• Title/Summary/Keyword: GIS spatial analysis

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Analysis of Rock Slope Stability by Using GIS in Mt. Keumsu Area (지구정보시스템을 이용한 금수산일대의 암반사면 안정성 평가)

  • 배현철
    • Economic and Environmental Geology
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    • v.33 no.1
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    • pp.77-88
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    • 2000
  • The goal of this study is to assess the spatial distribution of natural slopes and cutting slopes under would-be development. For this goal, a quantitative slope stability analysis method using GIS integrated with a computer program was developed. Through field investigations, the discontinuity parameters were collected such as orientation of discontinuity, persistence, spacing, JRC, JCS, and water depth. The distributions were interpolated from the ordinary kriging method in ARC/INFO GIS after variogram analysis. The layers showing all parameters needed for limit equilibrium analysis were constructed. The final layer using GIS works composed of 162,352 polygons, that is, unit slopes. The rock slope stability analysis program was coded by C++ language. This program can calculate geometrical vectors related to rock block failures using input orientation data and direction and dimension of strength to occur failure. Also, this can calculate shear strength of joints through empirical equations and quantitative factors of safety. This methodology was applied to the study area which is located in Jaecheon city and Danyang-gun of the northeastern Keumsu is about 135$km^2$. As a result, the study area was entirely stable but unstable, that is, factor of safety less than 1.0dominantly at the slopes near Keumsil, Daejangri, Keumsungmyun and Sojugol, Mt. Dongsan, Juksongmyun by the natural slope stability analysis. Assuming the cutting slope showing the same direction immediate, and quantitative analysis of factors of safety for a regional area could be conducted through GIS integrated with a computer program of limit equilibrium.

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Neighborhood Correlation Image Analysis for Change Detection Using Different Spatial Resolution Imagery

  • Im, Jung-Ho
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.337-350
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    • 2006
  • The characteristics of neighborhood correlation images for change detection were explored at different spatial resolution scales. Bi-temporal QuickBird datasets of Las Vegas, NV were used for the high spatial resolution image analysis, while bi-temporal Landsat $TM/ETM^{+}$ datasets of Suwon, South Korea were used for the mid spatial resolution analysis. The neighborhood correlation images consisting of three variables (correlation, slope, and intercept) were evaluated and compared between the two scales for change detection. The neighborhood correlation images created using the Landsat datasets resulted in somewhat different patterns from those using the QuickBird high spatial resolution imagery due to several reasons such as the impact of mixed pixels. Then, automated binary change detection was also performed using the single and multiple neighborhood correlation image variables for both spatial resolution image scales.

Development of Pre-Environmental Investigation GIS Decision Making System Using Spatial Analysis Technique (공간분석기술을 활용한 사전환경성 검토 GIS 의사결정시스템 개발)

  • Kim, Sang Seok;Jang, Yong Gu;Kang, In Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1D
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    • pp.185-193
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    • 2006
  • The on-going pre-environmental investigation at present is performed by separate numerical analysis of each provision which makes integrated pre-environmental investigation is difficult. The application of numerical data is insufficient, which results to the deterioration of environmental investigation result's objectivity. A lot of time and money is required for the investigation. In this study, the spacial analysis function of GIS was applied on the 8 pre-environmental investigation factors. Pre-environmental investigation GIS DMS(Decision Making System) was constructed to make integrated investigation possible through the use of investigation results for each factor. Through the use of the developed pre-environmental investigation GIS DMS and the pre-constructed GIS data, the objectivity of environmental investigation is sufficient and time and cost are reduced. Therefore, this system can be used for pre-environmental investigation during route selection in the initial stages of road construction. Through the numerical and visual data obtained from the system developed in this paper, it is easier to gain the approval of the public. Furthermore, environmental problems due to road construction can be investigated with less time and money during the initial stages of road construction.

Bird-Days Carrying Capacity Estimation of the Curlews Stopping Over in the Southern Intertidal Zone of Kanghwa Island (강화도 남단 조간대에 도래하는 마도요류의 환경수용능력 예측)

  • Moon, Young-Min;Kim, Kwan-Mok;Yoo, Jeong-Chil
    • Journal of Wetlands Research
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    • v.15 no.2
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    • pp.281-288
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    • 2013
  • In this study we estimated the carrying capacity of the southern intertidal zone of Kanghwa Island to evaluate the habitat quality for Curlews(Far Eastern Curlew Numenius madagascariensis and Eurasian Curlew Numenius arquata). Biomass of the macroinvertebrate(Macrophthalmus japonicus) was estimated by based on the spatial distribution of the sediment grain size using GIS tools. According to our analysis the southern intertidal zone of Kanghwa Island was able to support 11,767 individuals for 153 days in the Spring 2012 and 16,275 individuals for 122 days in the Autumn 2012. The proportion of mean population to the carrying capacity in the Spring and Autumn was 9.4% and 5.9%, respectively. These values are 2.8-6.3% smaller than those of the previous study held in 1993-94. For the conservation of the study area, more research and management is needed. And in further studies, diverse characteristics of the intertidal habitat should be considered in spatial analysis to have a precise estimate of the carrying capacity.

A Study on Estimates to Longevity Population of Small Area and Distribution Patterns using Vector based Dasymetric Mapping Method (벡터기반 대시매트릭 기법을 이용한 소지역 장수인구 추정 및 분포패턴에 관한 연구)

  • Choi, Don-Jeong;Kim, Young-Seup;Suh, Yong-Cheol
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.5
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    • pp.479-485
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    • 2011
  • A number of case studies that find distribution of longevity population and influencing factors through the spatial data fusion using GIS techniques are growing. The majority cases of these studies are adopt census administrative boundary data for the spatial analysis. However, these methods cannot fully explain the phenomenon of longevity because there are a variety of spatial characteristics within the census administrative boundaries. Therefore, studies of spatial unit are required that realistically reflect the phenomenon of human longevity. The dasymetric mapping method enables to product of spatial unit more realistic than census administrative boundary map and statistic estimates of small area utilizing diversity spatial information. In this study, elderly population of small area has been estimated within statistically significant level that applied the vector based dasymetric mapping method. Also, the cluster analysis confirmed that the variation of local spatial relationship within census administrative boundary. The result of this study implied that the need for local-level studies of the human longevity and the validity of the dashmetric mapping techniques.

Distribution Pattern of Pinus densiflora and Quercus Spp. Stand in Korea Using Spatial Statistics and GIS (공간통계와 GIS를 이용한 소나무림과 참나무류림의 분포패턴)

  • Lee, Chong-Soo;Lee, Woo-Kyun;Yoon, Jeong-Ho;Song, Chul-Chul
    • Journal of Korean Society of Forest Science
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    • v.95 no.6
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    • pp.663-671
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    • 2006
  • This study was performed for exploring the spatial distribution pattern of Pinus densiflora and Quercus spp. in Korea. Firstly, the spatial distribution map of Pinus densiflora and Quercus spp. was prepared in grid of $100m{\times}100m$ at national level, using digital forest type map and actual vegetation map. And thematic maps for topography, climate, and soil were also prepared in the raster form of $100m{\times}100m$. Through GIS based spatial analysis of the digital distribution map of Pinus densiflora and Quercus spp. and thematic maps, the spatial characteristics of Pinus densiflora and Quercus spp. distribution was explored in relation to the environmental factors such as topography, climate, and soil. And the occurrence frequency models of Pinus densiflora and Quercus spp. were derived. Pinus densiflora occurs more often than Quercus spp. at low elevation, low slope gradient, and high temperature areas. In addition, Pinus densiflora is mainly distributed at shallow and well-drained loamy soil from igneous rocks. In contrast, Quercus spp. is more common at shallow and well-drained loamy soil from metamorphic rocks. As a result, the prediction model for the spatial distribution of Pinus densiflora and Quercus spp. by topographical variables has proven successful with high statistical significance. The result of this study can contribute to rational management of Pinus densiflora and Quercus spp. stand in Korea, considering environmental factors such as topography, climate, and soil.

Studies on the Spatial Analysis for Distribution Estimation of Radon Concentration at the Seoul Area (서울지역 라돈농도의 분포예측을 위한 공간분석법 연구)

  • Baek, Seung-A;Lee, Tae-Jung;Kim, Shin-Do;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.5
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    • pp.538-550
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    • 2008
  • Radon is an invisible, odorless, and radioactive gas. It is formed by the disintegration of radium, which is a decay product of uranium. Some amounts of radon gas and its products are present ubiquitously in the soil, water, and air. Particularly high radon levels occur in regions of high uranium content. Although radon is permeable into indoor environment not only through geological features (bed rock and permeability) but also through the construction materials and underground water, the radiation from the geological features is generally main exposure factor. So there can be a problem in a certain space such as the underground and/or relatively poor ventilation condition. In this study, a GIS technique was used in order to investigate spatial distribution of radon measured from sub- way stations of 1 thru 8 in Seoul, Korea in 1991, 1998, 2001, and 2006. Spatial analysis was applied to reproduce the radon distribution. We utilized spatial analysis techniques such as inverse distance weighted averaging (IDW) and kriging techniques which are widely used to relate between different spatial points. To validate the results from the analyses, the jackknife technique for an uncertainty test was performed. When the number of measuring sites was less than 100 and also when the number of omitted sites increased, the kriging technique was better than IDW. On the other hand, when the number of sites was over 100, IDW technique was better than kriging technique. Thus the selection of analytical tool was affected sensitives by the analysis based on the number of measuring sites.

GIS for Subsidence Analysis by Considering Surface Condition (지표면의 조건을 고려한 지반침하 분석용 GIS)

  • 권광수;이준용;박형동
    • Economic and Environmental Geology
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    • v.34 no.6
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    • pp.595-600
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    • 2001
  • Recently, interests in subsidence hazard have been increased due to the underground construction such as subway construction and managements of abandoned mines. GIS analysis of subsidence hazard has a lot of advantages in handling of spatial data and managing database. For better result of GIS analysis, there are some necessities of modifying previous subsidence theory and model. To take surface profile into account allows the application of complicated topology. Furthermore. for 3-dimensional analysis. two subsidence profile curves that are perpendicular to each other should be considered simultaneously. Through these modifications, the model for subsidence analysis using GIS can be established. With ideal case of cavities and other conditions, GIS analysis was accomplished and meaningful results were produced. More realistic properties of cavity. soil layers, groundwater condition and topology will enable GIS analysis method to produce more reliable result and to widen the area of applications.

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A Study on the Satisfaction Analysis on Officially Assessed Land Price Using Time Seriate Geostatistical Analysis (시계열적 공간통계 기법을 활용한 공시지가의 만족도 분석에 관한 연구)

  • Choi, Byoung Gil;Na, Young Woo;Hyeon, Chang Seop;Cho, Tae In
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.2
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    • pp.95-104
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    • 2018
  • This study has the purpose of suggesting the method to analyze the spatiotemporal change of satisfaction concerning the officially assessed land price using geostatistical analysis. Analyzing the spatial distribution characteristic of officially assessed land price using present GIS (Geographic Information System) or is staying at qualitatively suggesting the improvement method of the officially assessed land price system. Grouping the appeal strength based on the official price and opinion price of officially assessed land price, GIS DB (Database) was constructed and the time seriate satisfaction were analyzed and compared through spatial density analysis and spatial autocorrelation analysis. As a result, it was found that the difference between the official price and the applicant's price differed depending on individual land, but most of the respondents requested the increase or the reduction of the average land price, which resulted in a large number of request. Analyzing the satisfaction of the officially assessed land price by using GIS, it was known that satisfaction of officially assessed land price could be analyzed by using the difference of the opinion price and not only the officially assessed land price. Spatiotemporal change of officially assessed land price satisfaction was known to be possible through spatiotemporal pattern analysis method such as spatiotemporal auto-corelation analysis and hotspot analysis etc using GIS. In short, regionally positive or negative significant relationship was investigated through spatiotemporal analysis using annual data.

Analysis on the Spatial Accessibility of Mental Health Institutions Using GIS in Gangwon-Do (GIS를 이용한 정신의료기관의 공간적 접근성 분석 - 강원도지역을 대상으로)

  • Park, Ju Hyun;Park, Young Yong;Lee, Kwang-Soo
    • Korea Journal of Hospital Management
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    • v.23 no.2
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    • pp.28-41
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    • 2018
  • Purpose: This study purposed to analyze the spatial accessibility of mental health institutions in Ganwon-Do using Geographic Information System and to suggest policy implications. Methodology: Network analysis was applied to assess the spatial accessibility of mental health institutions in Gangwon-Do. To perform the network analysis, network data set was built using administrative district map, road network, address of mental health institutions in Gangwon-Do. After building network data set, Two network analysis methods, 1) Service area analysis, 2) Origin Destination cost matrix were applied. Service area analysis calculated accessive areas that were within specified time. And using Origin Destination cost matrix, travel time and road travel distance were calculated between centroids of Eup, Myeon, Dong and the nearest mental health institutions. Result: After the service area analysis, it is estimated that 19.63% of the total areas in Gangwon-Do takes more than 60 minutes to get to clinic institutions. For hospital institutions, 23.08% of the total areas takes more than 60 minutes to get there. And 59.96% of Gangwon-do takes more than 30 minutes to get to general hospitals. The result of Origin-Destination cost matrix showed that most Eup Myeon Dong in Gangwon-Do was connected to the institutions in Wonju-si, Chuncheon-si, Gangneung-si. And it showed that there were large regional variation in time and distance to reach the institutions. Implication: Results showed that there were regional variations of spatial accessibility to the mental health institutions in Gangwon-Do. To solve this problem, Several policy interventions could be applied such as mental health resources allocation plan, telemedicine, providing more closely coordinated services between mental health institutions and community mental health centers to enhance the accessibility.