비점오염원 관리지역(소양호) 목표수질 달성도 평가

최재완 ( Jae Wan Choi ),강민지 ( Min Ji Kang ),류지철 ( Ji Chul Ryu ),김동일 ( Dong Il Kim ),임경재 ( Kyung Jae Lim ),신동석 ( Dong Seok Shin ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.5

bstractThe Ministry of Environment (MOE) has made more effort in managing point source pollution rather than in nonpoint source pollution in order to improve water quality of the four major rivers. However, it would be difficult to meet water quality targets solely by managing the point source pollution. As a result of the comprehensive measures established in 2004 under the leadership of the Prime Minister’s Office, a variety of policies such as the designation of control areas to manage nonpoint source pollution are now in place. Various action plans to manage nonpoint source pollution have been implemented in the Soyang-dam watershed as one of the control areas designed in 2007. However, there are no tools to comprehensively assess the effectiveness of the action plans. Therefore, this study would assess the action plans (especially, BMPs) designed to manage Soyang-dam watershed with the WinHSPF and the CE-QUAL-W2. To this end, we simulated the rainfall-runoff and the water quality (SS) of the watershed and the reservoir after conducting model calibration and the model validation. As the results of the calibration for the WinHSPF, the determination coefficient (R2) for the flow (Q, m3/s) was 0.87 and the R2 for the SS was 0.78. As the results of the validation, the former was 0.78 and the latter was 0.67. The results seem to be acceptable. Similarly, the calibration results of the CE-QUAL-W2 showed that the RMSE for the water level was 1.08 and the RMSE for the SS was 1.11. The validation results(RMSE) of the water level was 1.86 and the SS was 1.86. Based on the daily simulation results, the water quality target (turbidity 50 NTU) was not exceeded for 2009∼2011, as results of maximum turbidity in ``09, ``10, and ``11 were 3.1, 2.5, 5.6 NTU, respectively. The maximum turbidity in the years with the maximum, the minimum, and the average of yearly precipitation (1982∼2011) were 15.5, 7.8, and 9.0, respectively, and therefore the water quality target was satisfied. It was discharged high turbidity at Inbuk, Gaa, Naerin, Gwidun, Woogak, Jeongja watershed resulting of the maximum turbidity by sub-basins in 3years(2009∼2011). The results indicated that the water quality target for the nonpoint source pollution management should be changed and management area should be adjusted and reduced.

보청A유역 유량 및 영양물질 자동보정을 위한 HSPF-PEST 연계적용

전지홍,최동혁,임경재,김태동,Jeon, Ji-Hong,Choi, Dong-Hyuk,Lim, Kyung-Jae,Kim, Tae-Dong 한국농공학회 2010 한국농공학회논문집 Vol.52 No.5

Hydrologic Simulation Program-Fortran (HSPF) coupled with PEST which is optimization program was calibrated and validated at Bochung watershed by using monitoring data of water quantities and nutrient loading. Although the calibrated data were limited, model parameters of each land use type were optimized and coefficient of determinations were ranged from 0.94 to 0.99 for runoff, from 0.89 to 1.00 for TN loading, and from 0.92 to 1.00 for TP loading. The optimized hydrological parameters indicated that the forested land could retain rainfall within soil layer with high soil layer depth and infiltration rate compared with other land use type. Hydrological characteristics of paddy rice field are low infiltration rate and coefficient of roughness. The calibrated parameters related to nutrient loading indicated generation of nutrient pollution from agricultural area including upland and paddy rice field higher than other land use type resulting from fertilizer application. Overall PEST program is useful tool to calibrate HSPF automatically without consuming time and efforts.

북한강 중류 산간농업 소하천에서의 오염부하특성분석

신용철,최중대,임경재,심혁호,류창원,양재의,유경열,Shin, Yong-Chul,Choi, Joong-Dae,Lim, Kyoung-Jae,Shim, Hyeok-Ho,Lyou, Chang-Won,Yang, Jae E.,Yoo, Kyung-Yoal 한국농공학회 2005 한국농공학회논문집 Vol.47 No.6

Natural environment of the Wolgokri stream watershed, located in Chuncheon, Gangwon province, Korea, has been well preserved as a traditional agricultural watershed. To analyze characteristics of NPS pollution generated from an mountainous agricultural watershed, the flow and water qualities of the study watershed were monitored and were analyzed to estimate pollution loads. Annual runoff volume ratio was $70.4\%$. Concentrations of T-N, T-p, COD, and TOC were higher when monthly rainfall was between $0\~30mm$ than those when monthly rainfall was between $30\~70mm$. However, the concentrations varied considerably when monthly rainfall was higher than 100mm. The flow weighted mean concentrations(mg/L) of BOD, COD, TOC, $NO_3-N$, T-N, T-P and SS were 1.96, 2.72, 3.32, 1.41, 4.70, 0.187 and 13.36, respectively. The BOD, SS, T-N and T-P loads of July, 2004 were $48\%,\;17\%,\;51\%\;and\;32\%$ of annual load, respectively. The BOD, COD, TOC, $NO_3-N$, T-N, T-p, and SS loads (kg/ha) from Mar. 2004 to Apr. 2005 were 19.09, 26.55, 32.39, 13.85, 45.92, 1.887 and 130.18, respectively. The highest concentrations of BOD, NO3-N, T-N, T-p, SS, COD and TOC were found before the flow reached the peak runoff, possibly due to the first flushing effect. Generally, pollution loads of the Wolgokri watershed were not that significant. Phosphorus load, however, was higher enough to cause eutrophication in the receiving water body It was recommended that best management practices need to be implemented to reduce phosphorus sources.

소유역 유달율 추정공식 개발 -보청A유역을 중심으로-

전지홍,최동혁,임경재,김태동,Jeon, Ji-Hong,Choi, Dong-Hyuk,Lim, Kyung-Jae,Kim, Tae-Dong 한국농공학회 2010 한국농공학회논문집 Vol.52 No.5

The characteristics of delivered nutrient loads were analyzed and the regression equations to estimate delivery ratios of nutrients (TN and TP) were developed using HSPF simulation results at six subwatersheds within the Bochung A unit watershed during 1998-2007. TN delivery ratio was higher than TP delivery ratio because significant amounts of TP was considered to be attached at soil as ${PO_4}^-$ during delivery process from discharged point of nutrient source to main stream. As a results of correlation analysis, factors related to geomorphic characteristics had not statistical correlation with TN and TP delivery ratios. TN loading rate from living and specific stream flow had statistical negative and positive correlation, respectively, with TN delivery ratio. TP loading rates from all sources and from land cover and specific stream flow had statistical negative, negative and positive correlation, respectively. The specific stream flow represents the most strong correlation with nutrient delivery ratios. The regression equations to estimate delivery ratios for TN and TP were developed by including statistical correlated factors and showed high efficiency of 0.98 and 0.95 of coefficient of determination for TN and TP, respectively.

원격탐사자료를 이용한 시,공간적으로 분포되어 있는 토양수분산정 및 가뭄평가: (II) 가뭄

신용철 ( Yongchul Shin ),최경숙 ( Kyung Sook Choi ),정영훈 ( Younghun Jung ),양재의 ( Jae E. Yang ),임경재 ( Kyoung Jae Lim ) 한국물환경학회 2016 한국물환경학회지 Vol.32 No.1

Based on the soil moisture data assimilation suggested in the first paper (I), we estimated root zone soil moisture and evaluated drought severity using remotely sensed (RS) data. We tested the impacts of various spatial resolutions on soil moisture variations, and the model outputs showed that resolutions of more than 2-3 km resulted in over-/under-estimation of soil moisture values. Thus, we derived the 2 km resolution-scaled soil moisture dynamics and assessed the drought severity at the study sites (Chungmi-cheon sites 1 and 2) based on the estimated soil/root parameters and weather forcings. The drought indices at the sites were affected mainly by precipitation during the spring season, while both the precipitation and land surface characteristics influence the spatial distribution of drought during the rainy season. Also, the drought severity showed a periodic cycle, but additional research on drought cycles should be conducted using long-term historical data. Our proposed approach enabled estimation of daily root zone soil moisture dynamics and evaluation of drought severity at various spatial scales using MODIS data. Thus, this approach will facilitate efficient management of water resources.

GEOWEPP 모형을 이용한 고랭지 경사지밭 소유역의 토양유실 저감방안

문종필,김태철,이성현,권진경,이수장,임경재,Moon, Jong-Pil,Kim, Tai-Cheol,Lee, Sung-Hyoun,Kwon, Jin-Kyung,Lee, Su-Jang,Lim, Kyoung-Jae 한국농공학회 2010 한국농공학회논문집 Vol.52 No.6

This study was performed to suggest a soil loss reduction skill through estimating soil erosion from a small watershed including each type of sloping agriland by using GEOWEPP model. Experimental watershed at Gangwon province was selected for very typical sloping fields of highland agriculture in Alpine area. Runoff discharge and sediment load, hourly rainfall amount occurred during storm event were gauged, and weather data were obtained from Daegwallyeong meteorological station. The results of GEOWEPP model estimation showed that relative error values for total runoff discharge and sediment load were 3 %, -14.5 % respectively. Based on the result, soil erosion and waterway path map for each hillslope were made to select target hillslope. Several hillslopes of severe soil erosion were analyezed and then the optimal vegetative filter strip construction width and waterway path to plant grass were decided by using GEOWEPP Model.

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.

토지피복기반 점근 CN 회귀식 개발

류지철 ( Jichul Ryu ),박배경 ( Bae Kyung Park ),김용석 ( Yong Seok Kim ),( Beranrd A Engel ),임경재 ( Kyoung Jae Lim ) 한국물환경학회(구 한국수질보전학회) 2016 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2016 No.-

SWAT과 SATEEC 모형을 이용한 토양유실량 비교

박윤식,김종건,허성구,김남원,안재훈,박준호,김기성,임경재,Park, Youn-Shik,Kim, Jong-Gun,Heo, Sung-Gu,Kim, Nam-Won,Ahn, Jae-Hun,Park, Joon-Ho,Kim, Ki-Sung,Lim, Kyung-Jae 한국농공학회 2008 한국농공학회논문집 Vol.50 No.1

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 trom 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)${\sim}-54.5%$(min. threshold) between SATEEC and non-patched SWAT, and -7.8%(default threshold)${\sim}+3.8%$(min. threshold) between SATEEC and patched SWAT estimated soil erosion.

예초 및 관수에 따른 골프장 유출특성 평가

최재완 ( Jaewan Choi ),이성준 ( Sung Jun Lee ),천세억 ( Se Uk Cheon ),임경재 ( Kyung Jae Lim ) 한국농공학회 2011 한국농공학회 학술대회초록집 Vol.2011 No.-

골프산업은 매년 증가추세에 있으며, 이에 따라 국내 골프장 수도 늘어나고 있다. 골프장은 비료사용으로 인한 유기 화합물의 유출로 수생태계에 악영향을 미칠 수 있는데, 이는 주로 강우유출수로부터 발생된다. 환경적 측면 뿐만이 아니라, 골프장은 저류지를 이용하여 강우유출수를 한 곳으로 모아 잔디의 관수로 사용되므로 골프장 운영 측면에서도 강우유출 특성을 파악하는 것이 중요하다. 따라서 본 연구에서는 WEPP 모형을 이용하여 골프장 잔디성장을 고려한 강우유출수 특성을 평가하였으며, 예초 및 관수에 따른 잔디성장과 강우유출수 예측을 통하여 골프장에서 발생하는 유출특성 및 골프장 운영에 대한 기초자료를 제시하고자 한다. WEPP 모형의 유출 정확성 평가 결과 보정시 %diff.는 1.15%, NSE는 0.92, R2는 0.93으로 산정되었고, 검증시 %diff.는 18.12%, NSE는 0.82, R2는 0.88로 산정되었다. 따라서 WEPP 모형이 골프장에서 발생하는 강우유출수를 정확히 예측할 수 있는 것으로 판단되었다. 예초 유ㆍ무에 따른 유출량 예측결과 총 2774.5m3이 차이나는 것으로 나타났으며, 이는 예초를 한 경우보다 예초를 안한 경우에 27% 유출이 감소하는 것이다. WEPP 모형을 이용하여 관수에 따른 골프장 잔디의 생육과 유출특성을 비교한 결과 관수를 하는 경우 잔디의 생육을 촉진시키는 것으로 나타났다. 관수 유ㆍ무에 따른 유출량은 총 11.8% 차이가 나는 것으로 나타났으며, 가장 차이가 많이 나는 경우 27.4% 정도로 나타났다. 강우유출수는 골프장에서 사용하는 물의 상당부분을 차지하고 있으므로 관수량을 적절히 조절하여 골프장을 효율적으로 운영할 수 있을 것으로 판단된다.