• Title/Summary/Keyword: aspect and slope analysis

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Analysis of Landslide Factors Using Geo-Spatial Information System and Analytic Hierarchy Process (GSIS와 AHP법을 이용한 산사태 유발인자 분석)

  • 양인태;김제천;천기선;김동문
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.3
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    • pp.273-281
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    • 2001
  • The landslide occurrence in Sam-Chuck area was analyzed through Geo-Spatial Information System and AHP(Analytic Hierarchy Process). Among many factors which causes landslide, terrain slope, terrain aspect, lithology, soil texture and vegetation arc taken as input data from existing maps and constructed as a database. These factors are determined by each environmental factor by environmental and geological characters in the study area, and the rating and weight about factor are input using AHP. Possible areas for landslide have been extracted by overlaying each layers. Finally, the estimated results are compared with real landslide sites to know which factor is the most effective for landslide. The results showed that lithology and soil factor have high susceptibility in Sam-Chuck area.

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GIS-based Landslide Susceptibility Mapping of Bhotang, Nepal using Frequency Ratio and Statistical Index Methods

  • Acharya, Tri Dev;Yang, In Tae;Lee, Dong Ha
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.5
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    • pp.357-364
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    • 2017
  • The purpose of the study is to develop and validate landslide susceptibility map of Bhotang village development committee, Nepal using FR (Frequency Ration) and SI (Statistical Index) methods. For the purpose, firstly, a landslide inventory map was constructed based on mainly high resolution satellite images available in Google Earth Pro, and rest fieldwork as verification. Secondly, ten conditioning factors of landslide occurrence, namely: altitude, slope, aspect, mean topographic wetness index, landcover, normalized difference vegetation index, dominant soil, distance to river, distance to lineaments and rainfall, were derived and used for the development of landslide susceptibility map in GIS (Geographic Information System) environment. The landslide inventory of total 116 landslides was divided randomly such that 70% were used for training and remaining 30% for validating result by receiver operating characteristics curve analysis. The area under the curve were found to be greater than 0.7 indicating an acceptable susceptibility maps obtained using FR and SI methods in GIS for hilly region of Nepal.

Landslide Susceptibility Analysis in Baekdu Mountain Area Using ANN and AHP Method

  • Quan, Hechun;Moon, Hongduk;Jin, Guangri;Park, Sungsik
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.12
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    • pp.79-85
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    • 2014
  • To analyze the landslide susceptibility in Baekdu mountain area in china, we get two susceptibility maps using AcrView software through weighted overlay GIS (Geographic Information System) method in this paper. To assess the landslide susceptibility, five factors which affect the landslide occurrence were selected as: slope, aspect, soil type, geological type, and land use. The weight value and rating value of each factor were calculated by the two different methods of AHP (Analytic Hierarchy Process) and ANN (Artificial Neural Network). Then, the weight and rating value was used to obtain the susceptibility maps. Finally, the susceptibility map shows that the very dangerous areas (0.9 or higher) were mainly distributed in the mountainous areas around JiAnShi, LinJiangShi, and HeLongShi near the china-north Korea border and in the mountainous area between the WangQingXian and AnTuXian. From the contrast two susceptibility map, we also Knew that The accuracy of landslide susceptibility map drew by ANN method was better than AHP method.

Development of Macro-Element for the Analysis of Elastically Supported Plates (탄성 지지된 판구조 해석을 위한 매크로 요소의 개발)

  • 강영종;박남회;앙기재;최진유
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.1
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    • pp.25-35
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    • 2000
  • The superstructure of general bridge like slab bridge and slab on girder bridge is composed of elastically supported isotropic plate. The objective of this study is to develop the new analysis method for elastically supported plate with general edge beam or girder(boundaries) under arbitrary out of plane loading. The displacement solutions for the macro-element of plate and beam are obtained by solving for the unknown interactive forces and moments at the beam or nodal line locations after satisfying equilibrium equation along the nodal line. The displacement functions for macro-elements ate proposed in single Fourier series using harmonic analysis, and the equilibrium equations of nodal line are composed by using slope-deflection method. The proposed analysis method is programmed by MS-Fortran and can be applied to all types of isotropic decks with bridge-type boundaries. Numerical examples involving elastically supported plates with various aspect ratio, loading cases, and bridge-type boundary conditions are presented to demonstrate the accuracy of this program. The major advantage of this new analysis method is the development of a simple solution algorithm, leads to obtain rapidly responses of bridge deck system. This proposed method can be used in parametric study of behavior of bridge decks.

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Physical Properties of Soils in Relation to Forest Composition in Moist Temperate Valley Slopes of the Central Western Himalaya

  • Sharma, C.M.;Gairola, Sumeet;Ghildiyal, S.K.;Suyal, Sarvesh
    • Journal of Forest and Environmental Science
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    • v.26 no.2
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    • pp.117-129
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    • 2010
  • The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to assess the physical properties of soils in relation to the forest structure and composition. Twelve forest types according to the altitude, slope aspect and species compositions were selected for the study. Physical properties of soil i.e., soil colour, soil texture (per cent of sand, silt and clay), moisture content, water holding capacity, porosity, bulk density (gm/$cm^3$) and void ratio were analyzed for three different depths viz., (i) 'upper' (0-10 cm), (ii) 'middle' (11-30 cm) and (iii) 'lower' (31-60 cm) in all the selected forest types. Phytosociological and diversity parameters viz. total basal cover ($Gha^{-1}$), stem density ($Nha^{-1}$), tree species richness, Simpson concentration of dominance and Shannon-Wiener diversity index were also calculated for each forest type. This study also provides the comparisons between the results of physical analysis of the present study with numerous other previous studies in the temperate Himalayan region of the Uttarakhand.

Investigation Plant Species Diversity and Physiographical Factors in Mountain Forest in North of Iran

  • Hashemi, Seyed Armin
    • Journal of Forest and Environmental Science
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    • v.26 no.1
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    • pp.1-7
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    • 2010
  • Species diversity is one of the most important specifications of biological societies. Diversity of organisms, measurement of variety and examination of those hypotheses that are about reasons of diversity are such as affairs that have been desired by the ecologists for a long time. In this research, diversity of plant species in forest region, numbers of 60 sample plots in 256.00 square meters have been considered in random - systematic inventory was considered. In each sample plot, four micro-plots in 2.25 square meters in order to study on herbal cover, were executed that totally 240 micro-plots were considered. At each plot six diversity indices in relation to physiographic factors (slope, geographical aspect and altitude from the sea level) were studied. The results indicate that species diversity is more in the northern direction and also species diversity in slops less than 30% has the most amounts. Factor of altitude from the sea level did not have meaningful relation with species diversity. Through study on correlation of the numbers of species in sample plots with indices and also process and role of indices in different processors of analysis, Simpson's reciprocal index was suggested as suitable index in this type of studies.

Development of Habitat Suitability Analysis Models for Wild Boar(Sus Scrofa) : A Case Study of Mt. Sulak and Mt. Jumbong (멧돼지 서식지 적합성 분석 모형 개발 -점봉산, 설악산 지역을 대상으로-)

  • 김원주;박종화;김원명
    • Spatial Information Research
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    • v.6 no.2
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    • pp.247-256
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    • 1998
  • The objective of this research was to develop habitat suitability models for wild boar (Sus Scrafa) in Mt. Sulak National Park and Mt. Jumbong Natural Forest Reserve. The study area is covered-with climax temperate hardwood forests ot'mainly Mongolian oak ($\textit{Quercus mongolica}$), and has diverse wildlife species including wild boars. Three suitability models - summer, fall, and annual models - were developed. These models were based on slope, aspect, forest types, forest year classes, distance from streams and trails. Habitat data collected through telemetry were used for the models. The accuracy of the models was tested by comparing observed traces of wild boar in Mt. Jurnbong, and most traces were on suitable areas on the suitability maps.

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Forest Structure in Relation to Slope Aspect and Altitude in Valley Forests at Kyeryongsan National Park (계룡산국립공원 계곡부의 사면방향과 해발고에 따른 산림구조)

  • 박인협;서영권
    • Korean Journal of Environment and Ecology
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    • v.14 no.4
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    • pp.296-302
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    • 2001
  • 계룡산국립공원 연천봉고개(해발 700m)를 중심으로 남향사면인 시원사~원천봉고개와 북향사면인 갑사~연천봉고개를 대상으로 사면방향과 해발고에 따른 교목층과 아교목층의 산림구조를 조사분석하였다. 남향사면은 북향사면에 비하여 교목측의 밀도는 높은 반면 평균흉고직경은 작았다. 특수한 지형인 주능선부에 위치하는 정부를 제외하며, 해발고가 높아짐에 따라 교목층과 아교목층 전체의 평균흉고직경과 흉고단면적인 남향사면에서는 감소하는 경향을 보였다. 북향사면은 남향사면에 비하여 교목층과 아교목층 전체의 동다양도와 균재고가 높았다. 남향사면에서 해발고가 높아짐에 따라 중요치가 증가하는 수종은 느티나무, 졸참나무, 까지박달, 신갈나무등이었으며, 중요치가 감소하는 수종은 굴참나무, 서어나무, 때죽나무 등이었다. 북향사면의 경우 해발고가 높아짐에 따라 중요치가 증가하는 수종은 까치박달, 쪽동백나무 등이며, 중요치가 감소하는 수종은 때죽나무, 졸참나무 등이었다. Cluster 분석결과 남향사면중, 하부의 굴참나무-낙엽활엽수군집지, 남향사면 상부와 북향사면상, 중의 신갈나무-낙엽활엽수군집, 북향사면 하부와 정부의 신갈나무-소나무군집 등 3개 군집으로 구분되었다. 굴참나무, 산벚나무, 밤나무 등 3개 수종간에는 유의적인 정의 상관이 있었으며, 유의적인 정의 상관을 보인 굴참나무, 산벚나무, 밤나무 등 3개 수종은 당당풍과 유의적인 부의 상관이 있었다.

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Forest Structure in Relation to Slope Aspect and Altitude in Valley FOrests at Chirisan National Park (지리산국립공원 계곡부의 사면방향과 해발고에 따른 산림구조)

  • 박인협;임도형;문광선
    • Korean Journal of Environment and Ecology
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    • v.14 no.1
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    • pp.11-17
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    • 2000
  • 지리산국립공원의 장터목을 중심으로 남향사면인 중산리-장터목지역과 북향사면인 가내소폭포-장터목지역을 대상으로 사면방향과 해발고에 따른 교목츠의 산림구조를 조사분석하였다 북향사면은 남향사면에 비하여 교목층의 밀도 흉고단면적 종다양도가 높은경향을 보였다 특수한 지형인 주능선부에 위치하는 정부를 제외하면 해발고가 ?아짐에 따라 교목층 전체의 평균 흉고직경과 흉고단면적은 북혀 사면에서는 감소하는 반면 남향사면에서는 증가하는 경향을 보였다 종수, 종다양도, 균재도는 남향사면과 북향사면 모두 해발고가 높아짐에 따라 감소하였다 남향사면과 북향사면에서 모두 해발고가 증가함에 따락 중요치가 높아지는 수종은 구상나무 철쭉꽃 등이었으며 중요치가 감소하는 수종은 졸참나무 서어나무 생강나무 등이었다 cluster 분석결과 남향사면 하부의 졸참나무-활엽수군집 남향사면 중부와 북향사면 하부의신갈나무-전나무군집 남향사면 상부와 북향사면 상중부의 구상나무-활엽수군집 정부의 구상나무군집 등 4개 유형의 군집으로 구분되었다. 졸참나무 산뽕나무 비목나무 고로쇠나무 서어나무 다릅나무 등의 수종간에는 유의적인 정의 상관이 있어으며 구상나무와 사닥나무는 노각나무와 유의적인 부의 상관이 있었다.

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GIS Application for Site Planning

  • Han, Seung-Hee;Lee, Jin-Duk
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.1
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    • pp.53-59
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    • 2009
  • The general urban plan is the plane plan which limits general and uniformed constructions; however, the district unit plan is the solid plan that can leads various constructions by discriminating by plot, housing area and lot. Therefore, for the zone plan, not only the two-dimensional plot information such as plot usage plan, but also the three-dimensional plot information needs to be used to analyze lighting, sewerage and directions. To fulfill such requirements, the information can be gathered using GIS and photogrammetric method for the reasonable and efficient zone plan. In this research, the information about the testing area for the zone plan has been gathered using GIS method, and the three-dimensional model about the area has been built using the satellite image and DEM. As the result, plot usage analysis, direction analyst, water system analysis, and slope analysis has been done and used efficiently to build the district unit plan. Also, after the result after applying the analyzed result to the actual area says this is very appropriate and efficient.

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