• Title/Summary/Keyword: Mountain slope

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A Study on the value decision and the application method of USLE factors for the soil loss estimation in the large scale site development area using GIS-In the Case of BuJu Mountain in MokPo City- (GIS를 이용한 대규모 단지 개발지의 토양유실량 추정을 위한 USLE의 인지값 결정과 적용 방법에 관한 연구-목포시 부주산을 대상으로-)

  • 우창호;황국웅
    • 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.

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Numerical Simulation of the Flow Patterns with Sloping Forest Canopies (경사진 산림지형에서의 자연유동에 대한 수치해석)

  • Yoon, Hyun-Gi;Stock, David E.;Yoo, Ki-Soo;Chung, Myung-Kyoon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.3
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    • pp.173-180
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    • 2008
  • Diurnal variation of the flow over a forest canopy on a mountain slope is simulated numerically. In the daytime, the earth surface is heated by the solar radiation and the flow goes up the mountain due to the buoyancy force, and during the night, the air is drained downward along the slope owing to the cooling of the surface by radiation. In this flow process the forest canopy that consists of leaf region and the trunk region plays a dominant role as a momentum sink to the flow, thus the modeling of the leaf area region and trunk region is critical to the successful flow simulation. In the present study, a field measurement in an experimental forest in the State of Oregon in the United States is numerically analyzed. The resistance to the flow in the leaf region is directly related to the leaf area density (LAD), and the trunk is modeled as a cylinder.

Reinforcement Effect of Stabilizing Piles in Large-scale Cut Slops (대절토사면에 보강된 억지말뚝의 활동억지효과에 관한 연구)

  • 홍원표;한중근;송영석;신도순
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.65-81
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    • 2003
  • During the last few decades in Korea, the development of hillside or mountain areas has rapidly increased for infrastructure construction such as railroads, highways and housing. Many landslides have occurred during these constructions. Also, the amount and scale of damage caused by landslides have increased every year. In the case of Far East Asia including Korea, the damage of landslides is consequently reported during the wet season. In this paper, the effect of stabilizing piles on slope stability is checked and the behavior of slope soil and piles are observed throughout the year by field measurements in the large-scale cut slopes. In particular a large-scale cut slope situated on the construction site for the express highway in Donghae, Korea. First of all, The behavior of the slope soil was measured by inclinometers during slope modification. Landslides occurred in this area due to the soil cutting for slope modification. The horizontal deformations of slope soil gradually increased and rapidly decreased at depth of sliding surface indicating that the depth of sliding surface below the ground surface can be predicted. On the basis of being able to predict the depth of the sliding surface, stabilizing piles were designed and constructed in this slope. To ensure the stability of the reinforced slope using stabilizing piles, an instrumentation system was installed. The maximum deflection of piles is measured at the pile head and it is noted that the piles deform like deflection on a cantilever beam. The maximum bending stress of piles is measured at the soil layer. The pile above the soil layer is subjected to lateral earth pressure due to driving force of the slope, while pile below soil layer is subjected to subgrade reaction against pile deflection. As a result of research, the effect and applicability of stabilizing piles in large-scale cut slopes could be confirmed sufficiently.

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An Experimental Study on the Shear Characteristics of Rock Joint by Tilting Test (Tilting Test에 의한 암반절리면의 전단특성에 관한 실험적 연구)

  • 신방웅;신진환;이봉직
    • Journal of the Korean Society of Safety
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    • v.9 no.4
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    • pp.103-111
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    • 1994
  • Recently, rock slope in large scale is often accompanied with the construction of mountain roads and power plants. Rock in nature has a number of discontinuities such as bedding plane, joints, fracture zones and others. In order to improve rock slope stability, it is necessary to research shear properties of rock joint. In this paper shear properties of rock joint were studied by tilting test. Relations between properties of roughness and shear behavior of rock joint are investigated experimentally. The roughness are examined by compared with shear strength. Consequently, it becomes clear that the engineering properties and failure state modes of slope is different by JRC, and the peak friction angle is different by percent of filling.

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Rockfall analysis using simulation techniques- A practical application to, the Mt. Namsan Gyoungju in Korea

  • Lee, Jong-Yoon;Park, Hyeong-Dong
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.548-552
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    • 2003
  • During the last few decades, the frequency and distribution of rockfalls have been increased in Korea due the development of rock slope in mountain areas. Although the scale of, falling block of rockfall was small, there were some casualties of lives and loss of properties. In order to reduce damage from rockfall, analysis on rock slope indanger of rockfall should be carried out. Thus, the simulation softwares for rockfall behavior analysis have been introduced. In this study, geotechnical investigation and input data for rockfall simulation are described with the comparison among four commercially available rockfall simulation softwares. Finally, rockfall simulation works are described by exmining a case of inaccessible rock-slope of potential rockfall in Korea.

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Study on Risk Analysis of Debris Flow Occurrence Basin Using GIS (GIS를 이용한 토석류 발생유역 위험성분석에 관한 연구)

  • Jun, Kye-Won;Oh, Chae-Yeon
    • Journal of the Korean Society of Safety
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    • v.26 no.2
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    • pp.83-88
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    • 2011
  • Annually, many parts of the Korea have been damaged from the localized heavy rain and/or typhoons which peak between June and September, which result in extensive financial and human loss. Especially, because the most area of Gangwon province is composed of the steep slope mountains, the damages by the debris flow or land-sliding are more frequent and the frequency has been increased. To analyze the characteristics and causes of these debris flow disasters, lots of study are recently being conducted through database of weather, hydrologic, soil etc using a GIS or remote sensing. In this study, we applied GIS method to analyze the risk of the debris flow area. With the statistical analysis and infinite slope stability model(SINMAP), the debris flow risk level of the mountain slope was generated. As a result, the GIS statistical analysis showed high correlation that former model of SINMAP in determining the debris flow risk area.

Influence on forest fire spread & intensity on fuel type of burnt area. (산불피해지역 연료형태가 산불연소에 미치는 영향)

  • Lee, Si-Young;Lee, Myung-Woog;Yeom, Chan-Ho;Kwon, Chun-Geun;Park, Houng-Sek;Lee, Hae-Pyeong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.321-324
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    • 2008
  • Forest fire danger rate of thinning area was lower than that of non thinning area, because height rate of leewardside in burned stem of tree, damage rate of crown and mortality of tree in thinning area were 30.8%, 37% and 48.4% lower than that in non-thinning area, respectively. Intensity of forest fire varied depending upon topographical condition up slope, down slope, aspect, location as well as species, breast height diameter and forest tree density. Especially, a mountaintop area was burned down when forest fire was spread to up slope ridge of mountain.

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On the Dominance-Diversity in the Forest Vegetation of Mt. Seolag (설악산 삼림식생의 우점도 다양성에 관하여)

  • Choi, Ki Ryong
    • Journal of Plant Biology
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    • v.27 no.1
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    • pp.25-32
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    • 1984
  • A study on the dominance-diversity of forest vegetation in Mt. Seolag was conducted from May 1981 to Aug. 1983. Based on the field data, the dominance-diversity curves were for 16 sites including slopes and vallies. The curves are grouped in two types, lognormal distribution at the sites of mature vegetation and geometric series at the disturbed or rocky sites. It seems that the curves express the nature of their ecocline, by the hypotheses of some investigators, i.e. Random Niche hypothesis, Niche Pre-emption hypothesis, Lognormal distribution and Logarithmic series. The dominance concentration among the southern, northern and western slope, H'=1.282 at southern slope and H'=1.385 at western slope. Dominance-diversity curves of 16 sites showed Preston's lognormal distribution with small variations among them. It seems that the dominance diversity reflects the differences in the coenocline of their sites. The top 10 dominant species in species sequence of 113 tree species in whole the mountain, were noticed: Quercus mongolica, Pinus densiflora, Acer pseudo-siebold anum, Quercus serrata, Carpinus laxiflora, Styrax obassia, Fraxinus rhynchophylla, Tilia amurensis, Lindera obtusiloba and Abies holophylla in order.

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A Case Study on The Stability and Reinforcement Method at a Rock Slope (암반사면의 안정성검토 및 보강방안에 관한 사례연구)

  • Chun, Byung-Sik;Lee, Seung-Eun;Kong, Jin-Young;Lim, Joo-Heon
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1369-1375
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    • 2006
  • This study analyzes stability and the reason of slope failure about cut slope on stony mountain in Acheondong, Guri and suggests the reasonal reinforce method. Based on the results of the subsurface exploration, laboratory tests, and the numerical analysis of finite element method, the potentials of plane and wedge failure are highly estimated. The safety factor was 1.2 under dry and 1.06 wet condition. The most proper reinforce method to raise the safety factor more than 1.5 was the way to control displacement by using step retaining wall, earth anchor, wire mesh, and rock anchor.

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Feasibility of the Lapse Rate Prediction at an Hourly Time Interval (기온감률의 일중 경시변화 예측 가능성)

  • Kim, Soo-ock;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.1
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    • pp.55-63
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    • 2016
  • Temperature lapse rate within the planetary boundary layer shows a diurnal cycle with a substantial variation. The widely-used lapse rate value for the standard atmosphere may result in unaffordable errors if used in interpolating hourly temperature in complex terrain. We propose a simple method for estimating hourly lapse rate and evaluate whether this scheme is better than the conventional method using the standard lapse rate. A standard curve for lapse rate based on the diurnal course of temperature was drawn using upper air temperature for 1000hPa and 925hPa standard pressure levels. It was modulated by the hourly sky condition (amount of clouds). In order to test the reliability of this method, hourly lapse rates for the 500-600m layer over Daegwallyeong site were estimated by this method and compared with the measured values by an ultrasonic temperature profiler. Results showed the mean error $-0.0001^{\circ}C/m$ and the root mean square error $0.0024^{\circ}C/m$ for this vertical profile experiment. An additional experiment was carried out to test if this method is applicable for the mountain slope lapse rate. Hourly lapse rates for the 313-401m slope range in a complex watershed ('Hadong Watermark 2') were estimated by this method and compared with the observations. We found this method useful in describing diurnal cycle and variation of the mountain slope lapse rate over a complex terrain despite larger error compared with the vertical profile experiment.