SWAT과 SATEEC 모형을 이용한 토양유실량 비교

박윤식 ( Park Younshik ),김종건 ( Kim Jonggun ),신용철 ( Shin Yongchul ),안재훈 ( Ahn Jaehun ),박준호 ( Park Joonho ),김기성 ( Kim Ki-sung ),임경재 ( Lim Kyung Jae ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

Soil erosion is a natural process and has been occurring in most areas in the watershed. However, accelerated soil erosion rates have been causing numerous environmental impacts in recent years. To reduce soil erosion and sediment inflow into the water bodies, site-specific soil erosion best management practices (BMPs) need to be established and implemented. The most commonly used soil erosion model is the Universal Soil Loss Equation (USLE), which have been used in many countries over 30 years. The Sediment Assessment Tool for Effective Erosion Control (SATEEC) ArcView GIS system has been developed and enhanced to estimate the soil erosion and sediment yield from the watershed using the USLE input data. In the last decade, the Soil and Water Assessment Tool (SWAT) model also has been widely used to estimate soil erosion and sediment yield at a watershed scale. The SATEEC system estimates the LS factor using the equation suggested by Moore and Burch, while the SWAT model estimates the LS factor based on the relationship between sub watershed average slope and slope length. Thus the SATEEC and SWAT estimated soil erosion values were compared in this study. The differences in LS factor estimation methods in the SATEEC and SWAT caused significant difference in estimated soil erosion. In this study, the difference was -51.9%(default threshold)~-54.5%(min. threshold) between SATEEC and non-patched SWAT, and -7.8%(default threshold)~+3.8%(min. threshold) between SATEEC and patched SWAT estimated soil erosion.

VFSMOD-W 모형을 이용한 SWAT 모형의 초생대 유사 저감 효율 모듈 개선

박윤식 ( Younshik Park ),김종건 ( Jonggun Kim ),장원석 ( Won-seok Jang ),유동선 ( Dongseon Yoo ),최중대 ( Joongdae Choi ),임경재 ( Kyoung Jae Lim ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

Environment problem has been arising in many countries. Especially, soil erosion has been deemed as one of the biggest issues because sediment causes muddy water and pollutants, such as agricultural chemicals, flow in the stream with this sediment. Many studies, regarding soil loss and non-point source pollution from watershed, has been performed while serious problem has been known. Soil loss occurred in most agricultural area by rainfall and runoff. It makes hydraulic structure unstable, causes environmental economical problems because muddy water destroys ecosystem and causes intake water deterioration. As revealing serious effects of muddy water by sediment, many researches have been doing with various methods. Hydraulic structures establishments such as soil erosion control dams and grit chamber are common. Vegetative filter strip is investigated in this study because vegetative filter strip is designed for reducing sediment from upland areas of the watershed, and it has many functions, not only sediment reduction but also runoff water quality improvement and wildlife habitat. With these positive functions of the vegetative filter strip, the study about vegetative filter strip has been increasing for reducing sediment because it is more effective than hydraulic structures from an environmental perspective. But the sediment trapping efficiency by vegetative filter strip, needs to be investigated and designed first. Therefore the model, VFSMOD-W, was used in this study as it can estimate sediment trapping efficiency of vegetative filter strip under various field, vegetation, weather condition. Sensitive factors to sediment trapping efficiency are studied with VFSMOD-W, and sediment trapping efficiency equation has been derived using two most sensitive factors. It is thought that the equation suggested in this study can be used in Soil and Water Assessment Tool (SWAT), to overcome the limit of SWAT filter strip module, which is based solely on filter strip width.

초생대의 유사 저감 효과 모의를 위한 Web 기반 VFSMOD 시스템의 구축

박윤식 ( Park Younshik ),김종건 ( Kim Jonggun ),임경재 ( Lim Kyung Jae ),현재연 ( Hyun Jae Yeon ),신용철 ( Shin Yonhchul ),안재훈 ( Ahn Jaehun ),김기성 ( Kim Ki-sung ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

More focus has been given to the study regarding the Non-Point Source Pollution, such as rainfall, sediment, pesticide, nutrient, and pathogens from urban, forest, and agricultural area, than Point Source Pollution. Muddy water problem has been raised at many areas in Korea. To solve the muddy water problem, many studies have been performed in not only Korea but also other countries using hydraulic structures such as sediment basin, erosion control dam, and others. Among these, the vegetative filter strip has been increasingly used because of its environment-friendly aspect. Vegetative filter strip is designed to reduce soil erosion and sediment discharges from the edge of the field due to rainfall-driven runoff. However, sometimes it is not possible to expect various design storm events in field experiment. Thus, the VFSMOD was selected in this study to develop prototype version of the Web GIS-based VFSMOD system (http://www.EnvSys.co.kr/~vfsmod) because sometimes it is difficult to prepare input dataset for the desktop version of the VFSMOD system. The Web GIS-based VFSMOD system uses the VFSMOD as core engines to simulate hydrology and sediment transport through vegetative filter strips. In the prototype Web GIS-based VFSMOD system, various database were used to help users parameterize the source and filter strip areas. In the prototype Web GIS-based VFSMOD system, Web GIS soil information system was developed and provided for ease selection of spatial location of interest and retrieval of corresponding soil properties for the Web GIS-based VFSMOD system. In this study, trapping efficiency was analyzed with the area which is located on edge of the stream. The trapping efficiency was various as the width of filter strip with rainfall event such as rainfall return period and rainfall duration. In this study area, filter strip which is at least 3.0m was needed for 80% of trapping efficiency to every rainfall condition, and filter strip which is at least 1.2m was needed for 50% of trapping efficiency to every rainfall condition.

LID 개념 적용으로 인한 유출 감소 특성 가능성 분석 및 바이모달 트램 전용노선에서의 적용성 검토

박준호(Junho Park),박영곤(Youngkon Park),윤희택(Heetaek Yoon),유용구(Yonggu Yoo),김종건(Jonggun Kim),박윤식(Younshik Park),임경재(Kyoung Jae Lim) 한국철도학회 2008 한국철도학회 학술발표대회논문집 Vol.- No.-

Changes in land uses at urbanizing areas are causing flooding, increase in NPS pollutants. Thus, Low Impact Development (LID) concept is now being employed in urban planning for sustainable development. Compared with the conventional BMPs, the LID is a new concept in urban planning to minimize the impacts of urbanization for site-specific LID IMPs. The objective of this study is to analyze the efficiency of LID adoption in study watershed in peak rate runoff and runoff volume reduction perspectives. The analysis revealed that the peak rate runoff and runoff volume decreased significantly with the LID adoption. This indicates that the Bimodal tram route with grass installed at the center of the road will contribute reduction in surface runoff and peak rate runoff, and also in NPS pollutant generation from the Bimodal tram route.

국내 경작지 특성을 고려한 SWAT 모형의 식생여과대 유사저감 효율 산정식 개선

한정호 ( Jeongho Han ),박윤식 ( Younshik Park ),금동혁 ( Donghyuk Kum ),정영훈 ( Younghun Jung ),정교철 ( Gyocheol Jung ),김기성 ( Kisung Kim ),임경재 ( Kyoungjae Lim ) 한국물환경학회 2015 한국물환경학회지 Vol.31 No.5

In this study, considering the factors that affects sediment trapping efficiency of Vegetative Filter Strips (VFS), the scenarios were designed to develop a regression equation to estimate sediment trapping efficiency of VFS for agricultural fields in South-Korea. For this, general conditions of agricultural fields in South-Korea were investigated. Then, based on these results, total 53,460 scenarios were set and simulated by Vegetative Filter Strip MODel (VFSMOD-w). Two variables were determined from the results of 53,460 scenarios. These two variables were applied to CurveExpert for development of a equation, which can estimate sediment trapping efficiency of VFS. The equation developed in this study can be used in SWAT model for estimation of sediment reduction efficiency of VFS to upland field in Korea. Moreover, it is expected that VFS will be effectively applied to agricultural fields in South-Korea.

SWAT ArcView GIS Extension Patch를 활용한 SWAT 예측유사량 분석

김종건 ( Kim Jonggun ),박윤식 ( Park Younshik ),강성근 ( Kang Sung-keun ),임경재 ( Lim Kyoung Jae ),신용철 ( Shin Yongchul ),김기성 ( Kim Ki-sung ),최중대 ( Choi Joongdae ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

The Soil and Water Assessment Tool (SWAT) model has been widely used in simulating hydrology, soil erosion/sediment, pesticide, and nutrient within the watershed. The SWAT model estimates the slope length of each Hydrologic Response Unit (HRU) within subwatershed with the average slope of subwatershed. However topographic information extraction module in the SWAT ArcView system cannot be applied for steep watershed. Thus, the slope length values were modified with the ArcView Avenue programming. In this study, the 1:5000 digital maps were used to generate 7 DEMs (10m, 15m, 20m, 30m, 50m, 70m, 100m) for the Imha-dam watershed. The slope, slope length, estimated streamflow and sediment using various DEMs were compared in this study. As shown in this study, the use of DEM cell size of 100m or above could results in approximately 760% difference without SWAT ArcView GIS Extension Patch in slope length and 10% difference with SWAT ArcView GIS Extension Patch in slope length in estimated sediment yield although the same input data were used in model runs. Therefore, it is suggested that researchers or modelers use the detailed topographic data for accurate modeling of watershed hydrology and water quality using SWAT ArcView GIS Extension Patch utilized in this study.

실측 경사장 및 경사도를 고려한 양구 해안면 유역의 유사량 평가

유동선 ( Dongseon Yoo ),박윤식 ( Younshik Park ),김종건 ( Jonggun Kim ),장원석 ( Wonseok Jang ),김기성 ( Ki-sung Kim ),임경재 ( Kyoung Jae Lim ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

In this study, area-weighted slope and slope length module, considering measured field slope and slope length of the agricultural fields within the subwatershed, was developed using the ArcView Avenue programming to reflect the field topography of the SWAT(Soil and Water Assessment Tool) HRU in simulating the hydrology and water quality. Flow and sediment yield estimated values of the SWAT were compared with and without applying area-weighted slope and slope length module, developed in this study. There was 103% increases in estimated sediment with area-weighted slope and slope length module for the study watershed. The soil erosion and sediment yield from only agricultural field in Hae-an watershed was also assessed. There are 111% increase in estimated soil erosion and 112% increase in estimated sediment by applying area-weighted slope and slope length module.

경사지에서의 정확한 토양유실 및 유사량 분석을 위한 SWAT ArcView GIS Extension Patch 개발

김종건 ( Kim Jonggun ),박윤식 ( Park Younshik ),장원석 ( Jang Wonseok ),유동선 ( Yoo Dongsun ),김기성 ( Kim Ki-sung ),임경재 ( Lim Kyoung Jae ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

The watershed scale SWAT model divides the watershed into smallersubwatersheds for rainfall-runoff and pollutant generation at the field level and routing though stream networks. The SWAT model first needs to be calibrated and validated for accurate estimation through adjustment of various input parameters. However, in some instances the SWAT simulated results are greatly affected by the watershed delineation and DEM cell size. In this study, the SWAT ArcView GIS Patch II was developed for steep sloping watershed and its performance was evaluated for various thresholdvalue and DEM cell size scenarios when delineating subwatersheds using SWAT. The SWAT ArcView GIS Patch II was developed using the ArcView GIS Avenue program and Spatial Analyst library. The SWAT ArcView GIS Patch II is better than the SWAT ArcView GIS Patch I by Lim et al. (2007) because it reflects the topographic factor in calculating the field slope length of the HRU in the SWAT model. The simulated sediment value for 321 watershed (threshold value of 200 ha) is greater than that for 43 subwatershed (threshold value of 25ha) by 201% without applying the SWAT ArcView GIS Patch II. However, when the SWAT ArcView GIS Patch II was applied, the difference decreases (12% difference) for the same scenario. The simulated sediment value for DEM cell size of 50m is greater than that for DEM cell size of 10m by 19.80% without the SWAT ArcView GIS Patch II. However, the difference becomes smaller (3.41% difference) between 50m and 10m DEM scenarios. As shown in this study, the SWAT ArcView GIS Patch II can reduce differences in simulated sediment values for various watershed delineation and DEM cell size scenarios. Without the SWAT ArcView GIS Patch II, variations in the SWAT simulated results using various watershed delineation and DEM cell size scenarios could be greater than those from input parameter calibration. The results obtained in this study show that the SWAT ArcView GIS Patch II needs to be used when simulating hydrology and water quality for steep sloping watersheds (especially if average slope ofthe subwatershed is greater than 25%) for accurate simulation of hydrology and water quality using the SWAT model.

Google Map과 WAMIS 자료를 이용한 직접유출/기저유출 분리 시스템의 개발

임경재 ( Lim Kyoung Jae ),박윤식 ( Park Younshik ),김종건 ( Kim Jonggun ),허성구 ( Heo Sung Gu ),신용철 ( Shin Yongchul ),유동선 ( Yoo Dong Sun ),김기성 ( Kim Ki-sung ),최중대 ( Choi Joongdae ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

The Geographic Information System has been widely used in every aspect of our lives. Many attempts have been made using freely available Google Map API, which provides various GIS and other functionalities with high-resolution satellite images all over the world. These high resolution data by the Google Map is very efficient in locating target area of interest compared with vector dataset. Therefore, the Google Map was used to develop Web GIS interface in locating the gaging station in Korea. The Web-based Hydrograph Analysis Tool (WHAT) was enhanced using the Google Map interface in this study. The Google Map interface was linked to the WAMIS web site for automatic retrieval of daily flow data for automatic baseflow separation Also, the Google Map WHAT interfaces were extended for 48 states in the US (http://www.EnvSys. co.kr/~what, http://cobweb.ecn.purdue.edu/~what/WHAT_GOOGLE). The biggest advantage of using the Google Map interface is that system developers do not need to install Web GIS system on the server, which is sometimes either expensive or heavy for the server. Also, numerous Google Map API can be integrated into the system with minor modifications, enabling very cost-effective Web GIS application. The easy-to-use Google Map interface WHAT system can be efficiently used in calibrating and validating hydrologic and water quality models. The Korea Department of Environment water quality data will be linked to the WHAT system for automatic analysis of water quality trends and pollutant loads characteristics.

겨울철 융설을 대비한 바이모달 트램 재해관리 시스템의 SWMM 모형 적용성 평가

김종진(Jonggun Kim),박영곤(Youngkon Park),윤희택(Heetaek Yoon),박윤식(Younshik Park),장원석(Wonseok Jang),유동선(Dongseon Yoo),임경재(Kyoung Jae Lim) 한국철도학회 2008 한국철도학회 학술발표대회논문집 Vol.- No.-

Increasing urban sprawl and climate changes have been causing unexpected high-intensity rainfall events. Thus there are needs to enhance conventional disaster management system for comprehensive actions to secure safety. Therefore long-term and comprehensive flood management plans need to be well established. Recently torrential snowfall are occurring frequently, causing have snow traffic jams on the road. To secure safety and on-time operation of the Bi-modal tram system, well-structured disaster management system capable of analyzing the urban flash flooding and snow pack melt/freezing due to unexpected rainfall event and snowfall are needed. To secure safety of the Bi-modal tram system due to torrential snowfall, the snow melt simulation capability was investigated. The snow accumulation and snow melt were measured to validate the SWMM snow melt component. It showed that there was a good agreement between measured snow melt data and the simulated ones. Therefore, the Bi-modal tram disaster management system will be able to predict snow melt reasonably well to secure safety of the Bi-modal tram system during the winter. The Bi-modal tram disaster management system can be used to identify top priority area for snow removal within the tram route in case of torrential snowfall to secure on-time operation of the tram. Also it can be used for detour route in the tram networks based on the disaster management system predicted data.