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Jichul Ryu
Research Strategy and Planning Division, National Institute of Environmental Research, Incheon 22689, Korea

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Journal article
Published: 26 June 2021 in Sustainability
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This study aimed to estimate pollutant unit loads for different landuses and pollutants that reflected long-term runoff characteristics of nonpoint source (NPS) pollutants and recent environmental changes. During 2008–2014, 2026 rainfall events were monitored. The average values of antecedent dry days, total rainfall, rainfall intensity, rainfall duration, runoff duration, and runoff coefficient for each landuse were 3.8–5.9 d, 35.2–65.0 mm, 2.9–4.1 mm/h, 12.5–20.4 h, 12.4–27.9 h, and 0.24–0.45, respectively. Uplands (UL) exhibited high suspended solids (SS, 606.2 mg/L), total nitrogen (TN, 7.38 mg/L), and total phosphorous (TP, 2.27 mg/L) levels, whereas the runoff coefficient was high in the building sites (BS), with a high impervious surface ratio. The event mean concentration (EMC) for biological oxygen demand (BOD) was the highest in BS (8.0 mg/L), while the EMC was the highest in BS (in the rainfall range 50 mm). The unit loads for BOD (1.49–17.76 kg/km2·d), TN (1.462–10.147 kg/km2·d), TP (0.094–1.435 kg/km2·d), and SS (15.20–327.70 kg/km2·d) were calculated. The findings can be used to manage NPS pollutants and watershed environments and implement relevant associated management systems.

ACS Style

Jiyeon Choi; Baekyung Park; Jinsun Kim; Soyoung Lee; Jichul Ryu; Kyunghyun Kim; Yongseok Kim. Determination of NPS Pollutant Unit Loads from Different Landuses. Sustainability 2021, 13, 7193 .

AMA Style

Jiyeon Choi, Baekyung Park, Jinsun Kim, Soyoung Lee, Jichul Ryu, Kyunghyun Kim, Yongseok Kim. Determination of NPS Pollutant Unit Loads from Different Landuses. Sustainability. 2021; 13 (13):7193.

Chicago/Turabian Style

Jiyeon Choi; Baekyung Park; Jinsun Kim; Soyoung Lee; Jichul Ryu; Kyunghyun Kim; Yongseok Kim. 2021. "Determination of NPS Pollutant Unit Loads from Different Landuses." Sustainability 13, no. 13: 7193.

Journal article
Published: 05 July 2019 in Water
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Due to the growing significance of water quality degradation by non-point source (NPS) pollution, regions in which NPS management is required should be designated as the management areas. Relevant management measures should be established to control water quality items related to degradation. It is advantageous that the area where the water environment is negatively affected by NPS is provided with legal grounds for NPS management, namely the designation of an NPS management area. This is because if it is designated as an NPS management area, the government can support the budget necessary for the installation of non-point pollution reduction facilities. In order to effectively utilize the limited budget, it is necessary to select and concentrate the area that should be managed first in the NPS management area. For the efficiency of the NPS pollution management within a management region, priority locations or key management sub-regions should be determined to implement differential management plans. Also, in selecting priority management regions, evaluation factors that can reflect the effects of NPS, such as the water quality target excess ratio in the mid-level region (or the total maximum daily load (TMDL) management) which includes the target region (low-level region), the NPS load in land, and non-permeable area ratio, should be quantified and the management order should be defined. Since NPS has local characteristics, the management items should be determined based on turbidity, suspended solid (SS), or total phosphorus (TP) that affect the local water quality. When the water environment is polluted due to non-point pollutants, various materials such as turbidity, SS, TP, Escherichia coli, and heavy metals can be set as management items according to local characteristics. However, the most important items to be managed are turbidity, SS, and TP, because if the solid (SS) is present in the water, which is highly turbid and does not sink easily, people can feel unpleasant and feel that the water is not clean, even if they do not analyze the water quality. In addition, in the case of TP, nutrients accumulated in the land are introduced into the river by rainfall, causing eutrophication. People feel uncomfortable because it changes the water color. Other pollutants can only be found to be contaminated after water quality analysis is performed. The water quality target of the management items should be set realistically, based on the situation of the watershed by considering the watershed model, management flow, NPS pollutant reduction plan, the river flow in the management area, and load. All these reflect the characteristics of the region. To evaluate whether the water quality target is achieved after NPS management, a method similar to the one to set the water quality target should be used to review the performance of the management plan. This study introduces specific examples of key factors in establishing an NPS management plan,...

ACS Style

Jae Hong Park; Jichul Ryu; Dong Seok Shin; Jae Kwan Lee. Methodology for Determining the Key Factors for Non-Point Source Management. Water 2019, 11, 1381 .

AMA Style

Jae Hong Park, Jichul Ryu, Dong Seok Shin, Jae Kwan Lee. Methodology for Determining the Key Factors for Non-Point Source Management. Water. 2019; 11 (7):1381.

Chicago/Turabian Style

Jae Hong Park; Jichul Ryu; Dong Seok Shin; Jae Kwan Lee. 2019. "Methodology for Determining the Key Factors for Non-Point Source Management." Water 11, no. 7: 1381.

Journal article
Published: 23 October 2018 in Ecological Engineering
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Accurate analysis of water flow (streamflow and baseflow) is important for accurate water resources management. For accurate water resources management, modeled surface and groundwater hydrology should be calibrated simultaneously. The objectives of this study are: 1) to develop and provide an efficient flow calibration method (EFCM) for accurate baseflow estimation by combining the Sequential Uncertainty Fitting algorithm version 2 (SUFI-2) and modified SWAT 2012 code and 2) to evaluate the performance of the EFCM for streamflow and baseflow estimation. Both streamflow and baseflow estimated using the EFCM performed well based on three model evaluation methods (i.e., NSE, R2, and PBIAS). Thus, the EFCM would be a practical method for accurate water resources management by calibrating baseflow accurately as well as streamflow at a watershed scale. This study can be used as a data-driven model groundwater modeling because the baseflow-related parameters (i.e., groundwater recharge and hydraulic conductivity) calibrated in this study can be used as a set of input data (initial parameter values) in computer-based numerical groundwater models.

ACS Style

Won Seok Jang; Bernard Engel; Jichul Ryu. Efficient flow calibration method for accurate estimation of baseflow using a watershed scale hydrological model (SWAT). Ecological Engineering 2018, 125, 50 -67.

AMA Style

Won Seok Jang, Bernard Engel, Jichul Ryu. Efficient flow calibration method for accurate estimation of baseflow using a watershed scale hydrological model (SWAT). Ecological Engineering. 2018; 125 ():50-67.

Chicago/Turabian Style

Won Seok Jang; Bernard Engel; Jichul Ryu. 2018. "Efficient flow calibration method for accurate estimation of baseflow using a watershed scale hydrological model (SWAT)." Ecological Engineering 125, no. : 50-67.

Journal article
Published: 21 September 2017 in Water Supply
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The Long-term Hydrologic Impact Assessment Model with Asymptotic Curve Number Regression Equation and Water Quality model (L-THIA ACN-WQ) has been developed to simulate streamflow as well as instream water quality using fewer parameters, compared to other watershed models. However, since model input parameters (i.e. hydraulic response unit (HRU) map, stream network, database (DB), etc.) should be built by user manually, it is difficult to use the model for a nonprofessional or environmental policy decision-maker. In addition, it is difficult to analyze model outputs in time and space because the model does not provide geographic information system (GIS) information for the simulation results. To overcome the limitations, an advanced version of L-THIA ACN-WQ system which is based on ArcGIS interface was developed in this study. To evaluate the applicability of the developed system, it was applied to the Banbyeon A watershed in which total maximum daily load (TMDL) has been implemented. The required model input datasets were automatically collected in the system, and stream flow, T-N and T-P pollutant loads were simulated for the watershed. Furthermore, flow duration curve (FDC) and load duration curve (LDC) were generated to analyze hot spot areas in the system through automatic processes included in the system. The system can establish the model input data easily, automatically provide the graphs of FDC and LDC, and provide hot spot areas which indicate high pollutant loads. Therefore, this system can be useful in establishing various watershed management plans.

ACS Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Gwanjae Lee; Kwangsik Yoon; Yong Seok Kim; Kyoung Jae Lim. Development and evaluation of ArcGIS based watershed-scale L-THIA ACN-WQ system for watershed management. Water Supply 2017, 18, 1206 -1221.

AMA Style

Jichul Ryu, Won Seok Jang, Jonggun Kim, Gwanjae Lee, Kwangsik Yoon, Yong Seok Kim, Kyoung Jae Lim. Development and evaluation of ArcGIS based watershed-scale L-THIA ACN-WQ system for watershed management. Water Supply. 2017; 18 (4):1206-1221.

Chicago/Turabian Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Gwanjae Lee; Kwangsik Yoon; Yong Seok Kim; Kyoung Jae Lim. 2017. "Development and evaluation of ArcGIS based watershed-scale L-THIA ACN-WQ system for watershed management." Water Supply 18, no. 4: 1206-1221.

Journal article
Published: 30 November 2016 in Journal of Korean Society on Water Environment
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ACS Style

Pilju Kwon; Jichul Ryu; Ng Jun Lee; Jeongho Han; Yunsoo Sung; Kyoung Jae Lim; Ki-Sung Kim. Comparative Analysis of Land Use Change Model at Gapcheon Watershed. Journal of Korean Society on Water Environment 2016, 32, 552 -561.

AMA Style

Pilju Kwon, Jichul Ryu, Ng Jun Lee, Jeongho Han, Yunsoo Sung, Kyoung Jae Lim, Ki-Sung Kim. Comparative Analysis of Land Use Change Model at Gapcheon Watershed. Journal of Korean Society on Water Environment. 2016; 32 (6):552-561.

Chicago/Turabian Style

Pilju Kwon; Jichul Ryu; Ng Jun Lee; Jeongho Han; Yunsoo Sung; Kyoung Jae Lim; Ki-Sung Kim. 2016. "Comparative Analysis of Land Use Change Model at Gapcheon Watershed." Journal of Korean Society on Water Environment 32, no. 6: 552-561.

Journal article
Published: 31 July 2016 in Journal of The Korean Society of Agricultural Engineers
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ACS Style

Jichul Ryu; Ha-Sun Hwang; Sung-Jun Lee; Eun Kyoung Kim; Yong Seok Kim; Donghyuk Kum; Kyoung Jae Lim; Younghun Jung. Development of Desktop-Based LDC Evaluation System for Effectiveness TMDLs. Journal of The Korean Society of Agricultural Engineers 2016, 58, 67 -74.

AMA Style

Jichul Ryu, Ha-Sun Hwang, Sung-Jun Lee, Eun Kyoung Kim, Yong Seok Kim, Donghyuk Kum, Kyoung Jae Lim, Younghun Jung. Development of Desktop-Based LDC Evaluation System for Effectiveness TMDLs. Journal of The Korean Society of Agricultural Engineers. 2016; 58 (4):67-74.

Chicago/Turabian Style

Jichul Ryu; Ha-Sun Hwang; Sung-Jun Lee; Eun Kyoung Kim; Yong Seok Kim; Donghyuk Kum; Kyoung Jae Lim; Younghun Jung. 2016. "Development of Desktop-Based LDC Evaluation System for Effectiveness TMDLs." Journal of The Korean Society of Agricultural Engineers 58, no. 4: 67-74.

Article
Published: 25 July 2016 in Irrigation and Drainage
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The Natural Resources Conservation Service-Curve Number (NRCS-CN) method has been used widely for estimation of direct runoff. However, the determination methods of CN values for land covers from the National Engineering Handbook Chapter 4 (NEH-4) are inadequate due to uncertainty raised in determining the of the hydrologic soil group, which could change from reported soil survey data due to soil compaction and other human activities. To overcome these drawbacks, an asymptotic CN (ACN) regression equation for the relationship between measured streamflow and rainfall for gauged river basins (ACN-RB) was developed and used in various studies. The ACN-RB determines various CN values depending on the amount of rainfall in an event. The ACN-RB has limitations in application to ungauged river basin because the ACN-based CN values do not consider various land covers. Accordingly, 13 land cover-based asymptotic CN regression equations (LC-ACN-REs) were developed and evaluated in this study by comparing estimated direct runoff with measured data. The estimated direct runoff using the LC-ACN-REs, which were classified as “standard types”, matched observed direct runoff well, as evidenced by a Nash-Sutcliff efficiency (NSE) value of 0.78 for Jungrang A basin and a NSE value of 0.73 for Tancheon A basin. Copyright © 2016 John Wiley & Sons, Ltd. La méthode des curver numbers du service natural conservation des ressources (NRCS-CN) a été largement utilisée pour l'estimation de ruissellement direct. Cependant, les méthodes de détermination des valeurs de CN données par le manuel national de l'ingénierie (National Engineering Handbook Chapitre 4 ; NEH-4) sont inadéquates en raison de l'incertitude dans la détermination du groupe hydrologique de sols ; cette classification est. de nature à évoluer en raison des tassements du sol et d'autres activités humaines. Afin de remédier à ces inconvénients, une équation de régression asymptotique du CN pour la relation entre le débit mesuré et les précipitations a été élaborée pour des bassins hydrographiques calibrés (ACN-RB) et utilisée dans diverses études. L'ACN-RB détermine différentes valeurs CN selon la quantité de précipitations au cours d'un épisode. L'ACN-RB a aussi ses limites dans l'application aux bassins non jaugés parce que ces valeurs CN ne considèrent pas la diversité des couvertures terrestres. En conséquence, les équations de régression (LC-ACN-RE) de treize couvertures terrestres ont été proposées et évaluées dans cette étude, en comparant le ruissellement direct estimé avec les données mesurées. Les ruissellements directs estimés, qui ont été proposés comme types standard, sont bien en accord avec les valeurs observées, comme en témoignent les coefficients de Nash-Sutcliff obtenus pour deux bassins, de 0,78 pour le bassin de Jungrang et de 0,73 pour le bassin de Tancheon. Copyright © 2016 John Wiley & Sons, Ltd.

ACS Style

Jichul Ryu; Younghun Jung; Dong Soo Kong; Bae Kyung Park; Yong Seok Kim; Bernard A. Engel; Kyoung Jae Lim. Approach of Land Cover Based Asymptotic Curve Number Regression Equation to Estimate Runoff. Irrigation and Drainage 2016, 65, 94 -104.

AMA Style

Jichul Ryu, Younghun Jung, Dong Soo Kong, Bae Kyung Park, Yong Seok Kim, Bernard A. Engel, Kyoung Jae Lim. Approach of Land Cover Based Asymptotic Curve Number Regression Equation to Estimate Runoff. Irrigation and Drainage. 2016; 65 ():94-104.

Chicago/Turabian Style

Jichul Ryu; Younghun Jung; Dong Soo Kong; Bae Kyung Park; Yong Seok Kim; Bernard A. Engel; Kyoung Jae Lim. 2016. "Approach of Land Cover Based Asymptotic Curve Number Regression Equation to Estimate Runoff." Irrigation and Drainage 65, no. : 94-104.

Correction
Published: 21 July 2016 in Water
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The authors wish to make the following corrections to this paper [1]: The author name “Bernard A. Engle” should be “Bernard A. Engel”

ACS Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Joong Dae Choi; Bernard A. Engel; Jae E. Yang; Kyoung Jae Lim. Correction: Ryu, J., et al. Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation. Water 2016, 8, 153. Water 2016, 8, 307 .

AMA Style

Jichul Ryu, Won Seok Jang, Jonggun Kim, Joong Dae Choi, Bernard A. Engel, Jae E. Yang, Kyoung Jae Lim. Correction: Ryu, J., et al. Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation. Water 2016, 8, 153. Water. 2016; 8 (7):307.

Chicago/Turabian Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Joong Dae Choi; Bernard A. Engel; Jae E. Yang; Kyoung Jae Lim. 2016. "Correction: Ryu, J., et al. Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation. Water 2016, 8, 153." Water 8, no. 7: 307.

Journal article
Published: 15 July 2016 in Water
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The Long Term Hydrologic Impact Assessment (L-THIA) model was previously improved by incorporating direct runoff lag time and baseflow. However, the improved model, called the L-THIA asymptotic curve number (ACN) model cannot simulate pollutant loads from a watershed or instream water quality. In this study, a module for calculating pollutant loads from fields and through stream networks was developed, and the L-THIA ACN model was combined with the QUAL2E model (The enhanced stream water quality model) to predict instream water quality at a watershed scale. The new model (L-THIA ACN-WQ) was applied to two watersheds within the Korean total maximum daily loads management system. To evaluate the model, simulated results of total nitrogen (TN) and total phosphorus (TP) were compared with observed water quality data collected at eight-day intervals. Between simulated and observed data for TN pollutant loads in Dalcheon A watershed, the R2 and Nash–Sutcliffe efficiency (NSE) were 0.81 and 0.79, respectively, and those for TP were 0.79 and 0.78, respectively. In the Pyungchang A watershed, the R2 and NSE were 0.66 and 0.64, respectively, for TN and both statistics were 0.66 for TP, indicating that model performed satisfactorily for both watersheds. Thus, the L-THIA ACN-WQ model can accurately simulate streamflow, instream pollutant loads, and water quality.

ACS Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Younghun Jung; Bernard A. Engel; Kyoung Jae Lim. Development of Field Pollutant Load Estimation Module and Linkage of QUAL2E with Watershed-Scale L-THIA ACN Model. Water 2016, 8, 292 .

AMA Style

Jichul Ryu, Won Seok Jang, Jonggun Kim, Younghun Jung, Bernard A. Engel, Kyoung Jae Lim. Development of Field Pollutant Load Estimation Module and Linkage of QUAL2E with Watershed-Scale L-THIA ACN Model. Water. 2016; 8 (7):292.

Chicago/Turabian Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Younghun Jung; Bernard A. Engel; Kyoung Jae Lim. 2016. "Development of Field Pollutant Load Estimation Module and Linkage of QUAL2E with Watershed-Scale L-THIA ACN Model." Water 8, no. 7: 292.

Journal article
Published: 16 April 2016 in Water
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In this study, 52 asymptotic Curve Number (CN) regression equations were developed for combinations of representative land covers and hydrologic soil groups. In addition, to overcome the limitations of the original Long-term Hydrologic Impact Assessment (L-THIA) model when it is applied to larger watersheds, a watershed-scale L-THIA Asymptotic CN (ACN) regression equation model (watershed-scale L-THIA ACN model) was developed by integrating the asymptotic CN regressions and various modules for direct runoff/baseflow/channel routing. The watershed-scale L-THIA ACN model was applied to four watersheds in South Korea to evaluate the accuracy of its streamflow prediction. The coefficient of determination (R2) and Nash–Sutcliffe Efficiency (NSE) values for observed versus simulated streamflows over intervals of eight days were greater than 0.6 for all four of the watersheds. The watershed-scale L-THIA ACN model, including the asymptotic CN regression equation method, can simulate long-term streamflow sufficiently well with the ten parameters that have been added for the characterization of streamflow.

ACS Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Joong Dae Choi; Bernard A. Engel; Jae E. Yang; Kyoung Jae Lim. Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation. Water 2016, 8, 153 .

AMA Style

Jichul Ryu, Won Seok Jang, Jonggun Kim, Joong Dae Choi, Bernard A. Engel, Jae E. Yang, Kyoung Jae Lim. Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation. Water. 2016; 8 (4):153.

Chicago/Turabian Style

Jichul Ryu; Won Seok Jang; Jonggun Kim; Joong Dae Choi; Bernard A. Engel; Jae E. Yang; Kyoung Jae Lim. 2016. "Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation." Water 8, no. 4: 153.

Journal article
Published: 31 March 2016 in Journal of Korean Society on Water Environment
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Evaluation of SRI Water Management on the Reduction of Irrigation Supply and NPS Pollution in Paddies EMCs;Irrigation water reduction;NPS pollution;System of rice intensification;SRI; Monitored data (rainfall runoff and water quality) from 4 different paddy sites over 3 years were compared to analyze the effect of irrigation water management on irrigation supply and rainfall runoff quality in Korea. The system of rice intensification water management was adopted at one site (SRI) while the conventional water management method was used for rice culture at the other three sites (CT, SD and HD). The soil texture at SRI, CT and SD was sandy loam while that at HD was silt loam. The average reduction of irrigation supply at SRI compared with CT, SD and HD during the 3 years studied was 49%, 51% and 55%, respectively. The average event mean concentration (EMC) at SRI compared with that at CT, SD and HD was decreased by 35% (BOD), 44% (COD), 47% (SS), 19% (TN) and 38% (TP). The correlation between rainfall runoff and the measured non-point source (NPS) pollutants was very good in general. The comparison revealed that SRI water management significantly reduced both irrigation supply and EMC in rainfall runoff. Paddy NPS pollution was closely related to factors that induce runoff such as rainfall and irrigation supply. It was concluded that SRI management could be an effective and practical option to cope with both water shortage due to climate change and water quality improvement in rural watersheds. However, further studies are recommended in large irrigation districts for use in the development and implementation of NPS pollution policies since the data was collected from field sized paddies.

ACS Style

Jiyeon Seo; Baekyung Park; Woonji Park; Kwangsik Yoon; Dongho Choi; Yongseok Kim; Jichul Ryu; Joongdae Choi. Evaluation of SRI Water Management on the Reduction of Irrigation Supply and NPS Pollution in Paddies. Journal of Korean Society on Water Environment 2016, 32, 183 -190.

AMA Style

Jiyeon Seo, Baekyung Park, Woonji Park, Kwangsik Yoon, Dongho Choi, Yongseok Kim, Jichul Ryu, Joongdae Choi. Evaluation of SRI Water Management on the Reduction of Irrigation Supply and NPS Pollution in Paddies. Journal of Korean Society on Water Environment. 2016; 32 (2):183-190.

Chicago/Turabian Style

Jiyeon Seo; Baekyung Park; Woonji Park; Kwangsik Yoon; Dongho Choi; Yongseok Kim; Jichul Ryu; Joongdae Choi. 2016. "Evaluation of SRI Water Management on the Reduction of Irrigation Supply and NPS Pollution in Paddies." Journal of Korean Society on Water Environment 32, no. 2: 183-190.

Journal article
Published: 16 December 2015 in Paddy and Water Environment
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To secure accuracy in the Soil and Water Assessment Tool (SWAT) simulation for various hydrology and water quality studies, calibration and validation should be performed. When calibrating and validating the SWAT model with measured data, the Nash–Sutcliffe efficiency (NSE) is widely used, and is also used as a goal function of auto-calibration in the current SWAT model (SWAT ver. 2009). However, the NSE value has been known to be influenced by high values within a given dataset, at the cost of the accuracy in estimated lower flow values. Furthermore, the NSE is unable to consider direct runoff and baseflow separately. In this study, the existing SWAT auto-calibration was modified with direct runoff separation and flow clustering calibration, and current and modified SWAT auto-calibration were applied to the Soyanggang-dam watershed in South Korea. As a result, the NSE values for total streamflow, high flow, and low flow groups in direct runoff, and baseflow estimated through modified SWAT auto-calibration were 0.84, 0.34, 0.09, and 0.90, respectively. The NSE values of current SWAT auto-calibration were 0.83, 0.47, −0.14, and 0.90, respectively. As shown in this study, the modified SWAT auto-calibration shows better calibration results than current SWAT auto-calibration. With these capabilities, the SWAT-estimated flow matched the measured flow data well for the entire flow regime. The modified SWAT auto-calibration module developed in this study will provide a very efficient tool for the accurate simulation of hydrology, sediment transport, and water quality with no additional input datasets.

ACS Style

Hyunwoo Kang; Jongpil Moon; Yongchul Shin; Jichul Ryu; Dong Hyuk Kum; Chunhwa Jang; Joongdae Choi; Dong Soo Kong; Kyoung Jae Lim. Modification of SWAT auto-calibration for accurate flow estimation at all flow regimes. Paddy and Water Environment 2015, 14, 499 -508.

AMA Style

Hyunwoo Kang, Jongpil Moon, Yongchul Shin, Jichul Ryu, Dong Hyuk Kum, Chunhwa Jang, Joongdae Choi, Dong Soo Kong, Kyoung Jae Lim. Modification of SWAT auto-calibration for accurate flow estimation at all flow regimes. Paddy and Water Environment. 2015; 14 (4):499-508.

Chicago/Turabian Style

Hyunwoo Kang; Jongpil Moon; Yongchul Shin; Jichul Ryu; Dong Hyuk Kum; Chunhwa Jang; Joongdae Choi; Dong Soo Kong; Kyoung Jae Lim. 2015. "Modification of SWAT auto-calibration for accurate flow estimation at all flow regimes." Paddy and Water Environment 14, no. 4: 499-508.

Journal article
Published: 30 November 2015 in Journal of Korean Society on Water Environment
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Yunsoo Sung; Jae E Yang; Sung Chul Kim; Jichul Ryu; Wonseok Jang; Donghyuk Kum; Kyoung Jae Lim. Development of Composite Soil Quality Index Evaluation System based on Web GIS. Journal of Korean Society on Water Environment 2015, 31, 693 -699.

AMA Style

Yunsoo Sung, Jae E Yang, Sung Chul Kim, Jichul Ryu, Wonseok Jang, Donghyuk Kum, Kyoung Jae Lim. Development of Composite Soil Quality Index Evaluation System based on Web GIS. Journal of Korean Society on Water Environment. 2015; 31 (6):693-699.

Chicago/Turabian Style

Yunsoo Sung; Jae E Yang; Sung Chul Kim; Jichul Ryu; Wonseok Jang; Donghyuk Kum; Kyoung Jae Lim. 2015. "Development of Composite Soil Quality Index Evaluation System based on Web GIS." Journal of Korean Society on Water Environment 31, no. 6: 693-699.

Journal article
Published: 30 May 2015 in Journal of Korean Society on Water Environment
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ACS Style

Donghyuk Kum; Younsik Park; Young Hun Jung; Min Hwan Shin; Jichul Ryu; Ji Hyung Park; Jae E Yang; Kyoung Jae Lim. Analysis of Rainfall-Runoff Characteristics on Bias Correction Method of Climate Change Scenarios. Journal of Korean Society on Water Environment 2015, 31, 241 -252.

AMA Style

Donghyuk Kum, Younsik Park, Young Hun Jung, Min Hwan Shin, Jichul Ryu, Ji Hyung Park, Jae E Yang, Kyoung Jae Lim. Analysis of Rainfall-Runoff Characteristics on Bias Correction Method of Climate Change Scenarios. Journal of Korean Society on Water Environment. 2015; 31 (3):241-252.

Chicago/Turabian Style

Donghyuk Kum; Younsik Park; Young Hun Jung; Min Hwan Shin; Jichul Ryu; Ji Hyung Park; Jae E Yang; Kyoung Jae Lim. 2015. "Analysis of Rainfall-Runoff Characteristics on Bias Correction Method of Climate Change Scenarios." Journal of Korean Society on Water Environment 31, no. 3: 241-252.

Journal article
Published: 30 March 2015 in Journal of The Korean Society of Agricultural Engineers
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ACS Style

Youn Shik Park; Ji Min Lee; Younghun Jung; Min Hwan Shin; Ji Hyung Park; Hasun Hwang; Jichul Ryu; Jangho Park; Ki-Sung Kim. Evaluation of Regression Models in LOADEST to Estimate Suspended Solid Load in Hangang Waterbody. Journal of The Korean Society of Agricultural Engineers 2015, 57, 37 -45.

AMA Style

Youn Shik Park, Ji Min Lee, Younghun Jung, Min Hwan Shin, Ji Hyung Park, Hasun Hwang, Jichul Ryu, Jangho Park, Ki-Sung Kim. Evaluation of Regression Models in LOADEST to Estimate Suspended Solid Load in Hangang Waterbody. Journal of The Korean Society of Agricultural Engineers. 2015; 57 (2):37-45.

Chicago/Turabian Style

Youn Shik Park; Ji Min Lee; Younghun Jung; Min Hwan Shin; Ji Hyung Park; Hasun Hwang; Jichul Ryu; Jangho Park; Ki-Sung Kim. 2015. "Evaluation of Regression Models in LOADEST to Estimate Suspended Solid Load in Hangang Waterbody." Journal of The Korean Society of Agricultural Engineers 57, no. 2: 37-45.

Journal article
Published: 30 January 2015 in Journal of Korean Society on Water Environment
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ACS Style

Youn Ho Choi; Donghuyk Kum; Jichul Ryu; Younghun Jung; Yong Seok Kim; Ji Hong Jeon; Ki Sung Kim; Kyoung Jae Lim. A Study of Total Nitrogen Pollutant Load through Baseflow Analysis at the Watershed. Journal of Korean Society on Water Environment 2015, 31, 55 -66.

AMA Style

Youn Ho Choi, Donghuyk Kum, Jichul Ryu, Younghun Jung, Yong Seok Kim, Ji Hong Jeon, Ki Sung Kim, Kyoung Jae Lim. A Study of Total Nitrogen Pollutant Load through Baseflow Analysis at the Watershed. Journal of Korean Society on Water Environment. 2015; 31 (1):55-66.

Chicago/Turabian Style

Youn Ho Choi; Donghuyk Kum; Jichul Ryu; Younghun Jung; Yong Seok Kim; Ji Hong Jeon; Ki Sung Kim; Kyoung Jae Lim. 2015. "A Study of Total Nitrogen Pollutant Load through Baseflow Analysis at the Watershed." Journal of Korean Society on Water Environment 31, no. 1: 55-66.

Research article
Published: 14 December 2014 in Advances in Meteorology
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We performed bias correction in future climate change scenarios to provide better accuracy of models through adaptation to future climate change. The proposed combination of the change factor (CF) and quantile mapping (QM) methods combines the individual advantages of both methods for adjusting the bias in global circulation models (GCMs) and regional circulation models (RCMs). We selected a study site in Songwol-dong, Seoul, Republic of Korea, to test and assess our proposed method. Our results show that the combined CF

ACS Style

Donghyuk Kum; Kyoung Jae Lim; Chun Hwa Jang; Jichul Ryu; Jae E. Yang; Seong Joon Kim; Dong Soo Kong; Younghun Jung. Projecting Future Climate Change Scenarios Using Three Bias-Correction Methods. Advances in Meteorology 2014, 2014, 1 -12.

AMA Style

Donghyuk Kum, Kyoung Jae Lim, Chun Hwa Jang, Jichul Ryu, Jae E. Yang, Seong Joon Kim, Dong Soo Kong, Younghun Jung. Projecting Future Climate Change Scenarios Using Three Bias-Correction Methods. Advances in Meteorology. 2014; 2014 (2):1-12.

Chicago/Turabian Style

Donghyuk Kum; Kyoung Jae Lim; Chun Hwa Jang; Jichul Ryu; Jae E. Yang; Seong Joon Kim; Dong Soo Kong; Younghun Jung. 2014. "Projecting Future Climate Change Scenarios Using Three Bias-Correction Methods." Advances in Meteorology 2014, no. 2: 1-12.

Journal article
Published: 31 August 2014 in Journal of Korean Society of Environmental Engineers
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Jichul Ryu; Donghyuk Kum; Dong Seok Shin; Ki Hong Ahn; Bae Kyung Park; Koung Jae Lim. Enhancement of HRSM4BMP Model to Simulate Sediment Reduction Efficiency Based on Watershed Scale. Journal of Korean Society of Environmental Engineers 2014, 36, 521 -527.

AMA Style

Jichul Ryu, Donghyuk Kum, Dong Seok Shin, Ki Hong Ahn, Bae Kyung Park, Koung Jae Lim. Enhancement of HRSM4BMP Model to Simulate Sediment Reduction Efficiency Based on Watershed Scale. Journal of Korean Society of Environmental Engineers. 2014; 36 (8):521-527.

Chicago/Turabian Style

Jichul Ryu; Donghyuk Kum; Dong Seok Shin; Ki Hong Ahn; Bae Kyung Park; Koung Jae Lim. 2014. "Enhancement of HRSM4BMP Model to Simulate Sediment Reduction Efficiency Based on Watershed Scale." Journal of Korean Society of Environmental Engineers 36, no. 8: 521-527.

Journal article
Published: 30 July 2014 in Journal of Korean Society on Water Environment
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Analysis of Baseflow Contribution to Streamflow at Several Flow Stations Baseflow;Direct runoff;Pollutant load;Separating baseflow;Streamflow; Streamflow is typically divided into two components that are direct runoff and baseflow, it is required to analyze and estimate behaviors of those two flow components to understand watershed characteristics so that watershed management plan can be effective in pollutant reductions. Since pollutant load behaviors in a stream or river are variable by flow component behaviors, best management practices need to be applied in a watershed based on the pollutant load behaviors varying with flow components. Thus, baseflow behaviors were analyzed separating baseflow from streamflow data collected from fifteen streamflow gaging stations in the 4 major river watersheds which are the Han river, Nakdong river, Guem river, and Yeongsan Somjin river watersheds. Moreover, precipitation trends throughout the 4 River Systems were investigated, thus daily precipitation data were collected from sixty-five locations. The Hank river watershed displayed the largest precipitation (925.2 mm) in summer but the lowest precipitation (71.8 mm) in winter, indicating the watershed has the most fluctuating precipitation characteristic. While the precipitation trends in the Four River Systems varied, a distinct feature in baseflow trends was not found, moreover baseflow percentages to streamflow were typically greater than 50% in the Four River Systems. As shown in this study, it would be expected significant amount of pollutants could be contributed to the stream in the form of baseflow at the watershed.

ACS Style

Youn Ho Choi; Youn Shik Park; Jichul Ryu; Dong June Lee; Yong Seok Kim; Joongdae Choi; Kyoung Jae Lim. Analysis of Baseflow Contribution to Streamflow at Several Flow Stations. Journal of Korean Society on Water Environment 2014, 30, 441 -451.

AMA Style

Youn Ho Choi, Youn Shik Park, Jichul Ryu, Dong June Lee, Yong Seok Kim, Joongdae Choi, Kyoung Jae Lim. Analysis of Baseflow Contribution to Streamflow at Several Flow Stations. Journal of Korean Society on Water Environment. 2014; 30 (4):441-451.

Chicago/Turabian Style

Youn Ho Choi; Youn Shik Park; Jichul Ryu; Dong June Lee; Yong Seok Kim; Joongdae Choi; Kyoung Jae Lim. 2014. "Analysis of Baseflow Contribution to Streamflow at Several Flow Stations." Journal of Korean Society on Water Environment 30, no. 4: 441-451.

Journal article
Published: 30 July 2014 in Journal of Korean Society on Water Environment
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ACS Style

Jichul Ryu; Ki Hong Ahn; Mideok Han; Hasun Hwang; JaeWan Choi; Yong Seok Kim; Kyoung Jae Lim. Evaluation and Application of CLUE-S Model for Spatio-Temporal Analysis of Future Land use Change in Total Water Pollution Load Management System. Journal of Korean Society on Water Environment 2014, 30, 418 -428.

AMA Style

Jichul Ryu, Ki Hong Ahn, Mideok Han, Hasun Hwang, JaeWan Choi, Yong Seok Kim, Kyoung Jae Lim. Evaluation and Application of CLUE-S Model for Spatio-Temporal Analysis of Future Land use Change in Total Water Pollution Load Management System. Journal of Korean Society on Water Environment. 2014; 30 (4):418-428.

Chicago/Turabian Style

Jichul Ryu; Ki Hong Ahn; Mideok Han; Hasun Hwang; JaeWan Choi; Yong Seok Kim; Kyoung Jae Lim. 2014. "Evaluation and Application of CLUE-S Model for Spatio-Temporal Analysis of Future Land use Change in Total Water Pollution Load Management System." Journal of Korean Society on Water Environment 30, no. 4: 418-428.