• Title/Summary/Keyword: slope area

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Ecological Diagnosis on Mt. nam in Seoul, Korea (남산의 생태학적 진단)

  • 이창석;문정숙;김재은;조현제;이남주
    • The Korean Journal of Ecology
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    • v.21 no.5_3
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    • pp.713-721
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    • 1998
  • The effects of artificial interference on the vegetation landscape in Mt. Nam of Seoul, Korea were clarified by analysing the distribution of vegetation landscape element and the number and size of patch depicted as a vegetation map in terms of landscape ecological principles. The effects of artificial interference on vegetation were also confirmed from the environmental gradient analysis on plant community extended from the lowland to the peak of that mountain. Vegetation landscape elements were divided into plantation and secondary forest in actual vegtation map. The ratio of plantation to secondary forest was higher in the lowland below mid-slope and the southern slope. Most afforested land were occupied by Robinia pseudoacacia and Populus tomentoglandulosa, Pinus rigida, P. koraiensis, Metasequoia glyptostroboides, Alnus hirsuta and so on are localy planted. In addition, projects to replace those afforested trees by P. densiflora as a kind of campaign for "Restoration of the one original feature of Mt. Nam" or to replace those tree species by planting young Abies holophylla or P. koraiensis under the mature afforested trees are also carried out in recent years. In cases of secondary forest, the southern slope was dominated by P. densiflora and the northern one by Q. mongolica. But the lowland of the northern slope is dominated by P. densiflora as the same as that in the southern slope. Vegetation landscape elements in Mt. Nam were much simplified comparing with that of suburban area around Seoul. The number of patches, which reflects the degree of diverse artificial interference was more in the lower area than in the upper area and more in the southern slope than in the northern one. On the other hand, the size of patch showed the antagonistic tendency to that of the number of patch. As a result of environmental gradient analysis, vegetation distribution in Mt. Nam was different from that in suburban area around Seoul. For example, Alnus japonica community, Zelkova serrata community, and Carpinus laxiflora community, which is established in mountain comparatively rare in artificial interference disappeared in Mt. Nam. As a result of analysis on vegetational succession in P. densiflora community and Q. mongolica community, both communities showed a tendency of retrogressive succession differently from that in control site located in suburban area around Seoul. In addition, species composition of P. densiflora and Q. mongolica communities in Mt. Nam were also different from those in Mt. Surak located around Seoul. It was interpreted that those results were originated from the environmental pollution and excessive arti ficial interferences.rferences.

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The Technique of Landslide Hazard Prediction Using Vegetation Interpretation of Aerial Photo (항공사진의 식생 판독에 의한 재해 예측 기법)

  • 강인준;곽재하;정재형
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.11 no.1
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    • pp.29-35
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    • 1993
  • The vegetation such as grass, shrub, tree has been used to control the erosion and stabilize the slope for a long time. But the effects of vegetation on slope area is usually neglected in traditional stability analyses. There are many errors in slope analyses in thin soil mantles. Therefore the effects of vegetation is an important factor. But it is difficult and complex to represent the vegetation influence quantitatively in stability analysis. In this study, authors choose the landslide region at the Kum sung dong Kum-jung ku Pusan as a model area. Authors analyzed the degree of slope with the aerial photo interpretation and DTM data extracted from the topographic map, and the relationship of D.B.H. (diameter of breast height), height, and age of tree in field investigation data. Finally authors know the fact that landslide take place approximately 10 or 20 years later in arbitrary afforestable area where the degree of slope is 27. The prevention effect must be considered in the control of vegetation.

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The Distribution and Geomorphic Change of Debris Slope at Ongjeom-ri in Cheongsong-gun (청송군 옹점리 일대 암설 사면의 분포와 지형 변화)

  • Lee, Gwang-Ryul;Park, Han-San
    • Journal of the Korean Geographical Society
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    • v.45 no.3
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    • pp.360-374
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    • 2010
  • The distributions, factors, and vegetation covers of debris slopes and changes of debris at the eastern Ongjeom-ri, Cheongsong-gun are analyzed. The important factors influencing on the developments of the slopes are felsites having advantages to the developments of cliffs and supply of enough debris, and the relatively long days below zero temperatures promoting the physical weathering processes. The distributional areas of the slopes at southern and western slopes are more extensive than those of northern and eastern slopes due to the active water evaporation by high insolation. The Ga area at eastern Ongjeom-ri has experienced the steady decreases of area of the slopes due to the vegetation covers and shows the increasing rates of vegetation covers of $431.0m^2/yr$ as averaged values. However, it is estimated at the Na area using terrestrial LIDAR that 1 or 2 debris were moved or displaed per year in slope.

Comparative Analysis of Terrain Slope Using Digital Map, LiDAR Data (수치지형도와 LiDAR 데이터를 이용한 지형경사도 비교분석)

  • Kang, Joon-Mook;Yoon, Hee-Cheon;Min, Kwan-Sik;Rhee, Won-Yong
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.4
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    • pp.3-9
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    • 2007
  • Recently, the efforts of systematic understanding and utilization of geographic phenomenon for human life as a important factor among activity of mankind are increasing. It is necessary to express topography connected with space. Especially, the technology of geographic analysis using DEM can supply the information rapidly and accurately about elevation and terrain slope of the subject area under the necessity of high 3D quality geographic information. In this study, creating more precise DEM derived from LiDAR data, quantitative analysis on the subject area about elevation and terrain slope is done under comparison with Digital Topographic map Scale 1:1000. LiDAR data is more detailed than Digital Topographic map to express the elevation of the subject area ($39.89{\sim}77.48m$), and terrain slope by analysis using DEM derived from LiDAR data come out minutely about 90%. It can be concluded that the LiDAR data is very applicable and accurate for 3D topographic terrain slope analysis.

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Analysis of Influence Factors of Forest Soil Sediment Disaster Using Aerial Photographs - Case Study of Pyeongchang-county in Gangwon-province - (항공사진을 이용한 산지토사재해 영향인자 분석 - 강원도 평창군을 중심으로 -)

  • Woo, Choong-Shik;Youn, Ho-Joong;Lee, Chang-Woo;Jeong, Yongho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.1
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    • pp.14-22
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    • 2008
  • The forest soil sediment disasters occurred in Jinbu-myeon Pyeongchang county were investigated characteristics by the aerial photograph analysis. After digitizing from aerial photographs, forest soil sediment disaster sites were classified into 695 collapsed sites, 305 flowed sites and 199 sediment sites. DEM (Digital Elevation Model) were generated from 1 : 5,000 digital topographic map. Factors of geography, hydrology, biology, and geology were analyzed using DEM, geologic map, and forest stand map with aerial photographs by GIS spatial analysis technique. The forest soil sediment disasters were mainly occurred from southeastern slope to southwestern slope. In collapsed sit es, the average slope degree is $28.9^{\circ}$, the average flow length is 163.5m, the average area of drainage basin is 897$m^2$. In case of flowed sites, the average slope degree, flow length, the area of drainage basin and confluence order is $27.0^{\circ}$, 175m, 2,500$m^2$ and 1, respectively. In sediment sites, the average slope, flow length, the area of drainage basin and confluence order is $12.5^{\circ}$, 2,50m, 25,000$m^2$ and 4, respectively. Also the forest soil sediment disasters were occurred most of collapsed sites in the afforest land after felling and igneous rocks composed of granite.

Characterization of the Distribution of Indicator Species Beetles in the Mt. Mangunsan Area

  • Junsu Kim;Man-Leung Ha;Hyun Kim;Chong Kyu Lee
    • Journal of Forest and Environmental Science
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    • v.40 no.2
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    • pp.82-89
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    • 2024
  • This study aimed to investigate habitat distribution and beetle diversity, using beetles as biological indicator species to assess environmental changes in the Mt. Mangunsan area near the South Sea of Korea. Plots were installed at varying elevations on the southern and northern slopes of Mt. Mangunsan, and the beetle species composition was determined. A total of 1,368 beetles comprising 32 species belonging to ten families were collected between May and September 2023 from the study sites in the Mt. Mangunsan area near the South Sea of Korea. The two most prevalent species consisted of Synuchus nitidus, with 152 collected beetles, and Calosoma chinense, with 128 collected beetles. In May, June, July, August, and September, 76 beetles comprising 10 species, 180 beetles comprising 18 species, 138 beetles comprising 15 species, 525 beetles comprising 27 species, and 449 beetles comprising 25 species were collected, respectively, with the highest abundance observed in August. In terms of elevation, 239 beetles comprising 19 species were collected at 300 m; 352 beetles comprising 27 species at 400 m; 314 beetles comprising 24 species at 500 m; 280 beetles comprising 22 species at 600 m; 183 beetles comprising 16 species at 700 m. Based on the slope, 442 beetles comprising 18 species belonging to eight families were collected on the southern slope, and 926 beetles comprising 24 species belonging to 10 families were collected on the northern slope. Analysis of the beetles on the southern slope produced the following estimations: diversity of 1.086, evenness of 0.866, and dominance of 0.109. Meanwhile, those in the northern slope yielded a diversity of 1.204, evenness of 0.873, and dominance of 0.081.

The Analysis of Terrain and Topography using Fractal (프랙탈 기법에 의한 지형의 특성분석)

  • Kwon, Kee-Wook;Jee, Hyung-Kyu;Lee, Jong-Dal
    • Journal of the Korean association of regional geographers
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    • v.11 no.6
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    • pp.530-542
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    • 2005
  • In this study, GIS method has been used to get fractal characteristics. Using the projected area and surface area, 2 dimensional fractal characteristic of terrain was found out. Correlation of fractal dimension and mean slope were also checked over. Results are as below. 1) To get a fractal dimension, the method which is using the surface area is also directly proportional to complexity of the terrain as other fractal dimension. 2) Fractal dimensions using the surface area, that is proposed in this thesis are carried out as below : Uiseong : $2.02{\sim}2.15$ Yeongcheon : $2.10{\sim}2.24$. These values are in a range of fractal $2.10{\sim}2.20$ dimensions which has known. 3) Correlation of mean slope and fractal dimension is diminished about 30% in a region which is more than $25^{\circ}$ of mean slope. So, in this region using the fractal dimension method is better than using the mean slope. From this study, on formula using the projected area and surface area is still good to get a fractal dimension that has been found. But to confirm this method the region of research should be wider and be set up the correlation of mean slope, surface area and fractal dimension. It can be applicable to restoration of terrain and traffic flow analysis in the future research.

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UAV Aerial Photogrammetry for Cross Sectional Extraction and Slope Stability Analysis in Forest Area (UAV 항공사진을 이용한 산림지 횡단면도 추출 및 사면안정성 평가)

  • Kim, Taejin;Son, Younghwan;Park, Jaesung;Kim, Donggeun
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.1
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    • pp.67-77
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    • 2018
  • The objective of this study is to extract the shape of the slope from the images acquired using UAV and evaluate its suitability and reliability when applied to slope stability analysis. UAV is relatively inexpensive and simple, and it is possible to make terrain survey by generating point clouds. However, the image acquired from UAV can not be directly photographed by the forest canopy due to the influence of trees, resulting in severe distortion of the terrain. In this study, therefore, the effects of forest canopy were verified and the slope stability analysis was performed. Images acquired in winter and summer were used, because summer images are heavily influenced by the forest canopy and winter images are not. As a result of the study, the winter image is suitable for the extraction of slope shape, but severe terrain distortion occurs in the summer image. Therefore, slope stability analysis using slope shape extracted from summer image is impossible, so it should be modified for slope stability analysis. The modified slope did not completely eliminate the distortion of the terrain, but it could express the approximate shape of the slope. As a result of the slope stability analysis, the location and shape of the failure surface are the same, and the error of the safety factor is less than 0.2, which is close to the actual slope.

A Case Study on the Prediction for Disaster Prevention of Unstable Slope (불안정사면의 재해방지 예측 사례연구)

  • 정철호;심정경
    • Proceedings of the Korean Geotechical Society Conference
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    • 1994.06c
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    • pp.75-93
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    • 1994
  • This paper reviewed safety on unstable slope of site development area in Pusan, and analyzed deformation behavior characteristics cf the slope according to the correlation with the iesultsoffteldmeasurementanddailyrainfalls. The method of the predicticul for disaster Fevention was established as being verified by means of numerical analysis as results.

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A Geologic Disasters in Quaternary Volcanic Area, Ulreung-Island (제사기(第四紀) 화산암(火山岩) 분포지역(分布地域)에 빈발(頻發)하는 지질재해(地質災害)에 관(關)하여)

  • Kim, Young Ki
    • Economic and Environmental Geology
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    • v.13 no.2
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    • pp.80-90
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    • 1980
  • A geologic disasters in Ulreung-island is forming along the slope of pyroclastic, deposits and this paper discusses soil mechanics and properties and morphologies of pyroclastic soil. The typers of degradation are determined by cutting the soil and classified genetically. Finally, the range of stability is deduced from dip of slope (${\alpha}$) and lengh of slope (l) as the following;.

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