• Title/Summary/Keyword: SOIL EROSION

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Effects of Hillslope Treatments for Vegetation Development and Soil Conservation in Burned Forests (산불 피해 산림의 식생 발달과 토양 보존을 위한 사면 처리 효과)

  • Kim, Chang-Gi;Choung, Yeon-Sook;Joo, Kwang-Yeong;Lee, Kyu-Song
    • Journal of Ecology and Environment
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    • v.29 no.3
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    • pp.295-303
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    • 2006
  • Clear-cut followed by tree planting has been a conventional management practice in burned forests in Korea. Because this can considerably increase soil loss, hillslope treatments may be needed in order to improve soil stability at poorly regenerating areas. This paper reviews the effects of hillslope treatments, such as seeding, mulching and log erosion barriers, which have been applied to restore vegetation and conserve soil in burned forests in North America and Europe. Seeding has been the most common method for postfire restoration. However, the effects of seeding on vegetation cover and soil erosion are not clear and seeding with non-native species has been reported to inhibit regeneration of native vegetation. Mulching has been found to be effective at reducing soil erosion. However, this also can introduce non-native plant species and inhibit native plant regeration. Although studies on the effect of log erosion barriers are very few, it appears that log erosion barriers are effective in the period of little rainfall. Hillslope treatments for postfire restoration is not necessary for naturally regenerating areas and therefore, they should be restricted to the areas where regeneration potential is low and runoff and soil loss is considerable. Long-term monitoring is needed to assess the effectiveness of hillslope treatments on soil erosion, the introduction of non-native plant species and the inhibition of natural plant regeneration.

Applying Evaluation of Soil Erosion Models for Burnt Hillslopes - RUSLE, WEPP and SEMMA (산불사면에 대한 토양침식모형의 적용 평가 - RUSLE, WEPP, SEMMA)

  • Park, Sang Deog;Shin, Seung Sook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3B
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    • pp.221-232
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    • 2011
  • Applicability of three soil erosion models for burnt hillslopes was evaluated. The models were estimated with the data from plots established after tremendous wildfire occurred in the east coastal region. Soil erosion and surface runoff were simulated by the Water Erosion Prediction Project (WEPP) and the Revised Universal Soil Loss Equation (RUSLE) of application mode for disturbed forest areas and the Soil Erosion Model for Mountain Areas (SEMMA) developed for burnt hillslopes. Simulated sediment yield and surface runoff were compared with the measured those. In maximum value of sediment yield, three models was under-predicted and RUSLE and WEPP had difference of over two times. SEMMA showed the best model response coefficient, determination coefficient and the model efficiency. In application of models to the soil erosion according to the elapsed year after wildfire, all models were underestimated in initial stage disturbed by wildfire. Evaluation of models in this burnt hillslopes was shown the tends to under-predict soil erosion for larger measured values. Although a lot of sediment can be generated in small rainfall event as fine-grained soil of the high water repellency was exposed excessively right after wildfire, this under-prediction was shown that those models have a limit to estimate the weighted factors by wildfire.

Analysis on the Rainfall Driven Slope Failure Adjacent to a Railway : Flume Tests (강우로 인한 철도 연변사면의 활동분석 : 실내모형실험)

  • SaGong Myung;Kim Min-Seok;Kim Soo-Sam;Lee In-Yong
    • Journal of the Korean Geotechnical Society
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    • v.22 no.5
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    • pp.83-91
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    • 2006
  • Recently, the intensive rainstorm possibly induced by global warming plays a key role on the instability of railway adjacent slopes. The instability of slopes results as covering and loss of railway lines induced by slided soil mass. According to the site investigation on the failed slopes triggered by rainfall, low types of slope failure were observed: shallow, intermediate, gully erosion, and soil-rock interface failures. The observation reveals the different characteristics of slope failure depending on the thickness of soil layer, morphological features of slope, etc. Based upon the observations, flume tests were conducted to analyze the sliding mechanism of each failure. The variables of flume test are soil layer thickness, rainfall intensity, and morphology of slope under the constant condition of the percentage of fine, initial soil moisture content, slope angle and compaction energy. Test results show that shallow failure was mostly observed from the surface of the slope and caused by the soil erosion; in addition, compared to the other types of failure, the occurrence of initial erosion is late, however, the development of erosion is fast. In gully erosion failure, the collected water from the water catchment area helps erosion of the upper soil layer and transfer of residual corestone, which impedes the erosion process once the upper soil layers are eroded and corestone are exposed. The soil-rock interface failure shows the most fast initial erosion process among the failure types. Interestingly, the common feature observed from the different types of failure was the occurrence of the initial deformation near the toe of slopes which implies the existence of surbsurface flow along the downslope direction.

Development of Sediment Assessment Tool for Effective Erosion Control (SATEEC) in Small Scale Watershed (소유역의 효과적인 침식조절을 위한 유사평가 툴(SATEEC)의 개발)

  • Kyoung-Jae Lim;Joong-Dae Choi;Ki-Sung Kim;Myung Sagong;Bernard A. Engel
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.5
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    • pp.85-96
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    • 2003
  • The Revised Universal Soil Loss Equation (RUSLE) has been used in over 100 countries to estimate potential long-term soil erosion from the field. However, the RUSLE estimated soil erosion cannot be used to estimate the sediment delivered to the stream networks. For an effective erosion control, it is necessary to compute sediment delivery ratio (SDR) for watershed and sediment yield at watershed outlet. Thus, the Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed in this study to compute the sediment yield at any point in the watershed. To compute spatially distributed sediment yield map, the RUSLE was first integrated with the ArcView GIS and three area based sediment delivery ratio methods were incorporated in the SATEEC. The SATEEC was applied to the Bangdong watershed, Chuncheon, Gangwon Province to demonstrate how it can be used to estimate soil loss and sediment yield for a watershed. The sediment yield using USDA SDR method is 8,544 ton/year and 4,949 ton/year with the method by Boyce. Thus, use of watershed specific SDR is highly recommended when comparing the estimated sediment yield with the measured sediment data. The SATEEC was applied with hypothetical cropping scenario and it was found that the SATEEC can be used to assess the impacts of different management on the sediment delivered to the stream networks and to find the sediment source areas for a reach of interest. The SATEEC is an efficient tool to find the best erosion control practices with its easy-to-use interface.

Environmental Management by Using Weedy Plants

  • Oki, Yoko
    • Korean Journal of Weed Science
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    • v.18 no.2
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    • pp.95-105
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    • 1998
  • The positive functions of aquatic and terrestrial weedy plants were reviewed in terms of water purification, soil erosion prevention, salt-affected soil utilization, etc.. Introduced were several examples to utilize weedy plants for environment management by exploiting their positive functions.

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Risk Assessment of Soil Erosion in Gyeongju Using RUSLE Method (RUSLE 기법을 이용한 경주지역의 토양침식 위험도 평가)

  • Oh, Jeong-Hak;You, Ju-Han;Kim, Kyung-Tae;Lee, Woo-Sung
    • 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.

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

  • Kim, Jonggun;Yang, JaeE;Lim, Kyoung Jae;Kim, Sung Chul;Lee, Giha;Hwang, Sangil;Yu, Nayoung;Park, Youn Shik
    • Journal of Soil and Groundwater Environment
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    • v.22 no.6
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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.

Assessment of Soil Erosion Loss by Using RUSLE and GIS in the Bagmati Basin of Nepal

  • Bastola, Shiksha;Seong, Yeon Jeong;Lee, Sang Hyup;Shin, Yongchul;Jung, Younghun
    • 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.

Characteristics of the Soil Erosion with the Rainfall and Geotechnical Conditions (강우 및 지반조건에 따른 토양침식 특성)

  • Lee, Myung-Gu;Song, Chang-Seob
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.3
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    • pp.53-58
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    • 2011
  • This study is analyzed the characteristics of the soil erosion with the geotechnical conditions and rainfall conditions, such as the ground slope, the compaction ratio, rainfall intensity and duration of rainfall etc. To this ends, a series of model test are conducted on clayey sands. From the results, the variation of soil loss is analyzed with the geotechnical and the rainfall conditions. The amount of soil loss is decreased as the increase of compaction ratio and is increased as the ground slope, rainfall intensity and the duration of rainfall.

The Soil and Mineral Nutrient Erosion on the Floors of Vegetations (식피에 따른 토양과 무기양분의 유실)

  • 장남기;윤성모
    • Asian Journal of Turfgrass Science
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    • v.8 no.3
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    • pp.149-165
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    • 1994
  • This report was investigated on the soil and mineral nutrient erosions in comparison among the vegetation floors of M isranthus sisensis, Arternisia stelleriana, Rhododendron mucronula turn, Zoysia ja-ponira and Pinus deusitlora communities and the naked soil on Mt. Keum-hak in Cheolwon-Koon, The erosion of clay, silt, fine sand and coarse sand of the surface soils under the Z. japonira grass-land was far less then those of M. sinensis, A. stelleriana, R. murronulatum and P. densiflora com-munities and the naked soil, The loss of mineral nutrients due to the soil erosion was the lowest level in the Z. japonira grassland and the highest level in the P. densiflora forest and the naked soil, respectively.

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