• Title/Summary/Keyword: 토사유실모델

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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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The Influence Analysis for Soil Loss in Reservoir Slant using GIS-based Soil Loss Model (GIS기반 토사유실모델을 이용한 저수지 사면의 토사유실 영향 분석)

  • Lee, Geun-Sang;Park, Jin-Hyeog;Hwang, Eui-Ho;Koh, Deuk-Koo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.3
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    • pp.108-117
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    • 2004
  • Soil particles from rainfall flow into reservoir and give lots of influence in water quality because the geological conditions and landcover characteristics of Imdong watershed have a weakness against soil loss. Especially, reservoir slant is indicated by the main source area of soil loss. This study selected RUSLE model that could apply GIS and satellite image to evaluate the contribution rate of soil loss in reservoir slant. And we carried out an on-the-spot survey for the range, width and condition of reservoir slant that give much influences to the accuracy of soil loss. As the result of evaluation to the influence of soil loss in reservoir slant, it showed 2.64% in comparison with Imdong watershed. In view of these results, the influence of soil loss in reservoir slant was evaluated in low comparing with Imdong watershed relatively.

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Evaluation of GIS-based Soil Erosion Amount with Turbid Water Data (탁수자료를 이용한 GIS 기반의 토사유실량 평가)

  • Lee, Geun-Sang;Cho, Gi-Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.12 no.4 s.31
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    • pp.75-81
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    • 2004
  • Because geological types and land cover conditions of Imha basin have a very weak characteristics to soil erosion, most soil particles (low into river and bring about high density turbidity in Imha reservoir when it rains a lot. This study used GIS-based RUSLE model and analyzed soil erosion to make basic data for the countermeasures of turbidity reduction in Imha reservoir. Total soil erosion amounts was evaluated as 5,782,829 ton/yr using rainfall data(2003) and especially Dongbu-basin was extracted as most source area or soil erosion among Imha sub-basin. Also it was evaluated that soil erosion amount by RUSLE model was suitable by applying turbidity survey data.

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The Comparative Estimation of Soil Erosion for Andong and Imha Basins using GIS Spatial Analysis (GIS 공간분석을 이용한 안동·임하호 유역의 토사유실 비교 평가)

  • Lee, Geun Sang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.2D
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    • pp.341-347
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    • 2006
  • Geographically Imha basin is adjacent to Andong basin, but the occurrence of turbid water in each reservoir by storm events shows big differences. Hence, it is very important to identify the reason for these large differences. This study compared and analyzed soil erosion using the semi-empirical soil erosion model, RUSLE for both Imha and Andong basin, especially with emphasis on high-density turbid water. The agricultural district, which is the most vulnerable to soil erosion, was intensively analyzed based on land cover map produced by Ministry of Environment. As a result, the portion of the agricultural area is 11.88% for Andong basin, while it is 14.95% for Imha basin. Also all RUSLE factors excepts practice factor turned out to be higher for Imha basin. This means that the basin characteristics such as soil texture, terrain, and land cover for Imha basin is more vulnerable to soil erosion. Estimation of soil erosion by RUSLE for Andong and Imha basin is 1,275,806 ton and 1,501,608 ton, respectively, showing higher soil erosion by 225,802 ton for Imha basin.

Parcel based Information System for Sediment Disaster by using Mobile GIS (모바일 GIS를 이용한 필지별 토사재해정보시스템 개발)

  • Lee, Geun-Sang;Choi, Yun-Woong
    • Journal of Cadastre & Land InformatiX
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    • v.46 no.1
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    • pp.59-74
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    • 2016
  • The collapses of retaining walls or embankments, the soil erosion and landslides around urban areas are occurring by heavy rainfalls because of the recent climate change. This study conducts the soil erosion modeling, while applying the spatial information such as soil maps, DEM and landcover maps to the RUSLE model. Especially this study draws up the soil erosion grade map and the unit soil erosion grade map by parcels through coupling the soil erosion with the cadastral map, and by that can calculate the number of parcels by soil erosion grades. Also the sediment disaster information system based on the mobile GIS is developed to identify the soil erosion grades of site in the urban plannings and the construction fields. The sediment disaster information system can identify the present conditions of the registers of lands, buildings and roads, and confirm the RUSLE factors, the soil erosion, the sediment disaster grades by parcels. Also it is anticipated that this system can support the sediment disaster work of site effectively through searching the locations and attributes of the specific parcels by Administrative Dong and the soil erosion grades.

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.

Application and Comparative Analysis of SWAT and HSPF for Developing Turbidity Management in Imha-Andong Watershed (임하.안동 유역에서 탁수 관리를 위한 SWAT 및 모형 적용 및 비교 분석)

  • Son, Kyong-Ho;Lee, Hyi-Suk;Kim, Jeong-Kon;Kim, Ik-Jae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.183-187
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    • 2007
  • 유역에서 토사유실로 인한 고농도 탁수의 발생은 현장조사와 수치모형 해석으로 평가될 수 있다. 하지만 현장조사로는 토사유실을 정량화하기에는 제한적이므로 수치모형의 적용이 요구된다. 토사유사예측을 위한 모형 적용 시, 시공간 분석을 위해서 물리적 기반 분포형 혹은 준 분포형 모형이 선호된다. 본 연구에서는 임하 안동 유역의 유출 및 토사유실 분석을 위하여 SWAT 모형 및 HSPF 모형을 적용하였다. 두 모델의 유량 검 보정은 유역 내에 수위 관측 자료(1999년${\sim}$2006년)를 이용하였으며 유사농도는 2006년 하절기 현장 조사를 통해 보정되었다. SWAT 모형의 일별 유출량 변화에 대한 Nash-Sutcliffe 효율계수는 $0.43{\sim}0.76$의 범위로 전반적으로 측정 유량을 잘 모의 하는 것으로 나타났다. HSPF 모형은 SWAT 모형과 마찬가지로 높은 효율의 일별 유출량 예측성을 보였다. 그러나 두 모델은 첨두 유량을 과소산정 하였다. 두 모형의 그래픽 분석결과 측정 유사 농도를 잘 모의하였고, 특히 HSPF 모형은 강우사상에 따른 시간별 실측값의 경향을 잘 예측하였다. 두 모형의 예측성 비교 시, 유출량은 SWAT 모형이 HSPF 모형이 비해 더 잘 모의하였으며 유사 농도는 HSPF 모형이 더 높은 정확성을 보였다. 본 연구의 결과는 향후 각 소유역별로 탁수를 유발하는 토사 유실량 평가, 유역의 토사유실 저감대책 효과분석 및 저수지 모형과의 연계를 통한 유입된 탁수의 효율적인 관리대책 수립에 이용될 것으로 사료된다.

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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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GIS-based strategic approach for the estimation of soil erosion (토사유실평가를 위한 GIS기반의 전략적 접근 방법)

  • Lee, Geun-Sang;Koh, Deuk-Koo;Je, Seong-Jin
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.413-416
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    • 2006
  • This paper presents a strategic approach to effective soil conservation planning and management. To do this, the soil loss model, Revised Universal Soil Loss Equation (RUSLE) was used to quantify soil erosion in two basins (Andong and Imha basin), which are distinct in terms of sedimentation in the reservoir of each basin. Areas with high soil erosion potential were analyzed on the basis of land surface characteristics handled by geographic information system (GIS), especially dividing the basin into several sub-basins and then examination was emphasized near the river channel (water-pollutant buffering zone), along which human activities are large. Modeling results show the approach suggested herein provides a basis and guideline for choosing prior erosion risk areas to be examined for soil conservation planning and management. Also, this approach is relatively simple and has wide practical applicability.

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GIS-based Survey methodology of turbid water in basin (댐유역 탁수원인 조사를 위한 GIS 자료구축 방향)

  • Lee, Geun-Sang;Yum, Kyung-Taek;Hwang, Eui-Ho;Koh, Deuk-Koo
    • 한국공간정보시스템학회:학술대회논문집
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    • 2007.06a
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    • pp.240-245
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    • 2007
  • 본 연구에서는 2006년 태풍 에위니아 이후 고탁수 문제가 발생하였던 소양호유역을 중심으로 탁수원인이 되는 토사유실지역을 효과적으로 선정하기 위한 방법론을 제시하였다. 특히 토사유실모델을 통해 분석된 결과와 함께 하천주변 대단위 농경지 특성, 경사지 및 제방 특성 등을 고려하여 탁수원인지역을 선정하는 기법을 소개하였다. 또한 농경지별 작물종류 자료구축을 위한 모바일 GIS 자료구축 방법 및 지질코드별 가중치평가 기법을 제시함으로서 보다 체계적인 탁수원인지역 조사가 가능하게 되었다.

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