytoplankton and zooplankton are affected by temperature. The heat flux to major reservoirs and tributaries was analyzed to simulate water temperature accurately using HSPF model. The annual mean heat flux of solar radiation was estimated to $150{\sim}165W/m^2$, longwave radiation to $-48{\sim}-113W/m^2$, evaporative heat loss to $-39{\sim}-115W/m^2$, sensible heat flux to $-13{\sim}-22W/m^2$, precipitation heat flux to $2{\sim}4W/m^2$, bed heat flux to $-24{\sim}22W/m^2$ respectively. The model was calibrated at major reservoir and tributaries for a three-year period (2008 to 2010). The deviation values (Dv) of water temperature ranged from -6.0 to 3.7%, Nash-Sutcliffe efficiency(NSE) of 0.88 to 0.95, root mean square error(RMSE) of $1.7{\sim}2.8^{\circ}C$. The operational water temperature forecasting results presented in this study were in good agreement with measured data and had a similar accuracy with model calibration results.

• Journal of Korean Society on Water Environment
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• v.29 no.2
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• pp.212-222
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• 2013

A watershed model was constructed using Hydrological Simulation Program Fortran to quantitatively predict the stream flows at major tributaries of Nakdong River basin, Korea. The entire basin was divided into 32 segments to effectively account for spatial variations in meteorological data and land segment parameter values of each tributary. The model was calibrated at ten tributaries including main stream of the river for a three-year period (2008 to 2010). The deviation values (Dv) of runoff volumes for operational stream flow forecasting for a six month period (2012.1.2 to 2012.6.29) at the ten tributaries ranged from -38.1 to 23.6%, which is on average 7.8% higher than those of runoff volumes for model calibration (-12.5 to 8.2%). The increased prediction errors were mainly from the uncertainties of numerical weather prediction modeling; nevertheless the stream flow forecasting results presented in this study were in a good agreement with the measured data.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.5
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• pp.41-54
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• 2018

A method to account a detention in a rice paddy field in hydrologic modeling was tested at plot and watershed scales. Hydrologic Simulation Program - Fortran (HSPF) and its one of surface runoff modeling method, i.e Surface-Ftable, were used to simulate a inundated condition in a rice paddy culture for a study plot and basins in Saemangeum watershed. Surface-Ftable in HSPF defines surface runoff ratio with respect to surface water depth in a pervious land segment, which can be implemented to the feature of water management in a rice paddy field. A Surface-Ftable for paddy fields in Saemangeum watershed was developed based on the study paddy field monitoring data from 2013 to 2014, and was applied to Jeonju-chun and Jeongeup-chun basins which comprise 12% and 22% of paddy fields in the basins, respectively. Four gaging stations were used to calibrate and validate the watershed models for the period of 2009 and 2013. Model performed 7.13% and 9.68% in PBIAS, and 0.94 and 0.90 in monthly NSE during model calibrations at Jeonju and Jeongeup stations, respectively, while the models were validated its applicability at Hyoja and Gongpyung stations. The comparison of results with and without considering detention effect of paddy fields confirmed the validity of the Surface-Ftable method in modeling watersheds containing rice paddy fields.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.5
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• pp.358-363
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• 2009

The HSPF (Hydrological Simulation Program-Fortran) model was applied to the Kyoungan stream watershed to analyze effects of watershed management plans on receiving water qualities. Utilizing BASINS 3.1 GIS program, the Kyoungan stream watershed was divided into 57 sub-basins and model input parameters were obtained, from DEM (Digital Elevation Model), land use type, stream map, and wastewater treatment facilities, etc.. The hydrologic module of the model was validated based on the measured meteorological data and stream flow data. Then the model was calibrated and verified against the field measurements of water qualities, including temperature, DO, BOD, $NO_3-N$, $NH_3-N$, Org-N, TN and TP. In most cases, there were reasonable agreements between measurements and predictions. The validated model was used to analyze the water quality improvements in the main stream of Kyoungan stream according to the watershed management plans in sub-basins, which are three different scenarios: water quality improvement in tributaries through watershed management activities, expansion and up-grade of wastewater treatment plants, and application of first and second scenarios together. It was concluded that expansion and upgrade of wastewater treatment plants would be more effective than watershed management activities. In order to improve water qualities to the satisfactory level, both watershed management and point source control must be required in the Kyoungan stream.