• Title/Summary/Keyword: Soil Loss

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A Study on the Determination of Loss Ratio in Dredged Soils (준설토의 유실율 결정에 관한 연구)

  • 김석열;김승욱;노종구
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.606-611
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    • 1999
  • Recently , the hydraulic fill method is commonly used in many reclamation projects due to lack of fill materialss. The method of hydraulic fill i recalmation is executed by transporting the mixture of water -soil particles into a relcaimed land through dredging pipes, then the dredged soil particels settle down in thewater orflow over an out flow weir with the water. The amount of the volume reductions of dredged soil is considered the sum of the overall settlement by descication shrinkage and self-weigth consolidation and the loss of soil particles flow over a weir. In the present study, hydrometer analysis was performed with the soil samples obtained bofore and after dredging to estimate the amount of soil particles residual at reclaimed area and the loss of soil particles , then it was suggested the method of determining the loss ratio of dredged soils from the tests results. The hydrometer analysis of in-situ soil samples showed that the loss ratio of dredged soils is lowest at the nearest point to dredge pipe and highest at the nearest point of out flow weir.

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Reduction of Soil Loss from Sloped Agricultural Field by using Organic Compost (유기퇴비를 이용한 급경사 농경지 토양유실 저감)

  • Koh, Il-Ha;Kang, Hui-Cheon;Kwon, Yo Seb;Yu, Chan;Jeong, Mun-Ho;Ji, Won Hyun
    • Journal of Soil and Groundwater Environment
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    • v.25 no.4
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    • pp.48-57
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    • 2020
  • The objective of this study was to investigate the feasibility of organic compost for reducing soil loss in 25% sloped farm land. For the study, laboratory and field experiment were performed. After nine weeks monitoring in pot test, hardness of the amended soil with organic compost (1%~3%, w/w) showed two times higher than the control soil. Furthermore, soil loss of that was decreased by 95% under rainfall simulation test. From the result of laboratory experiment, organic compost with 2% (w/w) was applied for field experimental plot. After six month from April to September, the amount of soil loss became 67% of the initial, and the growth of natural vegetation was not hampered. Therefore, organic compost can be used as amendment materials to reduce soil loss in sloped farmland.

Evaluation of GIS-based Soil Loss Amount in Considering Basin Characteristics (유역특성을 고려한 GIS 기반 토양침식량 평가)

  • Guak Dong-Wook;Cho Gi-Sung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.1
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    • pp.89-97
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    • 2006
  • Soil erosion has caused serious environmental problems which threaten the foundation of natural resources. In this paper, we chose RUSLE erosion model, which could be connected easily with GSIS and available generally in mid-scale watershed among soil erosion models, and extracted factors entered model by using GSIS spatial analysis method. First, this study used GIS database as soil map, DEM, land cover map and rainfall data of typhoon Memi (2003) to analyze soil loss amount of Dam basin. To analyze the changes of soil loss in considering basin characteristics as up-, mid- and downstream, this study calculated soil erodibility factor (K), topographic factors (LS), and cover management factor (C). As a result of analysis, K and LS factors of upstream showed much higher than those of downstream because of the high ratio of forest. But C factor of downstream showed much higher than that of upstream because of the high ratio of agricultural area. As a result of analysis of soil loss, unit soil loss of upstream is 4.3 times than soil loss of downstream. Therefore, the establishment of countermeasures for upstream is more efficient to reduce soil loss.

Integration of GIS-based RUSLE model and SPOT 5 Image to analyze the main source region of soil erosion

  • LEE Geun-Sang;PARK Jin-Hyeog;HWANG Eui-Ho;CHAE Hyo-Sok
    • Proceedings of the KSRS Conference
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    • pp.357-360
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    • 2005
  • Soil loss is widely recognized as a threat to farm livelihoods and ecosystem integrity worldwide. Soil loss prediction models can help address long-range land management planning under natural and agricultural conditions. Even though it is hard to find a model that considers all forms of erosion, some models were developed specifically to aid conservation planners in identifying areas where introducing soil conservation measures will have the most impact on reducing soil loss. Revised Universal Soil Loss Equation (RUSLE) computes the average annual erosion expected on hillslopes by multiplying several factors together: rainfall erosivity (R), soil erodibility (K), slope length and steepness (LS), cover management (C), and support practice (P). The value of these factors is determined from field and laboratory experiments. This study calculated soil erosion using GIS-based RUSLE 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 applying field survey method in common areas (dry field & orchard area) that are difficult to confirm soil erosion source area using satellite image.

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Estimation of Soil Loss Changes Using Multi-temporal Remotely-Sensed Imageries and GIS data (RS, GIS를 이용한 토양손설량의 경년변화 추정)

  • Kwon, Hyong-Jung;Hong, Sung-Min;Kim, Seong-Joon
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.34-38
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    • 2001
  • The purpose of this study is to estimate temporal soil loss change according to long-term land cover changes using GIS and RS. Revised USLE(Universal Soil Loss Equation) factors were made by using point rainfall data, DEM(Digital Elevation Model), soil map and land cover map. Past two decades land cover changes were traced by using Landsat MSS and TM data. Soil loss in 2000 increased $6.3\;kg/m^{2}/yr$ compared with that in 1983. This was mainly caused by the increased upland area.

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Assessment of Soil Loss at Military Shooting Range by RUSLE Model: Correlation Between Soil Loss and Migration of Explosive Compounds (RUSLE 모델에 의한 군사격장 피탄지 토양유실량 평가: 토양 유실과 오염 화약물질 이동 상관성)

  • Gong, Hyo-Young;Lee, Kwang-Pyo;Lee, Jong-Yeol;Kim, Bumjoon;Lee, Ahreum;Bae, Bumhan;Kim, Ji-Yeon
    • Journal of Soil and Groundwater Environment
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    • v.17 no.6
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    • pp.119-128
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    • 2012
  • The applicability and accuracy of Revised Universal Soil Loss Equation (RUSLE) model on the estimation of soil loss at impacted area of shooting range was tested to further the understanding of soil erosion at shooting ranges by using RUSLE. At a shooting range located in northern Kyunggi, the amount of soil loss was estimated by RUSLE model and compared with that estimated by Global Positioning System-Total Station survey. As results, the annual soil loss at a study site (202 m long by 79 m wide) was estimated to be 2,915 ton/ha/year by RUSLE and 3,058 ton/ha/year by GPS-TS survey, respectively. The error between two different estimations was less than 5%, however, information on site conditions should be collected more to adjust model coefficients accurately. At the study shooting range, sediments generated by rainfall was transported from the top to near the bottom of the sloping face through sheet erosion as well as rill erosion, forming a gully along the direction of the storm water flow. Coarser fractions of the sediments were redeposited in the limited area along the channel. Distribution characteristics of explosive compounds in soil before and after summer monsoon rainfall in the study area were compared with the erosion patterns. Soil sampling and analyses results showed that the dispersion of explosive compounds in surface soil was consistent with the characteristics of soil erosion and redeposition pattern of sediment movements after rainfalls.

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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Estimating Unsteady Soil Loss due to Rainfall Impact according to Rim Fire at California

  • Choi, Hyun;Kim, Gihong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.4
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    • pp.269-280
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    • 2017
  • Recently, in the United States, there has been short-term intensive rainfall due to El Ni?o and Rania. The Rim Fire was a wildland fire that was started in a remote canyon in Stanislaus National Forest in California. This portion of the central Sierra Nevada spans Tuolumne and Mariposa counties. This study is about estimating unsteady soil loss due to rainfall impact according to Rim Fire at California. It implies that caution needs to be taken in selecting the grid size for estimating soil loss using numerical modeling approach. Soil loss increased in all duration times before Rim fire. But it increased until 7 days and reduced or kept stable after that. Based on the 2014 average rainfall 1388 mm/yr, soil loss was estimated to be 247,518 ton/ha/yr before Rim Fire, and 9,389,937 ton/ha/yr after that.

Analysis of effect that land cover change get in Soil Loss by Forest fire (산불에 의한 토지피복변화가 토양유실에 미치는 영향분석)

  • 양인태;김재철;유영걸;오명진
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • pp.353-358
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    • 2003
  • Soil loss by the rains has effect on natural environment. But It is difficult to find out the data that is surveyed in watershed. In this paper, we chose USLE erosion model, which could be connected easily with GSIS and available generally, and extracted factors which is entered model by using GSIS spatial analysis method. Especially, As revised USLE model, It should be applied in watershed and as it calculated soil loss before forest fire and behind, it analysed the degree that it have an effect on soil loss. Each analyzed factors and the result of soil loss estimate consist of 22m-pixel size, we could identify soil loss by each pixel and distribution form.

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Evaluation on national environmental functionality of farming on soil loss using the USLE and replacement cost method (USLE모형과 대체법을 이용한 밭농사의 토양유실 저감기능 계량화 평가)

  • Hyun, Byung-Keun;Kim, Moo-Sung;Eom, Ki-Cheol;Kang, Ki-Kyung;Yun, Hong-Bae;Seo, Myung-Cheol;Sung, Ki-Seog
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.6
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    • pp.361-371
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    • 2002
  • Multifunctionality of agriculture has been an important international issue in terms of environmental benefits and public concerns. We calculated soil loss mass in national basis using the USLE, and attempted to evaluate its economical benefits by replacement cost method. Soil loss mass ranged from 1.4 to $18MT\;ha^{-1}\;yr^{-1}$ was fairly fitted to measured values for 13 cropping systems. In national basis, the factors in USLE were evaluated as: 429.4 for rainfall and runoff factor. R, 0.15 for soil erodibility factor, K, 1.72 for topographic factor, LS, 0.275 for cover and management factor, C, and 0.856 for support practice factor, P. The soil loss estimated from upland farming using the USLE was $26.1MT\;ha^{-1}\;yr^{-1}$, but soil loss from the bare soil was $110.8MT\;ha^{-1}\;yr^{-1}$, the ratio of soil loss from upland farming to bare soil was 23 percents. Function of reducing soil loss in comparison with the bare soil was $84.7MT\;ha^{-1}\;yr^{-1}$, of which national soil loss mass was 62.6 million MT per annum in south Korea. Agriculture economic replacement cost of soil loss reduction was 497 billion Wons(398 million dollars) for the cost of upland soil dressing. For conservational purposes to increase the environmental benefits of upland farming, the agricultural practice including contour, strip cropping, terracing and division ditches should be implemented.