• Journal of Industrial Technology
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• v.19
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• pp.147-154
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• 1999

The soil loss by rainfalls or runoffs has been one of the main environment problems in 20th century. The soil loss cause the various problems those are decreasing of the agricultural productivity, desolating of pasture land and disturbing of water flowing. Therefore, it is very important to measure properly various factors those are affecting to soil loss and to recognize a seriousness of soil loss problem. In this study, we use the USLE(Universal Soil Loss Equation) as a basic approaching way for soil loss analysis in a watershed, and the GSIS(Geo-Spatial Information System) technique is applied to evaluate for factors those are related to the USLE. The results of this study are consisted of three parts those are to build up the various topographical information that is needed for analysis of wide area soil loss by using the USLE, to evaluate the factors those are needed to the USLE, to estimate the soil loss condition of subbasin in the watershed.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.619-625
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• 2006

Amount of soil loss is important information for the proper water quality management, In this research, annual average soil loss of the Geum River basin was estimated using RUSLE (Revised Universal Soil Loss Equation) and GIS (Geographic Information System). Input data were manipulated using ArcGIS ver. 8.3. From crop field which constitute 8.2% of the Geum River Basin, annual average soil loss was estimated as 53.6 ton/ha/year. From the rice paddy field which constitutes 20% of the Geum River Basin, soil loss was estimated as 33.5 ton/ha/year, In comparison, forestry area which constitutes 61.8% of the basin discharged 2.8 ton/ha/year, It could be known from this research that appropriate measures should be implemented to prevent excessive soil loss from the agricultural areas.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.109-125
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• 2017

This study aimed to develop a parcel-unit soil loss estimation tool embedded in Excel worksheet, USLExls, required for the design of contaminated farmland restoration project and to analyze the impact of the project carried out soil-filling work on soil loss. USLE method was adopted for the estimation of average annual soil loss in a parcel unit, and each erosivity factor in the USLE equation was defined through the review of previous studies. USLExls was implemented to allow an engineer to try out different combinations just by selecting one among the popular formulas by each factor at a combo box and to simply update parameters by using look-up tables. This study applied it to the estimation of soil loss before and after soil-filling work at Dong-a project area. The average annual soil loss after the project increased by about 2.4 times than before on average, and about 60 % of 291 parcels shifted to worse classes under the classification criteria proposed by Kwak (2005). Although average farmland steepness was lower thanks to land grading work, the soil loss increased because the inappropriate texture of the cover soil induced the soil erosion factor K to increase from 0.33 before to 0.78 after the soil-filling work. The results showed that the selection of cover soil for soil-filling work should be carefully considered in terms soil loss control and the estimation of change in soil loss should be mandatory in planning a contaminated farmland restoration project.

• Spatial Information Research
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• v.17 no.3
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• pp.261-268
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• 2009

This study accomplished to draw a soil erosion map and a grade map of soil loss hazard in Korea. RUSLE and Rainfall-runoff (R) factor, which was estimated by using the rainfall data observed in 59 meteorological stations from 1977 to 2006 (for 30 years). FARD was used to analyze the frequency, and the whole country R factor was estimated according to the frequency. In the analysis of estimating the whole country R factor, Nakdong river has the smallest vaule, but Han river has the biggest value. According to the result of analyzing soil loss, soil loss occurred in a grass land, a bare land and a field in size order, and also approximately 17.2 ton/ha soil loss happened on the whole area. The average soil loss amount by the unit area takes place in a bare land and a grass land a lot. The total amount of soil loss in 5-year-frequency rainfall yields 15,000 ton and, what is more, a lot of soil loss happens in a paddy field, a forest and a crop field. The grade map of soil loss hazard is drawn up by classifying soil loss hazard grade by 5. As a result of analyzing soil loss, the moderate area which is the soil loss hazard grade 2 takes up the largest part, 72.8% of the total soil loss hazard area, on the contrary, the severe soil loss hazard area takes up only $1,038km^2$ (1.1%) of the whole area. The severe soil loss hazard area by land cover shows $93.5km^2$ in a bare land, $168.1km^2$ in a grass land and $327.4km^2$ in a crop field respectively.

• Journal of the Korean GEO-environmental Society
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• v.20 no.3
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• pp.5-14
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• 2019

This study attempted to study the soil erosion dynamic in the Bagmati Basin of Nepal. In this study, an inclusive methodology that combines Revised Universal Soil Loss Equation (RUSLE) and GIS techniques was adopted to determine the distribution of soil loss in the study basin. As well, this study attempts to study the intensity of soil erosion in the seven different land use patterns in the Bagmati Basin. Soil loss is an associated phenomenon of hydrologic cycle and this dynamic phenomenon possesses threats to sustainability of basin hydrology, agriculture system, hydraulic structures in operation and overall ecosystem in a long run. Soil conservation works, and various planning and design of watersheds works demands quantification of soil loss. The results of the study in Bagmati Basin shows the total annual soil loss in the basin is 22.93 million tons with an average rate of 75.83T/ha/yr. The computed soil loss risk was divided into five classes from tolerable to severe and the spatial pattern was mapped for easy interpretation. Also, evaluation of soil loss in different land use categories shows barren area has highest rate of soil loss followed by agriculture area. This is a preliminary work and provides erosion risk scenario in the basin. The study can be further used for strategic planning of land use and hydrologic conservation works in a basin.

• Journal of Korean Society of Rural Planning
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• v.11 no.2 s.27
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• pp.9-19
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• 2005

The purpose of this study is to analyze the potential soil loss and hazard zone by the Revised Universal Soil Loss Equation(RUSLE) for preservation and management of land resources which is the base of ecosystem, and to grasp the relationship between RUSLE factors in the Nakdong River Basin. All thematic maps used in RUSLE are constructed through GIS and spatial analysis method derived from digital topographic maps, detailed soil maps, land-cover maps, and mean annual precipitation of 30 years collected respectively from National Geographic Information Institute, National Institute of Agricultural Science and Technology, and Ministry of Environment. The slope length of LS-factor that takes much times by the study area's wideness was calculated automatically through AML(Arc Macro Language) program developed by Van Remortel et al.(2001, 2003). The results are as follows; First, according to the soil loss estimation by the RUSLE, it shows that approximately 82% of the study area have relatively lower possibility of soil loss which is the 1 ton/ha in annual soil loss. While, 9.4% ($2,228km^2$) needed intensive and continuous management for soil loss. Because the amount of their annual soil loss was greater than 10 ton/ha that is optimum level suggested by Morgan(1995). For these areas, the author believe that a new approach which can minimize environmental impacts from soil loss through improvement of cultivation process and buffer forest zone should be applied. Second, according to the relationship between the RUSLE factors, topographical(LS-factor) and cover management(C-factor) conditions have a lot of influence on soil loss in case of the Nakdong River Basin. However, because of RUSLE factor's influence that affect to soil loss might be different based on the variety of spatial hierarchy and extent, it is necessary to analyze and evaluate factor's relationship in terms of spatial hierarchy and extent through field observations and further studies.

• Journal of the Korean Institute of Landscape Architecture
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• v.24 no.3
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• pp.115-132
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• 1996

The purpose of this study is to estimate the soil loss amount with Geographic Information System according to the land use change of Buju mountain area in Mokpo city. To estimate the soil loss, Universal Soil Loss Equation which is the most proper technique to predict soil loss in this site condition is adopted and IDRISI, a raster GIS software, is used. GIS application with USLE is very efficient to estimate soil loss accurately and fastly. In order to decide value and to find application method of USLE factors, we used existing rainfall erosion index, soil erodibility analysis, slope length, slope steepness, vegetation management and practices, which are rated by GIS through the analysis of various studies related USLE. The result of this study was compared with the previous other researches to verify our method of constructing numerical data of USLE's factors. The result of verification of our way showed significance for the soil loss in forest area. But the result of verification for the soil loss in forest area. But the result of verification for the soil loss of cultivated area showed some errors. It seems that this result was due to local variation of topographical map.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.3
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• pp.29-42
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• 2023

Universal Soil Loss Equation (USLE) is suggested and employed in the policy to conserve soil resources and to manage the impact of development, since soil loss is very essential to nonpoint source pollution management. The equation requires only five factors to estimate average annual potential soil loss, USLE is simplicity provides benefits in use of the equation. However, it is also limitation of the model, since the estimated results are very sensitive to the five factors. There is a need to examine the application procedures. Three approaches to estimate potential soil loss were examined, In the first approach, all factors were prepared with raster data, soil loss were computed for each cell, and sum of all cell values was determined as soil loss for the watersheds. In the second approach, the mean values for each factor were defined as representing USLE factors, and then the five factors were multiplied to determine soil loss for the watersheds. The third approach was same as the second approach, except that the Vegetative and Mechanical measure was used instead of the Cover and management factor and Support practice factor. The approaches were applied in 38 watersheds, they displayed significant difference, moreover no trends were detected for the soil loss at watersheds with the approaches. Therefore, it was concluded that there is a need to be developed and provided a typical guideline or public systems so that soil loss estimations have consistency with the users.

• Journal of Soil and Groundwater Environment
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• v.19 no.6
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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.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.313-324
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• 2011

The purpose of this study is to present the raw data for establishing the plan of top soil conservation in soil environment and preventing the soil loss by establishing the potential amount of soil loss using RUSLE. The results are as follows. To apply the RUSLE model, we calculated the potential amount of soil loss by using 5 factors; rainfall erosion factor(R), topographical factor(LS), soil erosion factor(K), land cover factor(C) and erosion control factor(P). The assessment map of soil loss was drawn up by classifying 5 grades. According to the soil loss estimation by the RUSLE, it showed that approximately 83.9% of the study area had relatively lower possibility of soil loss which was the 1 ton/ha in annual soil loss. Whereas, the 7.0% of the study area was defined as high risk area which was the 10 ton/ha in annual. Therefore, this area was needed that there was environment-friendly construction of farm land, improvement of cultivation environment and so forth. In future, if we will analyze the amount of soil loss of Gyeongju national park and Hyeongsan river watershed, we will offer the help to establishing the conservation plan of soil environment in Gyeongsangbuk-do.