• Title/Summary/Keyword: 토사

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The selection of soil erosion source area of Dechung basin (대청호유역의 토사유실 원인지역 선정)

  • Lee, Geun-Sang;Hwang, Eui-Ho;Koh, Deuk-Koo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.1997-2002
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    • 2007
  • This study selected soil erosion source area of Dechung basin by soil erosion estimation model and field survey for effective soil conservation planning and management. First, unit soil erosion amount of Dechung basin is analyzed using RUSLE (Revised Universal Soil Loss Equation) model based on DEM (Digital Elevation Model), soil map, landcover map and rainfall data. Soil erosion model is difficult to analyze the tracing route of soil particle and to consider the characteristics of bank condition and the types of crop, multidirectional field survey is necessary to choice the soil erosion source area. As the result of analysis of modeling value and field survey, Mujunamde-, Wondang-, Geumpyong stream are selected in the soil erosion source area of Dechung basin. Especially, these areas show steep slope in river boundary and cultivation condition of crop is also weakness to soil erosion in the field survey.

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Prediction of Watershed Erosion and Deposition Potentials (유역침식 및 퇴적 잠재능 예측모델 개발)

  • Son, Kwang-Ik
    • Journal of the Korean Society of Hazard Mitigation
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    • v.7 no.1 s.24
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    • pp.67-72
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    • 2007
  • A model for predicting potentials of land erosion and deposition over a natural basin was developed based on the mass balance principle. The program was developed based on sediment mass balance principle for each cell in a GIS. Sediment yield from a cell was estimated with RUSLE. The outflow sediment from a cell was calculated by multiplying the sediment yield of the cell by the sediment delivery ratio (SDR) of the cell. The outflow sediment from the upstream cell becomes the incoming sediment of the downstream cell. Therefore the erosion and deposition potential of each cell could be determined from the sediment mass balance i.e., the difference between the incoming and outflow of sediments of each cell. The developed model was validated by comparing the predicted sediment yields for three basins with measured data.

Application of SPOT 5 Satellite Image and Landcover Map for the examination of Soil Erosion Source Area (토사유실 원인지역 검토를 위한 SPOT 5 위성영상과 토지피복도의 활용)

  • Lee, Geun-Sang;Park, Jin-Hyeog;Hwang, Eui-Ho;Koh, Deuk-Koo
    • Journal of Korea Water Resources Association
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    • v.38 no.11
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    • pp.927-935
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    • 2005
  • Soil erosion by rainfall is important factor for basin management because it reduces reservoir capacity and breaks out the contamination of water caused by turbid water. Recently, soil erosion study with GIS is in progress but does not consider soil erosion source area. This study calculated soil erosion amount using GIS-based soil erosion model in Imha basin and examined soil erosion source area using SPOT 5 High-resolution satellite image and land cover map. As a result of analysis, dry field showed high-density soil erosion area and we could easily investigate source area using satellite image. Also we could examine the suitability of soil erosion area by applying field survey method in common areas such as dry field and orchard area those are difficult to confirm soil erosion source area using satellite image.

Sediments Yield Estimation of Gangwon Mountain Region in Korea (강원도 산간지역의 토사유출량 산정)

  • Kwon, Hyuk-Jae
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.127-132
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    • 2011
  • In this study, calculation results of sediments yield prediction models were compared with the amount of dredging data for the Inje, Gangwon mountain region of Korea. MSDPM and LADMP were used as a sediments prediction model which was calibrated and modified to calculate the sediments yield of Korean mountain region. Both sediments yield prediction models were modified by using Threshold Maximum Rainfall Intensity and Total Minimum Rainfall Intensity and correction coefficient. After comparing with the amount of dredging, it was found that results of MSDPM is more accurate than the results of LADMP. Difference of results of MSDPM and the amount of dredging is 27.6% and difference of results of LADMP and the amount of dredging is 50.6%. Both sediments yield prediction models which were calibrated in this study can be used to calculate the sediments yield for the Korean mountain region.

The Influence of Soil Content on the Settlement Behavior of Gravel Embankement (토사 함량에 따른 자갈 성토재료의 침하특성 분석)

  • Suhyung Lee;Jiho Kim;Beomjun Kim;Chanyoung Yune
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.11
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    • pp.41-49
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    • 2023
  • In this study, we analyzed the settlement characteristics of rockfill embankments mixed with soil by confirming the physical properties of soil materials mixed with silty materials and analyzing the compression characteristics of gravel materials according to the mixing ratio of soil materials. For this, we mixed silty materials into sandy soil to analyze the compression characteristics of soil materials, and we constructed a foundation by mixing various ratios of soil into rockfill materials with a particle distribution similar to that of river gravel, and conducted a one-dimensional compression experiment using a medium-sized chamber. As a result of the experiment, in the case of mixed soil materials, the Transition Fine Content (TFC) appeared in the range of 21~26% depending on the load condition, and in the case of rockfill materials mixed with soil, as the void filling ratio of soil in gravel samples increases, both total compression and creep compression decreases, but after a 50% mixing ratio, the settlement of amount increases again.

The evaluation of Soil Erosion Risk of Urban Area based on Geospatial Information (공간정보를 활용한 도심지 토사유실 위험도 평가)

  • Lee, Geun-Sang
    • Journal of Cadastre & Land InformatiX
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    • v.45 no.2
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    • pp.57-70
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    • 2015
  • Recently, soil erosion have been thickening from heavy rainfall according to climate change. These soil erosion is main reason to cause landslide, the water quality, agricultural counterproductivity and so on. Therefore, it is important to find out the main source area to cause soil erosion using geospatial data including DEM, soil map and land cover those are very sensitive to soil erosion modeling. This study evaluated soil erosion using RUSLE model. Hyoja 4-Dong and Pyonghwa 2-Dong among Wansan-Gu showed high as 10,869 ton/yr and 10,477 ton/yr respectively and Ua 2-Dong of Deokjin-Gu showed high as 17,603 ton/yr in soil erosion. And Hyoja 1-Dong and Pyonghwa 1-Dong among Wansan-Gu showed high as $1,485.7ton/km^2$ and $1,297.0ton/km^2$ respectively and Inhu 3-Dong of Deokjin-Gu showed high as $2,557.7ton/km^2$ in unit soil erosion that was applied to the evaluation of soil erosion potential. It is anticipated that achievement of this study can apply to forecast and prepare the risk of soil erosion and debris flow in urban area.

Review on Soil Erosion and Loss Management System of the Calgary City Government, Albert, Canada (캐나다 앨버트 주 캘거리 시의 토사관리제도에 관한 고찰)

  • Kim, Youngchul;Kim, Lee-Hyung;Hwang, Sung Woo
    • Journal of Wetlands Research
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    • v.17 no.2
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    • pp.163-175
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    • 2015
  • In this paper, soil erosion and soil loss management system (SMS) of the City of Calgary in Albert, Canada was reviewed. Regulatory basis supporting this soil management system, permit process and conditions, guidelines and principles for the SMS, and monitoring and repair duties, inspection were discussed. Permit process in the City of Calgary is handled mainly by Urban Development Division, in which special task force called CPAG (Coorporative Planning Application Group) (if necessary circulated through related subdivisions). Inspects all the permit conditions and decides permit or refusal, and LUM (Land Use and Mobility) advertises the approval, if there is no appeals, permit is released to developers. If permit is rejected, applicant can appeals Development Appeal Board, it can approve or reject. In addition to permit, the city has manual for soil management plan, which includes BMP selection, design, monitoring, maintenance, and inspection activities. Perfect SMS policy does not necessarily guarantee relieving the soil-particle related pollution problem, but in Korea, we have to recognize that construction works during development is potentially the most destructive stage of environmental pollution. The central and local governments must make preparations for the effective and tight regulations and ordinance which is appropriate for regional social-economic conditions.

Torrent Control Work Considering Stream Continuum and Sediment Delivery in a River Network (산지하천의 토사유출조절을 위한 마찰형 댐)

  • Kim, Suk-Woo;Chun, Kun-Woo;Marutani, Tomomi
    • 한국방재학회:학술대회논문집
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    • 2010.02a
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    • pp.58.2-58.2
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    • 2010
  • 우리나라의 산지하천은 경사가 급하고 유로연장이 짧아 집중호우 시에는 토사의 유출속도가 매우 빠르다. 따라서 산지하천에 주로 사방댐을 시공하여 유출토사를 억지하는데 중점을 두어왔으나, 계류생태계의 연속성을 차단한다는 문제점이 제기되어 왔다. 이 논문에서는 산지하천에 분포하는 하상기반암의 돌출이 토사의 이동 및 체류에 미치는 영향을 분석하고, 이를 응용하여 현지에 시공된 마찰형 댐 구간의 하상변동 모니터링 결과에 기초하여 계류생태계의 연속성을 유지하고 토사유출을 조절할 수 있는 방안에 대하여 고찰하였다.

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The Estimation of GIS-based Monthly Soil Erosion with Rainfall Weighting Value (강우가중치를 이용한 GIS기반 월별 토사유실량 평가)

  • Lee, Geun-Sang;Park, Jin-Hyeog;Chae, Hyo-Sok;Koh, Deuk-Koo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.3
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    • pp.65-73
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    • 2005
  • Because the geological features of Imha basin are composed of clay and shale layer, much soil particle flows into reservoir in shape of muddy water when it rains a lot. Therefore, turbidity data can be indirect-index to estimate the soil erosion of Imha basin. This study evaluated annual soil erosion using GIS-based soil erosion model and applied rainfall weighting value method by time-series rainfall data to estimate monthly soil erosion. In view of 2003 turbidity data, monthly soil erosion with rainfall weighting value is more efficient than monthly soil erosion with rainfall data.

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Analysis on Characteristics of Sediment Produce by Landslide in a Basin 2. Rainfall Event-based Analysis (유역 내에서의 산사태에 의한 토사발생특성 분석 2. 강우사상별 분석)

  • Yoo, Chul-Sang;Kim, Kee-Wook
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.3
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    • pp.147-154
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    • 2010
  • This study analyzed the characteristics of sediment produce by landslide triggered by rainfall. One-dimensional unsaturated groundwater model and infinite slope stability analysis were used to estimate the behavior of soil moisture and slope stability according to rainfall, respectively. Slope stability analysis was performed considering on soil depth and characteristics of trees. The results of the analysis on characteristics of sediment produce according to rainfall events showed that the sediment produce by landslide was mainly contributed to rainfall intensity and its temporal clustering. The results of the analysis on characteristics of sediment produce by extreme events showed that remaining rainfall amount of typhoon 'Rusa' was much more than that of the other extreme events, and thus this remaining rainfall was to contribute to sediment transportation. Additionally, only a small number of extreme events were found to cause most amount of sediment produce in a basin.