• 제목/요약/키워드: universal soil loss equation

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필지 단위 주경사장 산정 및 적용을 통한 범용토양유실공식 지형인자 산정 개선 연구 (A Study to Determine the Slope Length and Steepness Factor of Universal Soil Loss Equation with Determining and Adapting Major Slope Length at Field Scale)

  • 박윤식;박종윤;장원석;김종건
    • 한국농공학회논문집
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    • 제61권6호
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    • pp.55-65
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    • 2019
  • Universal Soil Loss Equation (USLE) is to estimate potential soil loss and has benefit in use with its simplicity. The equation is composed of five factors, one of the factors is the slope length and steepness factor (LS factor) that is for topographic property of fields to estimate potential soil loss. Since the USLE was developed, many equations to compute LS was suggested with field measurement. Nowadays the factor is often computed in GIS software with digital elevation model, however it was reported that the factor is very sensitive to the resolution of digital elevation model. In addition, the digital elevation model of high resolution less than 3 meter is required in small field application, however these inputs are not associate with the empirical models' backgrounds since the empirical models were derived in 22.1 meter field measurements. In the study, four equation to compute LS factor and two approaches to determine slope length and steepness were examined, and correction factor was suggested to provide reasonable precision in LS estimations. The correction factor is computed with field area and cell size of digital elevation model, thus the correction factor can be adapted in any USLE-based models using LS factor at field level.

산림유역의 토양유실량(土壤流失量) 예측을 위한 지리정보(地理情報)시스템의 범용토양유실식(汎用土壤流失式)(USLE)에의 적용 (Application of GIS to the Universal Soil Loss Equation for Quantifying Rainfall Erosion in Forest Watersheds)

  • 이규성
    • 한국산림과학회지
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    • 제83권3호
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    • pp.322-330
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    • 1994
  • 토양침식에 영향을 미치는 강우, 토양, 지형, 식생 등을 종합적으로 고려하여 단위면적당 토양유실량(土壤流失量)을 예측하는 범용토양유실식(汎用土壤流失式)(Universal Soil Loss Equation)을 지리정보(地理情報)시스템(GIS)에 접목시켰다. 경기도 광릉 임업연구원 시험림을 연구지역으로 선정하여 이곳에서 지난 12년 동안 측정된 시간별 강우자료를 이용하여 강우인자(强雨因子)(R) 값을 산출하였고, 토양도, 지형도, 위성자료 등을 이용하여 USLE 계산에 필요한 다른 인자들의 값을 $25{\times}25m^2$의 격자마다 입력하여 디지털공간정보 데이터베이스를 구축하였다. 각 격자단위로 USLE에 의하여 토양유실량이 계산된 후 그 결과를 종합하여 토양유실의 정도를 공간적으로 살펴볼 수 있는 디지털지도가 산출되었다. GIS에 의한 USLE의 적용은 일정한 테두리 안의 산림유역(山林流域)에서 발생되는 강우에 의한 토양유실량을 추정할 수 있을 뿐만아니라, 주변지역과 비교하여 토양유실의 위험이 높은 특정지점을 공간적으로 파악할 수 있다는 장점이 있다. 이러한 접근 방법은 임지전용(林地轉用), 임도(林道)개설, 벌채, 산불 및 병충해에 의한 임지의 변화가 토양침식에 미치는 영향을 효과적으로 분석할 수 있는 도구로 사용될 수 있을 것이다.

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한국형 토양유실공식의 GIS 기반 모형에 의한 금강 유역에 대한 토양유실 우심지역 선정에 관한 연구 (A Study to Define Area of Concern for Potential Soil Loss in Geumgang Watershed by KORSLE-based GIS model)

  • 김종건;양재의;임경재;김성철;이기하;황상일;유나영;박윤식
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제22권6호
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    • pp.29-36
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    • 2017
  • Universal soil loss equation (USLE) has been frequently employed to estimate potential soil loss in land since it was developed based on the statewide data measured and collected in the United States. The equation is an empirical model mainly used for U.S. soil, thus it has been recently modified to reflect Korean soil conditions and named as Korean Soil Loss Equation (KORSLE). The modified equation was implemented in ArcGIS software, and used for estimation of potential soil loss from 2003 to 2016 in the thirty-eight Water Protection Districts. Five out of the thirty-eight districts were identified as the area of potential soil erosion most severly. In those five districts, potential soil erosion were estimated to be more than 50 Mg/ha/year that requires site investigation under supervision of the Korean Ministry of Environment. Distinctive site characteristics were found in the potential soil loss estimation such that the districts of low potential soil loss had low five factors in the aggregate. However, if one of more factors are dominantly large, the potential soil loss significantly increased. This study provides a useful tool to identify the potential areas for soil erosion and the important factors that play an important role in the estimation process.

Region-Scaled Soil Erosion Assessment using USLE and WEPP in Korea

  • Kim, Min-Kyeong;Jung, Kang-Ho;Yun, Sun-Gang;Kim, Chul-Soo
    • 한국환경농학회지
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    • 제27권4호
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    • pp.314-320
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    • 2008
  • During the summer season, more than half of the annual precipitation in Korea occurs during the summer season due to the geographical location in the Asian monsoon belt. So, this causes severe soil erosion from croplands, which is directly linked to the deterioration of crop/land productivity and surface water quality. Therefore, much attention has been given to develop accurate estimation tools of soil erosion. The aim of this study is to assess the performance of using the empirical Universal Soil Loss Equation (USLE) and the physical-based model of the Water Erosion Prediction Project (WEPP) to quantify eroded amount of soil from agricultural fields. Input data files, including climate, soil, slope, and cropping management, were modified to fit into Korean conditions. Chuncheon (forest) and Jeonju (level-plain) were selected as two Korean cities with different topographic characteristics for model analysis. The results of this current study indicated that better soil erosion prediction can be achieved using the WEPP model since it has better power to illustrate a higher degree of spatial variability than USLE in topography, precipitation, soils, and crop management practices. These present findings are expected to contribute to the development of the environmental assessment program as well as the conservation of the agricultural environment in Korea.

한국형 토양유실공식에 의한 토양유실량 현장예측 (Application of KORSLE to Estimate Soil Erosion at Field Scale)

  • 송재민;양재의;임경재;박윤식
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제24권5호
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    • pp.31-41
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    • 2019
  • In 2013, the Ministry of Environment in South Korea promulgated a new regulatory bulletin that contained revised enforcement ordinance on soil management protocols. The bulletin recommends the use of Universal Soil Loss Equation (USLE) for the soil erosion estimation, but USLE has limited applicability in prediction of soil erosion because it does not allow direct estimation of actual mass of soil erosion. Therefore, there is a great need of revising the protocol to allow direct comparison between the measured and estimated values of soil erosion. The Korean Soil Loss Equation (KORSLE) was developed recently and used to estimate soil loss in two fields as an alternative to existing USLE model. KORSLE was applied to estimate monthly rainfall erosivity indices as well as temporal variation in potential soil loss. The estimated potential soil loss by KORSLE was adjusted with correction factor for direct comparison with measured soil erosion. The result was reasonable since Nash-Stucliff efficiency were 0.8020 in calibration and 0.5089 in validation. The results suggest that KORSLE is an appropriate model as an alternative to USLE to predict soil erosion at field scale.

RUSLE 모형으로 토사유실에 따른 사방댐 적정성 분석 (Analysis of the Adequacy Check Dam according to Soil Loss using RUSLE)

  • 최현
    • 한국측량학회지
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    • 제34권5호
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    • pp.515-524
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    • 2016
  • 산사태와 같은 피해는 집중 호우 등의 자연현상에 원인이 있다. 적절한 대응책으로는 사방댐 설치와 계류보전 등의 방식을 사용한다. 사방댐은 산비탈 붕괴지의 골이나 이에 접속된 계류의 최상류부에 설치하는 소규모의 댐을 말한다. 본 연구에서는 산사태가 난 후에 추가피해를 방지하기 위한 사방댐이 설치된 지역의 적정성을 분석하였다. 사방댐 최적지 분석을 위한 기존에 설치된 사방댐을 중심으로 접근성과 규모 등을 고려하여 GIS로 토사유실량을 검토하였다. RUSLE 모형으로 연구대상유역의 토사유실량을 검토한 결과 유역 I에서는 약 2%정도의 토양유실 감소효과가 있었고, 유역 II에서는 1% 미만의 토양유실 감소가 있는 것으로 나타났으며, 유역 III에서는 5% 대의 토사유실감소효과가 있는 것으로 나타났다.

미래기후변화를 반영한 금강 수변 구역에서의 표토 유실량 예측 (The Estimation of Soil Loss in the Buffer Zone of Guem River using a Simulation of Future Climate Change)

  • 이달희;정성래
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제19권6호
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    • pp.30-36
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    • 2014
  • The objective of this study is to estimate soil loss in the buffer zone of Guem river with future climate change simulation. Revised Universal Soil Loss Equation (RUSLE) model was used for the estimation of soil loss at the buffer zone of Guem river. As results of simulations, the area of the maximum soil loss potential was estimated as the Cheongsung-myeon Okchun-gun Chungcheongbuk-do. The soil losses were estimated to be 106.67 and 103.00 ton/ha/yr for the 2020 segi (2015-2025) and 2040 segi (2035-2045) in the Cheongsung-myeon area, respectively. Also, the estimated average values of soil losses in the Cheongsung-myeon with future climate change was 110.78 ton/ha/yr.

최근 강수 자료를 이용한 범용토양유실공식의 강우침식능인자 정의에 관한 연구 (A Study to Determine the Rainfall Erosivity Factor of Universal Soil Loss Equation using Recent Rainfall Data)

  • 김종건;장진욱;성각규;차상선;박윤식
    • 한국농공학회논문집
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    • 제60권6호
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    • pp.13-20
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    • 2018
  • Universal Soil Loss Equation (USLE) has been widely used to estimate potential soil loss because USLE is a simple and reliable method. The rainfall erosivity factor (R factor) explains rainfall characteristics. R factors, cited in the Bulletin on the Survey of the Erosion of Topsoil of the Ministry of Environment in the Republic of Korea, are too outdated to represent current rainfall patterns in the Republic of Korea. Rainfall datasets at one minute intervals from 2013 to 2017 were collected from fifty rainfall gauge stations to update R factors considering current rainfall condition. The updated R factors in this study were compared to the previous R factors which were calculated using the data from 1973 to 1996. The coefficient of determination between the updated and the previous R factors shows 0.374, which means the correlation is not significant. Therefore, it was concluded that the previous R factors might not explain current rainfall conditions. The other remarkable result was that regression equations using annual rainfall data might be inappropriate to estimate reasonable R factors because the correlation between annual rainfall and the R factors was generally unsatisfy.

토양유식공식의 강우침식도 분포에 관한 연구 (A Study of Distribution of Rainfall Erosivity in USLE/RUSLE for Estimation of Soil Loss)

  • 박정환;우효섭;편종근;김광일
    • 한국수자원학회논문집
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    • 제33권5호
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    • pp.603-610
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    • 2000
  • 토양침식에 영향을 미치는 기후 인자로는 강우, 기온, 바람, 습도 및 태양열 복사 등이 있다. 이들 인자 중 강우는 토양침식에 직접적인 영항을 미친다. 강우의 운동에너지는 토립자의 이탈을 유발하며 강우로 인해 발생하는 흐름은 이탈 토립자를 연행시킨다. 토양침식을 예측하는데 있어 이러한 강우의 영향을 나타내는 지표의 설정은 중요한다. 본 연구에서는 범용토양유실공식(USLE)과 개정공식(RUSLE)의 강우침식도 R의 추정을 위해 1973년부터 1996년 까지 24년간 전국 53개 기상청 관측소의 강우 자료를 이용하였다. 본 연구에서 이용한 강우자료는 모든 관측소에 대해 동일 기간이며, 최근 24년간의 자료를 바탕으로 하고 있다. 본 연구의 최종 결과는 우리 나라의 등강우침식도로 나타내었다.

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