• Title/Summary/Keyword: slope area

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A Study of Coarse Bed Materials in Small Streams in Rocky Mountains (로키 산맥 소하천의 조립질 하상 퇴적물에 관한 연구)

  • Kim, Jong-Wook
    • Journal of the Korean Geographical Society
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    • v.33 no.1
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    • pp.1-16
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    • 1998
  • This study surveyed intensively the relationships between grain size of coarse bed materials and some principal factors in channel system, drainage area and channel slope, in Rocky Mountains. The result of this research shows that there are statistically significant relationships between these factors. Generally, the grain size and the channel slope exponentially decreased in the study area with the increase in drainage area. However, there are great differences in grain size and channel slope between upstream and downstream channels. The boundary lines are commonly located at near the mouth of canyon. From these results, it can be concluded that the bed material characteristics and the channel slope are strongly influenced by the geological and geomorphological background of the drainage basin in this study area.

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A Comparative Study on the Habitat of Abies koreana WILSON between Mt. Jiri and Mt. Ha1la

  • Ihm, Byung-Sun;Lee, Jeom-Sook;Kim, Moon-Hong;Kim, Ha-Song
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2000.10b
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    • pp.60-64
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    • 2000
  • This examination of vegetation is conducted from lune to Oct. 1999 through on the spot survey, centering on the habitat of Abies koreana around Imgeolryeong, langteomok, and Jeseokbong in Mt Jiri and Yeongsil path and Seongpanak path in Mt. Halla. Species composition tables of the Abies koreana community by altitude and slope in Mt. Jiri and Mt. Halla are made based on the community composition tables examined in quadrat. The Abies koreana-Saso quelpaertensis community in a west slope of Mt. Halla is found that Abies koreana of 4-6m in height forms subtree layer and that of 8-9m in height the tree layer and it reflects a difference between community structure by slope and main composition species. While the tree layer of Abies koreana community is 12-14 in height around the area of 1, 290-1, 560m above the sea of Imgeolryong and path from Baekmudong to Jangteomok, it is 8-12m in height in the area of 1, 680-1, 780m above the sea of path from Jangteomok to Jeseokbong. It means that community structure depends on area and attitude. This study finds out that commonly appearing composition species similar to coverage and presence are Lepisorus thunberianus, Quercus mongolica, Soidago virga-aurea var. asiatica, Ligularia fischeri, Carex lanceolata, Clintonia udensis, Magnolia sieboldii, Betula ermani, Acer Pseudo-sieboldianum, As soil environment of surveyed area, pH of surveyed spots is similar in Mt. Jiri and Mt. Halla, electrical conductvity is higher in Mt Jiri, and contents of organic matter is relatively higher in a west slope of Mt. Jiri and Mt. Halla and lower in their south and west slopes. Contents of organic matter and total nitrogen show that the area of 1, 550m above the sea in a west slope of Mt. Halla is some higher. For pH and contents of total nitrogen and organic matter, Mt. Halla is higher than Mt. Jiri but for electrical conductivity , Mt. Jiri is relatively higher than Mt. Halla.

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A Comparative Study on the Habitat of Abies koreana Wilson between Mt. Jiri and Mt. Halla

  • lhm, Byung-Sun;Lee, Jeom-sook;Kim, Moon-Hong;Kim, Ha-Song
    • Plant Resources
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    • v.3 no.2
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    • pp.138-147
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    • 2000
  • This examination of vegetation is conducted from June to Oct. 1999 through on the spot survey, centering on the habitat of Abies koreana around Imgeolryeong, Jangteomok, and Jeseokbong in Mt Jiri and Yeongsil path and Seongpanak path in Mt. Halla. Species composition tables of the Abies koreana community by altitude and slope in Mt. Jiri and Mt. Halla are made based on the community composition tables examined in quadrat. The Abies koreana-Saso quelpaertensis community in a west slope of Mt. Halla is found that Abies koreana of 4-6m in height forms subtree layer and that of 8-9m in height the tree layer and it reflects a difference between community structure by slope and main composition species. While the tree layer of Abies koreana community is 12-14 in height around the area of 1,290-1,560m above the sea of Imgeolryong and path from Baekmudong to Jangteomok, it is 8-12m in height in the area of 1,680-1,780m above the sea of path from Jangteomok to Jeseokbong. It means that community structure depends on area and attitude. This study finds out that commonly appearing composition species similar to coverage and presence are Lepisorus thunberianus, Quercus mongolica, Solidago virga-aurea var. asiatica, Ligularia fischeri, Carex lanceolata, Clintonia udensis, Magnolia sieboldii, Betula ermani, Acer pseudo-sieboldianum. As soil environment of surveyed area, pH of surveyed spots is similar in Mt. Jiri and Mt. Halla, electrical conductivity is higher in Mt Jiri, and contents of organic matter is relatively higher in a west slope of Mt. Jiri and Mt. Halla and lower in their south and west slopes. Contents of organic matter and total nitrogen show that the area of 1,550m above the sea in a west slope of Mt. Halla is some higher. For pH and contents of total nitrogen and organic matter, Mt. Halla is higher than Mt. Jiri but for electrical conductivity, Mt. Jiri is relatively higher than Mt. Halla.

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Train Speed Control in Slope Area Using Infrared System (적외선 시스템을 이용한 경사 지역에서 열차 운행 속도 제어)

  • Sugiana, Ahmad;Sanyoto, Mulyo;Parwito, Parwito;Agrianto, Yanardian;Lee, Key Seo;Choy, Ick
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.6
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    • pp.635-644
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    • 2016
  • Train speed control is a vital part of train protection to build safe movement at an operation track. There is a special condition of track that needs more attention to protect the train, for example in slope area. Moreover, in developing country with vandalism problem, it requires to install minimalized equipment on the trackside. In addition, in tropical country, on tracksides it will be potentially pooling water that influences to the performance of trackside equipment. To address these problems, we propose the train speed control for slope area using infrared system. By installing on the pole configuration, the system offers a less challenging, economically sensible, minimalized installation of equipment on the trackside and reliability for heavy rain environment. This paper concentrates on the controlling train speed and measurement performance evaluation in slope area. The proposed train speed control system can monitor and control the speed in sloping area with maximum 3.6% and controlled speed about 20 km per h.

Sensitivity analysis of effective imperviousness estimation for small urban watersheds (도시 소유역 유효불투수율의 민감도 분석)

  • Kim, Dae Geun;Ko, Young Chan
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.2
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    • pp.181-187
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    • 2009
  • In this study, a runoff hydrograph and runoff volume were calculated by using the kinetic wave theory for small urban watersheds based on the concept of low impact development(LID), and the effective imperviousness was estimated based on these calculations. The degree of sensitivity of the effective imperviousness of small watersheds to the impervious to pervious area ratio, infiltration capability, watershed slope, roughness coefficient and surface storage depth was then analyzed. From this analysis, the following conclusions were obtained: The effective imperviousness and paved area reduction factor decreased as the infiltration capability of pervious area increased. As the slope of watersheds becomes sharper, the effective imperviousness and the paved area reduction factor display an increasing trend. As the roughness coefficient of impervious areas increases, the effective imperviousness and the paved area reduction factor tend to increase. As the storage depth increases, the effective imperviousness and the paved area reduction factor show an upward trend, but the increase is minimal. Under the conditions of this study, it was found that the effective imperviousness is most sensitive to watershed slope, followed by infiltration capability and roughness coefficient, which affect the sensitivity of the effective imperviousness at a similar level, and the storage depth was found to have little influence on the effective imperviousness.

Development of Landslide Hazard Map Using Environmental Information System: Case on the Gyeongsangbuk-do Province (환경정보시스템을 이용한 산사태 발생위험 예측도 작성: 경상북도를 중심으로)

  • Bae, Min-Ki;Jung, Kyu-Won;Park, Sang-Jun
    • Journal of Environmental Science International
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    • v.18 no.11
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    • pp.1189-1197
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    • 2009
  • The purpose of this research was develop tailored landslide hazard assessment table (LHAT) in Gyeongsangbuk-do Province and propose building strategies on environmental information system to estimate landslide hazard area according to LHAT. To accomplish this purpose, this research investigated factors occurring landslide at 172 landslide occurred sites in 23 city and county of Gyeongsangbuk-do Province and analyzed what factors effected landslide occurrence quantity using the multiple statistics of quantification method(I). The results of analysis, factors affecting landslide occurrence quantity were shown in order of slope position, slope length, bedrock, aspect, forest age, slope form and slope. And results of the development of LHAT for predict mapping of landslide-susceptible area in Gyeongsangbuk-do Province, total score range was divided that 107 under is stable area(IV class), 107~176 is area with little susceptibility to landslide(III class), 177~246 is area with moderate susceptibility to landslide(II class), above 247 area with severe susceptibility to landslide(I class). According to LHAT, this research built landslide attribute database and made 7 digital theme maps at mountainous area located in Goryeong Gun, Seongju-Gun, and Kimcheon-City. The results of prediction on degree of landslide hazard using environmental information system, area with little susceptibility to landslide(III class) occupied 65.56% and severe susceptibility to landslide(I class) occupied 0.51%.

Plant Community Structure by the Slope and Altitude of Tongdaesan Area in Odaesan National Park (오대산 국립공원 동대산지역의 사면. 해발고에 따른 식물군집구조)

  • Lee, Kyong-Jae;Cho, Woo;Hwang, Seo-Hyun;Yim, Kyong-Bin
    • Korean Journal of Environment and Ecology
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    • v.9 no.2
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    • pp.133-146
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    • 1996
  • This study was conducted to analyse plant community structure by the altityed and slope in Tongdaesan area, Odaesan National Park. Sixty-three plots(each plots size was 100m$^{2}$) were set up and PWINSPAN and DCA method were used for vegetational structure analysis. Division of community was cleared altitude than part of slope With increasing elevation the importance values of Quercus mongolica, Tilia amurensis increased, while those of Fraxinus mandshurica, Betula schmidtii, Cornus controversa decreased. Survey plots were divided into 6 groups by the TWINSPAN and DCA method. The divided groups are T. amurensis community(I), Q. mongolica community(II) of upper part of slope of east and west, Q. mongolica-T. amurensis community(III) of middle part of slope, Q. mongolica-F. mandshurica community(IV), Pinus densiflora-B. schmidtii-Carpinus laxiflora community(V) of low elevation of east, F. mandshurica-C. controversa community(VI)of low elevation of west. Also, vegetational change were showed slope of east and west in Tongdaesan except top area for the last twenty yeras.

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Slope Stability in Logging Areas Using Unmanned Aerial Vehicle Imaging (무인항공기 영상 촬영을 활용한 벌목지역의 비탈면 안정성 평가)

  • Kim, Tae-Wan;Yoo, Hyung-Sik;Park, Seok-In;Kim, Jae-Hong
    • Journal of the Korean Geotechnical Society
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    • v.38 no.7
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    • pp.39-47
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    • 2022
  • This study aims at evaluating the stability of disaster risks, such as schools, apartments, and geotechnical structures located around slopes in urban areas. The research conducted an aerial photography analysis on where the slope of the retaining wall behind 𐩒𐩒 High School in Gwangju collapsed in August 2018 due to heavy rain. In general, the overflow of rainwater has been managed through drainage channels around slopes during the rainy season, and the surface flow of rainfall was limited due to the presence of dense forests in the area. However, when the slope collapsed, a lot of water flowed out of the ground, and the saturated surface layer ground was destroyed. To analyze the cause, the changed terrain of the upper slope area, which could not be directly identified, was photographed using unmanned aerial vehicles. Digital Elevation Model by unmanned aerial vehicle shooting was performed by analyzing the slope map, calculating the direction of rainfall and the length and width of water-logged areas. The change in the instability of the slope over time due to a 10-day rainfall was also analyzed through numerical analysis.

Selection of Replantation Species in Roadside Cutting-slope Area of the Baekdu Range (백두대간 도로 절토비탈면의 녹화수종 선정)

  • Song, Hokyung;Jeon, Giseong;Kim, Namchoon;Park, Gwansoo;Kwon, Hyejin;Lee, Jihye
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.3
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    • pp.52-59
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    • 2007
  • This study was carried out to select proper species for early stage replantation in cutting-slope area of the Baekdu Range roadside. In the cutting-slope area and upper forest area of the cutting-slope area, sample plots of 46 were selected and their vegetations and environmental factors were investigated. We found total 90 species in the 46 plots. We found Festuca arundinacea in 27 plots of the 46 plots. We also found Lespedeza bicolor in 26 plots, Eragrostis curvula in 22 plots, Artemisia princeps var. orientalis in 19 plots, Erigeron annuus and Pinus densiflora in 15 plots, Lactuca indica var. laciniata in 14 plots, Miscanthus sinensis in 13 plots, Oenothera odorata, Commelina communis, and Humulus japonicus in 11 plots, Lespedeza cuneata in 10 plots, Salix koreensis and Salix hulteni in 9 plots, Festuca rubra, Youngia denticulata, Aster scaber, and Festuca arundinacea in 8 plots, Chenopodium album var. centrorubrum in 7 plots, Patrinia villosa and Erigeron canadensis in 6 plots, and Setaria viridis, Digitaria sanguinalis, and Dactylis glomerata in 5 plots.The dominancy of Festuca arundinacea, Eragrostis curvula, Lespedeza bicolor, Miscanthus sinensis, Pinus densiflora, Festuca arundinacea, Festuca rubra, Artemisia princeps var. orientalis, Erigeron annuus, Lespedeza cuneata, Dactylis glomerata, Salix koreensis, Alnus hirsuta, Pueraria thunbergiana, Medicago sativa, Lactuca indica var. laciniata, and Digitaria sanguinalis were 13.41% 11.87%, 4.88%, 4.56%, 3.38%, 2.29%, 2.14%, 2.14%, 1.99%, 1.95%, 1.54%, 1.47%, 1.44%, 1.37%, 1.15%, 1.13%, 1.07% in the roadside cutting-slope, respectively. The dominancy of Rhododendron mucronulatum, Lindera obtusiloba, Rhus trichocarpa, Quercus mongolica, Lespedeza bicolor, Rhododendron schlippenbachii, and Quercus serrata 22.15%, 13.36%, 13.14%, 12.03%, 11.74%, 11.20%, and 11.14% in shrub layer of the upper forest area, respectively. The species of Rhododendron mucronulatum, Lindera obtusiloba, Rhus trichocarpa, Rhododendron schlippenbachii, Zanthoxylum schinifolium, Weigela subsessilis, Stephanandra incisa, Rhamnus davurica, Ligustrum obtusifolium, Lindera erythrocarpa, Rosa multiflora, Rubus coreanus, Symplocos chinensis for. pilosa, Smilax china, Prunus sargentii, and Staphylea bumalda may be more helpful in stabilizing of the cutting-slope area and making harmony with the surrounding forest area.

Trends of Annual and Monthly FAO Penman-Monteith Reference Evapotranspiration (연별 및 월별 FAO Penman-Monteith 기준증발산 추세 분석)

  • Rim, Chang-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1B
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    • pp.65-77
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    • 2008
  • The effects of climatic changes owing to urbanization, geographical and topographical conditions on annual and monthly FAO Penman-Monteith (FAO P-M) reference evapotranspiration, and energy and aerodynamic terms of FAO P-M reference evapotranspiration were studied. In this study, 21 climatological stations were selected. The statistical methods applied for trend analysis are Spearman rank test, Sen's test, linear regression analysis and analysis of actual variation ratio. Furthermore, the cluster analysis was applied to cluster 21 study stations by considering the geographical and topographical characteristics of study area. The study results indicate that urbanization affects the trend and amount of FAO P-M reference evapotranspiration, energy term and aerodynamic term; however, the result of Sen's test indicates that urbanization does not significantly affect the magnitude of trend (Sen's slope). The energy term increased at study stations located in coastal area; however, decreased at study stations located in inland area. The topographical slope of study area did not significantly influence on the trend of energy term. The aerodynamic term increased in both coastal area and inland area, indicating much significantly increasing trend in inland area, and it was also affected by the topographical slope of the study area.