• Title/Summary/Keyword: Spatial Overlay Analysis

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The Error Analysis of Scale Effect for Dam Submerged Area and the Surrounded Regions (댐 수몰 및 주변지역의 축척 규모에 따른 오차분석)

  • Lee, Geun-Sang;Choi, Yun-Woong;Hwang, Eui-Ho;Chae, Young-Gang
    • Spatial Information Research
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    • v.18 no.4
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    • pp.43-53
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    • 2010
  • A dam is effective in stable supply of water required in daily life and reduction of damage from floods. hut a lot of land or houses arc submerged due to the construction of a darn heavily affecting environment in surrounding areas. In order to improve and support daily life environment. surrounding a dam, many projects have been conducted. and the study has focused on analyzing bow to calculate error characteristics of scale effect for submerged area by using GIS spatial overlay. First, as a result of areal error in submerged area by scale based on a 1/3,000 digital topographic map, it was found that the 1/5,000 digital topographic map is 9.5 times, 9.0 times and 10.5 times more accurate than the 1/25,000 digital topographic map, respectively, in the total of areal error, standard error and areal error for submerged area. Second, as a result of analysis on areal error in areas surrounding a dam, it has been found that Jinan-eup in Jinan-gun registered the largest difference in area within 2km and 2~5km catchment area by recording 13.8 times and 20.6 times, respectively, in the 1/5,000 digital topographic map compared to the 1/25,000 digital topographic map. In addition, in areas out of catchment area within 2km, the area of occupation was very small, so there were no characteristics in error. The out of catchment area, Nami-myeon in Geumsan-gun recorded the largest errors of 31.8 times. Finally, it was found that the ratio of the total areal error in area surrounding a dam, standard error and the total areal error in the entire area using 1,5000 digital topographic map is 7.4 times, 11.8 times and 7.4 times more accurate than the 1/25,000 digital topographic map.

Improving the Grading Indices for Land Suitability Assessment (토지적성평가 지표의 개선방안 연구 - 평가체계II를 중심으로 -)

  • Kim, In-Hyun;Oh, Kyu-Shik;Yang, Hee-Bum
    • Spatial Information Research
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    • v.17 no.2
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    • pp.201-212
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    • 2009
  • As GIS analysis method began to be introduced in late 1980's, studies of land development applying the GIS also started to be proceeded in various fields. Since 2003, Land Suitability Assesment has been adopted in order to prevent national land from development thoughtless for the environment and to plan appropriate national land management in terms of green development. Land Suitability Assessment System II based on diverse GIS analysis method such as Contour Analysis, Overlay Analysis, Network Analysis was particularly adopted to draft plans of specifying and altering of exclusionary zoning as well as installing and maintaining of urban planning facilities. But there has been a lot of problem, like an inaccurate basic data and assessment indicators, unmatched threshold, and contradicted evaluation result between each evaluating systems. Even though it is suited to an evaluation criteria, grade distribution is applied to start at 20, and development-centered evaluation result is offered. Now, we observed how suitability values and grading were changed, ordering to change grade distribution system from $20{\sim}100$ to $0{\sim}100$. In result, it showed changes of grades in some parcels. And in case of suitability values, 87% of parcels decreased to minimum 1 point, maximum 70 points. It means that changing grade distribution system of assessment system II doesn't have only influence on suitability values and grading but it is also an empirical analysis because of considering both development and maintenance.

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A Method to Measure Damage Areas by the types of Railroad Hazardous Material through GIS Spatial Analysis (GIS 공간 분석기법을 통한 철도사고위험물질별 피해규모 자동추출방안)

  • Kim, Sang-Gyun;Kim, Si-Gon;Lee, Won-Tea
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1769-1778
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    • 2009
  • Due to the industrialization and urbanization, the transport of hazardous materials increases, which rises possibilities in occurring prospective accidents in terms of hazardous material transport as well. This study applied the model developed from the previous research to analyze the scale of damage areas from the accidents related to hazardous material accidents, as well as suggested a method to measure automatically the scale of accident including casualties and environmental damage based on the guideline which suggests the quantities of hazardous materials exposed from an accident and was defined in the study of standardization for hazardous material classification. A buffering analysis technique of Geographic Information System (GIS) was applied for that. To apply the model which evaluates the scale of population and exposure to environment on each link, rail network, zones, rail accident data, rail freight trips, and locations of rivers etc were complied as a database for GIS analysis. In conclusion, a method to measure damage areas by the types of hazardous materials was introduced using a Clip and a Special Join technique for overlay analysis.

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Derivation of Candidate Sites for a Tidal Current-Pumped Storage Hybrid Power Plant Using GIS-based Site Selection Analysis (GIS기반 적지분석을 통한 조류-양수 융합발전시스템 설치후보지 도출 연구)

  • LEE, Cholyoung;CHOI, Hyun-Woo;PARK, Jinsoon;KIM, Jihoon;PARK, Junseok
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.4
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    • pp.184-207
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    • 2020
  • This study aimed to determine candidate areas for tidal current-pumped storage hybrid power plants using GIS-based site selection analysis. The study area is the southwestern sea surrounding Jindo Island in South Korea. Factors to be considered for the site selection analysis were derived considering the design and installation characteristics of the hybrid power plant. Numerical simulation to predict tidal speed was performed using the MOHID(Modelo HIDrodin?mico) and the results were converted into spatial data. Subsequently, a GIS-based overlay analysis method proposed in this study was applied to derive the installation candidate area. A total of 10 regions were identified as candidate sites. Among them, it was determined that the power generator could be installed in relatively wide sea areas in Jindo, Seongnamdo, and Hajodo.

Use of Geographical Information Systems in Analyzing Large Area Distribution and Dispersal of Rice Insects in South Korea (벼 해충의 분포와 분산의 해석에 있어서 지리정보처리체계의 활용)

  • ;K. L. Heong
    • Korean journal of applied entomology
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    • v.32 no.3
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    • pp.307-316
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    • 1993
  • The potential of using GIS in analyzing pest surveillance data was explored. The Spatial Analysis System (SPANS) was used to construct a spatial data base to study pest distributions using pest surveillance data collected from 152 stations in South Korea. The annual spatIal distributions of the striped rice borer(SRB), Chdo suppressalis, showed that high densities started to expand in the early 1980s, reaching a peak in 1988. The pattern change appears to be related to cultivation of japonica and indica-japonica hybrid varieties in South Korea. Japo7l!ca varieties have longer duration resulting in the SRB haVlng more time to mature and hibernate in wmter. The locus of SRB spread appears to be located in the mid-west region near lri, Chun~ Buk Province. High brown planthopper (BPH) populations in South Korea are often related to the early immigration and temperature. The simulated distribution of PPH densities in September using these two factors was compared with the actual distribution obtained using 1990 data. The two density maps corresponded closely excepL for differences in the south eastern valley. By overlaying the simulated map layer with the elevation and rice area maps, more specific BPH risk zones could be identified.

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An Empirical Study on Discrimination of Image Algorithm for Improving the Accuracy of Forest Type Classification -Case of Gyeongju Area Using KOMPSAT-MSC Image Data- (임상 분류 정확도 향상을 위한 영상 알고리즘 변별력 실증 연구 -KOMPSAT-MSC를 이용한 경주지역을 대상으로-)

  • Jo, Yun-Won;Kim, Sung-Jae;Jo, Myung-Hee
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.2
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    • pp.55-60
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    • 2009
  • By applying NDVI(Normalized Difference Vegetation Index) and TCT(Tasseled-Cap Transformation) image algorithm on the basis of KOMSAP-2 MSC(Multi Spectral Camera) image(Jun. 12, 2007) for Naenam-myeon, Gyeongju city in this study, DN distribution map was drawn up. Discrimination analysis of image algorithm for the accuracy improvement of forest type classification was conducted through the comparative analysis between the distribution maps of NDVI and TCT DN, and forest field surveying data, and finally, the accuracy of the forest type classification was verified through the overlay analysis with the forest field surveying data. Through this study, it is thought that low cost and high efficiency will be able to be expected in the process of the examination for the automation practicality of the forest type classification and of the production of the accurate forest type classification map by using KOMPSAT-2 MSC image.

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Weight Determination of Landslide Factors Using Artificial Neural Networks (인공신경 망을 이용한 산사태 발생요인의 가중치 결정)

  • 류주형;이사로;원중선
    • Economic and Environmental Geology
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    • v.35 no.1
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    • pp.67-74
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    • 2002
  • The purpose of this study is to determine the weights of the factors for landslide susceptibility analysis using artificial neural network. Landslide locations were identified from interpretation of aerial photographs, field survey data, and topography. The landslide-related factors such as topographic slope, topographic curvature, soil drainage, soil effective thickness, soil texture, wood age and wood diameter were extracted from the spatial database in study area, Yongin. Using these factors, the weights of neural networks were calculated by backpropagation training algorithm and were used to determine the weight of landslide factors. Therefore, by interpreting the weights after training, the weight of each landslide factor can be ranked based on its contribution to the classification. The highest weight is topographic slope that is 5.33 and topographic curvature and soil texture are 1 and 1.17, respectively. Weight determination using backprogpagation algorithms can be used for overlay analysis of GIS so the factor that have low weight can be excluded in future analysis to save computation time.

Linkage of GSIS and Expert System for Route Selection (노선선정을 위한 GSIS와 전문가체계의 연계)

  • 이형석;배상호;강준묵
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.2
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    • pp.137-146
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    • 2001
  • Route selection needs the analysis function of GSIS to analyze and manipulate a lot of spatial information efficiently. Therefore, it needs the linkage of system requiring the knowledge and the experience of experts as a method that can estimate each quantitative route for an efficient route selection. In this study, the route selection model through construction and analysis procedure of position information using GSIS were presented, and route selection system linked with expert system was developed. This system is easy to be used and managed for presenting route alignment according to conditions as a graphic user interface environmental window system by applying three tiers based object-oriented method. Using GSIS, the various information required for route selections in database was constructed, the characteristics of subject area by executing three-dimensional terrain analysis was grasped effectively, and the control point through buffering, overlay and location operation was extracted. Three alternative routes between a beginning point and an end point inputted by route selection system were selected. Therefore, the applications of the route selection system are presented by applying this system to the real study area.

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Analysis of Landslide in Inje Region Using Aerial Photograph and GIS (항공사진과 GIS를 이용한 인제지역 산사태 분석)

  • Son, Jung-Woo;Kim, Kyung-Tak;Lee, Chang-Hun;Choi, Chul-Uong
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.2
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    • pp.61-69
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    • 2009
  • In mid-July, 2006 the torrential rainfall across Gangwon-do region caused 48 casualties and 1,248 houses submerged, resulting in damages with the restoration costs of 3 trillion and 512.5 billion won. This was because the topographic characteristics of Gangwon-do region for which mountainous areas mostly account increased the effects of landslide. In this study, the landslide region was shot using the PKNU No.4 system immediately after the occurrence of landslide in order to analyze it as objectively, exactly, and rapidly as possible. 1,054 areas with landslide occurrence were extracted by digitizing the shot images through visual reading after orthometric correction using ERDAS 9.1. Using the Arc GIS 9.2, a GIS program, hydrologic, topographic, clinical, geologic, pedologic aspects and characteristics of the landslide region were established in database through overlay analysis of digital map, vegetation map, geologic map, and soil map, and the status and characteristics of the occurrence of the landslide were analyzed.

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Relationship Analysis between Lithology, Geological time and Geothermal Gradient of South Korea (남한지역의 암상 및 지질시대별 지온경사율 관계 분석)

  • 김형찬;이사로;송무영
    • Economic and Environmental Geology
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    • v.35 no.2
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    • pp.163-170
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    • 2002
  • The purpose of this study is to analyze the relationship between geology and geothermal gradient in South Korea using GIS. For the analysis, 352 temperature logging wells were constructed to spatial database and the relationships beween geothermal gradient and geological time and lithology were analyzed using the overlay the wells layer and 1:1,000,000 scale geological map layer. The average of the geothermal aradient of South Korea is 29.34$^{\circ}C$/km. In the geologic sequence, Cenozoic strata has 39.7$0^{\circ}C$/km, Mesozoic strata has 30.63$^{\circ}C$/km , Paleozoic strata has 22.32$^{\circ}C$/km, Proterozoic strata 23.15$^{\circ}C$/km geothermal gradient value. In the lithological aspect, plutonic rocks 33.96$^{\circ}C$/km, sedimentary rocks have 24.78$^{\circ}C$/km and sedimentary and volcanic rocks have 26.85$^{\circ}C$/km geotermal gradient value. The result can be used to develop geothermal energy and hot spring as a reference.