• Title/Summary/Keyword: Slope and aspect

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Calculating the Actual Surface Area for Gangneung Forest Fire Area Using Slope-Aspect Algorithm (Slope-Aspect 알고리즘을 활용한 강릉시 산불 피해지역 실표면적 산출 방법)

  • Jeong, JongChul
    • Journal of Cadastre & Land InformatiX
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    • v.52 no.1
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    • pp.95-104
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    • 2022
  • This study aims to find the exact area of the forest fire in Okgye-myeon, Gangneung, April 4, 2019. Since there is a gradient in our country's forests, we should find a surface area that takes into account The 5th numerical clinical map provided by the DEM and the Korea Forest Service provided by the National Geographic Information Service was used. In DEM, the center point of each pixel was created and all points were connected. The length of the connecting line is determined by the spatial resolution of the pixel and the cosine value, and the surface area is obtained along with the height value, which is called the Slope-Aspect algorithm. The surface area and floor area of the forest were shown according to the tree species and types of forest, and their quantitative numerical differences proved the validity of this study.

Influence of Elapsed Years and Physical Properties on Vegetation Invasion of Forest Road Slope (임도시공경과년수 및 물리적 특성이 임도사면의 식생 침입에 미치는 영향)

  • Lee, Joon Woo;Choo, Gab-Chul;Choi, Yeon Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.1
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    • pp.28-34
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    • 2002
  • This study was carried out to analyze the effects of elapsed years and physical properties on invaded vegetation of forest road slope. For the study, 8 forest roads in Asan-si of Chungcheongnam-do were selected and 15 factors that might influence on vegetation invasion were analyzed. In generally, vegetation coverage of slope have increased with the elapsed years. But invasion species have decreased in the cut-slope and increased in fill-slope. There was no significant correlation between rate of vegetation coverage and elapsed years, but rate of vegetation coverage was strongly related with slope aspect. And the species of invasion vegetation affected mostly by the elapsed years and slope aspect among the physical properties.

Forest Structure in Relation to Slope Aspect and Altitude in Osaek-Taech'ongbong-Shinhungsa Area at Soraksan National Park (설악산국립공원 오색-대청봉-신흥사지역의 사면방향과 해발고에 따른 산림구조)

  • 박인협;류석봉;최영철
    • Korean Journal of Environment and Ecology
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    • v.11 no.4
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    • pp.486-492
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    • 1998
  • The forests of Osaek-Taech'ongbong-Shinhungsa district in Soraksan National Park was studied to investigate forest structure of tree strata in relation to aspect and altitude of the slope. Excepting the main ridge area which has tyoical environmental condition, tree siwe in canopy of the wouthern slope was smaller, density in canopy of the southern slope was higher and species diversity in tree stratum of the southern slope was lower as compared those of the northern slope of same elevation belts. Elevation trend was found for forest structure of the southern slope where geographical features were similar among elevation belts. With incleasing elevation of the southern slope, basal area of canopy and understory increased. With increasing elevation of the southern slope, importance values of Quercus mongolica, Styrax obassia, and Lindera obtusiloba decreased while those of Pinus koraiensis, Betula ercani, Acer tschonoskii var. rubripes and Rhododendron schlippenbachii increased. According to cluster and ordination analysis, the studied forests was classifide into Quercus mongolica community at the low, middle and high elevation belts of the southern slope and the low and middle elevation belts of the northern slope, Betula ermani community at the elevation belt of the northern slope, and Abies koreana community at the top area.

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Estimation of Solar Radiation Distribution Considering the Topographic Conditions at Jeju Island (지형조건에 따른 제주도의 일사량 분포 추정)

  • Park, Jin Ki;Park, Jong Hwa
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.1
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    • pp.39-48
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    • 2013
  • The solar radiation is the primary energy source that drives many of the earth's physical and biological processes and climate change. Understanding its importance to the solar radiation observation is a key to understanding a broad range of natural processes, agricultural, energy and human activities. The purpose of this study is to estimate solar radiation using sunshine duration, and to estimate distribution of solar radiation using a topography factor considering surface slope and aspect in complex terrain. The result of regression analysis between ratio of solar radiation and sunshine duration from 2001 to 2010 shows high $R^2$ value of 0.878. Regression analyses indicated that topographic attributes including elevation, slope and aspect had significant effects on solar radiation. The variation of topographic factor with aspect and slope for the summer and winter are considered. The highest month of daily mean solar radiation at Jeju island appears in April of 20.61 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$, and the lowest month appears in December of 6.90 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$. These results provided useful quantitative information about the influence of topography on solar radiation in the island region.

Analysis of relationship between spatial distribution of Pinus densiflora and topographical factors (소나무 공간분포와 지형인자간의 상관성 분석)

  • Kim, Tae-Min;Lee, Woo-Kyun;Jung, Sung-Eun;Kwak, Han-Bin
    • Spatial Information Research
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    • v.16 no.3
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    • pp.359-372
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    • 2008
  • This research estimated Pinus densiflora distribution and suggested an optimal grid size of DEM for ecologically better explaining spatial distribution and appearance pattern of Pinus densiflora and analyze appearance frequency of Pinus densiflora by topographical factors. And this work ultimately aimed at topographically analyzing spatial distribution of Pinus densiflora by comparing impact of topographical factors. The aspect was analyzed in detail, east, west, south, north, from DEM with 1m grid size, and simply, east, west, south or east, south from DEM with bigger grid size. As a result of distribution of Pinus densiflora by aspect, Pinus densiflora appeared in all aspect with smaller grid size, while distribution in specific aspect decreased with bigger grid size. The analysis of appearance frequency with 100m grid size represented spatial distribution characteristics of Pinus densiflora as visual interpretation showed. The results of comparing impact of aspect, slope, TWI proved that aspect have more impact on distribution of Pinus densiflora than slope and there was not enough a difference between impact of slope and TWI.

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The Evaluation of Failure Factors on Cutting Slopes of Forest Road by Quantification Theory(II) (수량화 II 류에 의한 임도절토사면의 붕괴요인 평가)

  • Cha, Du-Song;Ji, Byoung-Yun
    • Journal of Forest and Environmental Science
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    • v.18 no.1
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    • pp.7-14
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    • 2001
  • On the basis of data obtained from forest road collapsed due to a heavy rainfall, this study carried out to evaluate the cutting slope failure factors of forest road by using Quantification theory(II). The results were summarized as follows. The factors on cutting slope failure was ranked in the order of cutting slope length, soil type, aspect, cutting slope gradients and slope gradients. And the slope failure was mainly occurred under such conditions as cutting slope length longer than 8m, soil type with soil, aspect of N, cutting slope gradients steeper than 600 and slope gradients greater than $35{\sim}40^{\circ}$.

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Analysis of Landslides Characteristics in Korean National Parks (우리나라 국립공원지역의 산사태 발생특성 분석)

  • Ma, Ho-Seop;Jeong, Won-Ok
    • Journal of Korean Society of Forest Science
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    • v.96 no.6
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    • pp.611-619
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    • 2007
  • This study was carried out to analyze the landslide characteristics and forest environment factors on the landslide area of 7 national parks in korea. The results obtained from this study were summarized as follows; The total number of landslide occurrence was 44 areas. The average length of the landslides scar was 152 m, average width was 17 m. And the average area was $2,818m^2$. The factors influencing landslides were highly occurred in Metamorphic rock, mixed forest type. And also, $30{\sim}35^{\circ}$ in slope gradient, NE in slope aspect, slope higher than 1,000 m, concave (凹) type in vertical and cross slope, 0 ordered stream. The main factors affecting landslide area in stepwise regression analysis were sheet type in landslided shape, NE in slope aspect, 2 ordered stream, SE in slope aspect, slope gradient and complex slope in cross slope type in order of regression coefficient.

Analysis of factors affecting vegetation cover for stabilization of granite weathered soil forest road cut slopes

  • Seong-Man Kim;Sung-Min Choi;Ye Jun Choe;Yun-Jin Shim;Joon-Woo Lee
    • Korean Journal of Agricultural Science
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    • v.49 no.4
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    • pp.861-871
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    • 2022
  • This study was conducted to improve the stability of cut slopes of forest roads in granitic weathered soil areas. The study area is a national forest road (road length 28.48 km) in Pyeongchang-gun, Gangwon-do. After data collection, a statistical analysis was performed using IBM SPSS (Ver. 26.0). First, the correlation analysis showed that structure, slope position, soil erosion, slope, and aspect (N, S) were correlated with vegetation coverage (p < 0.05). Elapsed years, slope distance, and aspect (E, W) were found to have no correlation with vegetation coverage. (p > 0.05) Second, one-way ANOVA and Kruskal-Wallis test results showed that vegetation coverage was worse when the slope was located at the top or the middle of the slope than at the bottom of the slope. In addition, the site with sheathing and gabions showed good vegetation coverage when compared with the site without structures. In the case of soil erosion, areas with severe damage and moderate damage showed worse vegetation coverage. Therefore, it is necessary to strengthen the slope angle of the cut soil of the granitic weathered soil area from 1 : 0.5 - 1.2 to 1 : 0.8 - 1.5. In addition, structures such as sheathing and gabions should be installed on granitic weathered land.

A Study on Change of NDVI According to the Terrain Element (지형요소에 따른 NDVI의 변화에 관한 연구)

  • Sung, Chun-Ja;Jung, Jong-Chul
    • Journal of the Korean Association of Geographic Information Studies
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    • v.6 no.2
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    • pp.92-100
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    • 2003
  • Analysis and results of the relationship between the NDVI and terrain element such as elevation, slope, aspect in Chunahn city area are as follows. It does not show the linear relationship between NDVI and analyzed terrain element such as elevation, slope, aspect, etc. and there is a trend such that the deviation of NDVI is decreased as the elevation and slope is increased. It appears that there is trends such that the distribution range of NDVI is discontinuously changed as the elevation and slope is increased. The distribution range of NDVI is discontinuously decreased based on about 50m and 100m borderline in elevation case, and slope $10{\sim}20^{\circ}$ borderline in slope case, respectively. Any special trend is discovered in the relationship between aspect and NDVI.

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An Analysis of the Types of Slope Concepts in Math Textbooks of Middle School (중학교 수학 교과서에 제시된 기울기 개념에 관한 유형 분석)

  • Kang, YoungRan;Cho, CheongSoo
    • Journal of the Korean School Mathematics Society
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    • v.22 no.4
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    • pp.351-367
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    • 2019
  • Slope is an important mathematical concept that is connected to advanced mathematics as well as a basic concept as an indicator of the steepness of a straight line. The purpose of this study is to see how the concept of slope is presented in mathematics textbooks of middle school. For this study, we analyzed the types of slope concepts in the textbooks. In particular, we analyzed motivation activity, definition, examples of slope in them and used a concept framework of slope by Stump(1999, 2001), Moore-Russo, Connor & Rugg (2011). As a result, it was shown that middle school mathematics textbooks use the types of slope concepts to be biased when explaining the slope or presenting the slope problems. In addition, the real contexts of slope is poorly presented, and the concept types change from visual aspect to analytical aspect in the processes. This study provides suggestions on how to present the slope concepts in mathematics curriculum and middle school textbooks.