• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.48-48
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• 2012

유역 내 고농도의 탁수문제는 수자원의 효용 가치 하락, 댐 기능의 저하 및 관광 자원으로써의 가치 하락으로 인한 경제적 손실을 발생시킨다. 또한 자원으로서의 토양손실을 야기시켜 토양 재조성을 위한 시간적, 비용적 문제를 발생시킨다. 하천의 탁수저감, 자원으로써의 토양 보전 관리를 위해서는 토양유실 저감 대책을 세우는 것이 필요하며, 이를 위해서는 정확한 토양유실량 및 유사량을 평가하여야 한다. 토양유실량 및 유사량을 평가하기 위해 Sediment Assessment Tool for Effective Erosion Control (SATEEC)이 널리 사용되어 오고 있으며, SATEEC System은 다양한 모듈 보완을 통하여 현재 SATEEC System ver. 2.2까지 개발되었다. SATEEC System ver. 2.2는 시공간변화를 고려한 일단위 R factor산정이 가능하며, 이 R factor산정 모듈은 단일강우를 고려할 수 있는 Williams, Foster, Cooley, CREAMS의 R factor산정 공식을 기반으로 하고 있다. 그리고 SATEEC System ver. 2.2에서는 같은 속성의 셀에 대해서는 함께 연산이 이루어지기 때문에, 유역의 크기나 셀크기에 상관없이 최대 연산시간은 비슷하다. 본 연구에서는 이렇게 개발된 SATEEC System ver. 2.2룰 이용하여 낙동강 수계에 위치한 임하댐유역의 유사량을 평가하였으며, 유사량 평가를 위한 유달률 산정을 위하여 유전자 알고니즘 기반의 SATEEC SDR모듈을 사용하였다. 유사량 평가 결과 보정기간동안 $R^2$ = 0.591, NSE = 0.573, 검정기간 동안 $R^2$ = 0.927, NSE = 0.911로 높은 적용성을 보이는 것으로 나타났다. 본 연구에서 사용된 SATEEC System ver. 2.2는 표토 보전 및 관리를 위한 예비 단계 평가 툴로 활용될 수 있을 것이라 판단된다.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.2
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• pp.19-26
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• 2011

SATEEC ArcView GIS system was developed using the Universal Soil Loss Equation (USLE) and sediment delivery ratio (SDR) modules. In addition, time-variant R and C modules and $R_5$ module were developed and integrated into the SATEEC system in recent years. The SATEEC ArcView GIS 2.1 system is a simple-to-use system which can estimate soil erosion and sediment yield spatially and temporarily using only USLE input data, DEM, and daily rainfall dataset. In this study, the SATEEC 2.1 system was used to evaluate the effects of USLE LS input data considering slope length segmentation on soil erosion and sediment yield estimation. Use of USLE LS with slope length segmentation due to roads in the watershed, soil erosion estimation decreased by 24.70 %. However, the estimated sediment yield using SATEEC GA-SDR matched measured sediment values in both scenarios (EI values of 0.650 and EI 0.651 w/o and w/flow segmentation). This is because the SATEEC GA-SDR module estimates lower SDR in case of greater soil erosion estimation (without flow length segmentation) and greater SDR in case of lower soil erosion estimation (with flow length segmentation). This indicates that the SATEEC soil erosion need to be estimated with care for accurate estimation of SDR at a watershed scale and for accurate evaluation of BMPs in the watershed.

• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.113-124
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• 2009

Severe sediment-laden problem has been the hot issue in Korea. It was assumed that agricultural activities and landslides were the primary causes of these problems in watersheds. The USLE-based systems have been widely used in soil erosion studies. However the GIS-based USLE modeling system has limitation in USLE L factors. In this study, the SATEEC L module was developed to reflect the slope length segmentations in the fields. The SATEEC L module was applied to the study watershed to analyze the effects of using the SATEEC L module on estimated sediment. As shown in the comparisons between SATEEC estimated sediment with SWAT values, the SATEEC GA-SDR module derives the SDR with reasonably acceptable accuracies. However, it is worthy to note that the soil erosion using the SATEEC L module for the study watershed was lower than that without using the SATEEC L module by 25%, although the SATEEC estimated sediment values with and without using L module match the SWAT sediment values with similar accuracies. This is because the SATEEC GA-SDR module estimates lower SDR in case of greater soil erosion estimation without the L module and greater SDR in case of lower soil erosion estimation with the L module. This indicates that the SATEEC input parameters, especially L factor, need to be prepared with care for accurate estimation of SDR at a watershed scale and for accurate evaluation of BMPs in the watershed.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.497-506
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• 2010

Severe muddy water problem has been the hot issue in Korea. Because of increased nonpoint source pollutions at Kangwon province, best soil erosion management system is required to reduce inflow of nonpoint source pollutions into the waterbodies. The USLE-based SATEEC system have been developed and enhanced for soil erosion and sediment yield estimation. However, the SATEEC cannot estimate soil depositions depending on topography in the watershed, while the USPED estimates soil erosion and deposition using sediment transport capacity of the surface runoff. In this study, the SATEEC and USPED were used to determine soil erosion hot spot subbasins. For this, 54 subbasins were delineated. In general, soil erosion hot spot subbasins were identified similarly with SATEEC and USPED. However, depending on erosion and deposition patterns in each subbasin. USPED estimated soil erosion hot spot subbasins didn't match those estimated with SATEEC. For some subbasins, much deposition was expected than erosion. This indicates that SATEEC estimated soil erosion values may be overestimated for these subbasins. Thus, care should be taken when understanding soil erosion status in the watershed based on USLE-based SATEEC results. In addition, the USPED results could be used to identify the site-specific soil erosion best management practices. If the USPED and USLE-based SATEEC are combined, it would help determining soil erosion hot spot subwatersheds in economic and environmental perspectives.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.335-335
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• 2011

토양유실은 농업환경지표를 비롯한 국제 규범에서 농업에 의한 환경오염의 핵심문제로 제기되고 있다. 이러한 토양유실의 문제점을 해결하기 위해 USLE를 기반으로 한 SATEEC모형을 사용하여 토양유실량 및 유사량을 산정하였다. SATEEC모형은 USLE입력자료와 DEM을 이용하여 산정된 토양유실량 과 GA-SDR모듈을 통해 산정된 유달률(Sediment Delivery Ratio, SDR)을 통하여 최종유출구에서의 유사량을 산정한다. 많은 연구자들은 최종유출구에서의 유사량을 실측유사량과 비교하여 비슷하게 모의되면 유역의 특성을 잘 반영한다고 판단하므로 SATEEC모형의 단점인 토양유실량이 과하게 산정되는 문제점을 중요하게 생각하지 않는다. 하지만 SATEEC 모형의 결과값인 유사량의 신뢰도를 향상시키기 위해서는 토양유실량 검증을 통한 정확한 입력자료 구축이 필요하다. 따라서 본 연구에서는 여러개의 토양유실량 시나리오를 만들어 이에 따른 SATEEC 모형의 유사량을 비교/평가하고, 이를 이용하여 토양유실량의 검증이 필요함을 제시하고자 한다. 본 연구에서 사용한 토양유실량 시나리오는 총 4개로써, 시나리오 1은 SATEEC모형을 이용하여 산정된 토양유실량이며, 시나리오2~4는 ArcGIS를 사용하여 기존의 토양유실량 값에 ${\pm}0.25$의 범위를 주어 새롭게 산정된 토양유실량으로 SATEEC모형을 이용한 유사량 산정시 입력자료로 활용하였다. 그 결과 SATEEC모형을 이용하여 산정된 토양유실량은 시나리오별로 차이를 보였다. 또한 SATEEC GA-SDR모듈을 통해 예측된 토양유실량 값과 실측유사량을 이용하여 유달률을 산정하였으며 유달률도 토양유실량 시나리오별로 차이를 보였다. 따라서 SATEEC모형을 이용하여 최종유출구에서의 유사량 산정 결과 토양유실량의 차이에도 불구하고 유사량은 거의 비슷한 값을 나타내고 있으며, 최종유출구에서의 모의된 예측 유사량이 실측유사량과 비교 시 R2=0.688, EI=0.643 정도로 실측유사량과 비슷한 경향을 나타냈다. 따라서 SATEEC모형을 이용하여 유사량 산정시 먼저 문헌을 통한 토양유실량 검증이 필요하리라 판단되며, 문헌을 통해 토양유실량 검증 후 정확한 입력자료를 구축하여 유역에서의 유사량 저감을 위한 최적관리 기법 분석에 사용할 수 있도록 프로세서를 구축해야 할 것이라 판단된다.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.983-990
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• 2011

Universal Soil Loss Equation (USLE) has been used to estimate potential long-term soil erosion in the fields. However, the USLE does not estimate sediment yield due to lack of module considering sediment delivery ratio (SDR) for watershed application. For that reason, the Sediment Assessment Tool for Effective Erosion Control (SATEEC) system was developed and applied to compute the sediment yield at watershed scale. However, the R factor of current SATEEC Ver. 2.1 was estimated based on 5-day antecedent rainfall, it is not related with fundamental concept of R factor. To compute R factor accurately, the energy of rainfall strikes should be considered. In this study, the R module in the SATEEC system was enhanced using formulas of Williams, Foster, Cooley, CREAMS which could consider the energy of rainfall strikes. The enhanced SATEEC system ver. 2.2 was applied to the Imha watershed and monthly sediment yield was estimated. As a result of this study, the $R^2$ and NSE values are 0.591 and 0.573 for calibration period, and 0.927 and 0.911 for validation period, respectively. The results demonstrate the enhanced SATEEC System estimates the sediment yield suitably, and it could be used to establish the detailed environmental policy standard using USLE input dataset at watershed scale.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1295-1299
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• 2008

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)$\sim$-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.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.1
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• pp.3-12
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• 2008

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.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.841-849
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• 2010

Soil erosion is an natural phenomenon. However accelerated soil erosion has caused many environmental problems. To reduce soil loss from a watershed, many management practices have been proposed worldwide. To develop proper and efficient soil erosion best management practices, soil erosion rates should be estimated spatially and temporarily. The Universal Soil Loss Equation (USLE) and USLE-based soil erosion and sediment modelling systems have been developed and tested in many countries. The Sediment Assessment Tool for Effective Erosion Control (SATEEC) system has been developed and enhanced to provide ease-of-use interface to the USLE users. However many researchers and decision makers have requested to enhance the SATEEC system for simulation of soil erosion and sediment reflecting effects of single storm event. Thus, the SATEEC R factors were estimated based on 5 day antecedent rainfall data. The SATEEC 2.1 daily R factor was applied to the study watershed and it was found that the R2 and EI values (0.776 and 0.776 for calibration and 0.927 and 0.911 for validation) with the daily R were greater than those (0.721 and 0.720 for calibration and 0.906 and 0.881 for validation) with monthly R, which was available in the SATEEC 2.0 system. As shown in this study, the SATEEC with daily R can be used to estimate soil erosion and sediment yield at a watershed scale with higher accuracy. Thus the SATEEC with daily R can be efficiently used to develop site-specific soil erosion best management practices based on spatial and temporal analysis of soil erosion and sediment yield at a daily-time step, which was not possible with USLE-based soil erosion modeling system.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.637-647
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• 2010

The Universal Soil Loss Equation (USLE)-based modeling systems have been widely used to simulate soil erosion studies. However the GIS-based USLE modeling systems have limitation in gully erosion evaluation which is one of the most important factor in soil erosion estimation. In this study, the integrated soil erosion evaluation system using with Sediment Assessment Tool for Effective Erosion Control (SATEEC) system, nLS and Unit Stream Power-based Erosion/Deposition (USPED) model was developed to simulate gully erosion. Gully head location using nLS model, USPED for gully erosion, and the SATEEC estimated sheet and rill erosion were evaluated and combined together with the integrated soil erosion evaluation system. This system was applied to the Haean-myeon watershed, annual average sediment-yield considering sheet, rill and gully erosion was simulated as 101,933 ton/year at the study watershed. if the integrated soil erosion evaluation system is calibrated and validated with the measured data, this system could be efficiently used in developing site-specific soil erosion best management system to reduce soil erosion and muddy water inflow into the receiving waterbody.