• Title/Summary/Keyword: Spatial Overlay Analysis

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The Application of RS and GIS Technologies on Landslide Information Extraction of ALOS Images in Yanbian Area, China

  • Quan, He Chun;Lee, Byung Gul
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.3
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    • pp.85-93
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    • 2015
  • This paper mainly introduces the methods of extracting landslide information using ALOS(Advanced Land Observing Satellite) images and GIS(Geographical Information System) technology. In this study, we classified images using three different methods which are the unsupervised the supervised and the PCA(Principal Components Analysis) for extracting landslide information based on characteristics of ALOS image. From the image classification results, we found out that the quality of classified image extracted with PCA supervised method was superior than the other images extracted with the other methods. But the accuracy of landslide information extracted from this image classification was still very low as the pixels were very similar between the landslide and safety regions. It means that it is really difficult to distinguish those areas with an image classification method alone because the values of pixels between the landslide and other areas were similar, particularly in a region where the landslide and other areas coexist. To solve this problem, we used the LSM(Landslide Susceptibility Map) created with ArcView software through weighted overlay GIS method in the areas. Finally, the developed LSM was applied to the image classification process using the ALOS images. The accuracy of the extracted landslide information was improved after adopting the PCA and LSM methods. Finally, we found that the landslide region in the study area can be calculated and the accuracy can also be improved with the LSM and PCA image classification methods using GIS tools.

A Study on Development of a GIS based Post-processing System of the EFDC Model for Supporting Water Quality Management (수질관리 지원을 위한 GIS기반의 EFDC 모델 후처리 시스템 개발 연구)

  • Lee, Geon Hwi;Kim, Kye Hyun;Park, Yong Gil;Lee, Sung Joo
    • Spatial Information Research
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    • v.22 no.4
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    • pp.39-47
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    • 2014
  • The Yeongsan river estuary has a serious water quality problem due to the water stagnation and it is imperative to predict the changes of water quality for mitigating water pollution. EFDC(Environmental Fluid Dynamics Code) model was mainly utilized to predict the changes of water quality for the estuary. The EFDC modeling normally accompanies the large volume of modeling output. For checking the spatial distribution of the modeling results, post-processing for converting of the output is prerequisite and mainly post-processing program is EFDC_Explorer. However, EFDC_Explorer only shows the spatial distribution of the time series and this doesn't support overlay function with other thematic maps. This means the impossible to the connection analysis with a various GIS data and high dimensional analysis. Therefore, this study aims to develop a post-processing system of a EFDC output to use them as GIS layers. For achieving this purpose, a editing module for main input files, and a module for converting binary format into an ASCII format, and a module for converting it into a layer format to use in a GIS based environment, and a module for visualizing the reconfigured model result efficiently were developed. Using the developed system, result file is possible to automatically convert the GIS based layer and it is possible to utilize for water quality management.

An Assessment of Coastal Area Using Geographic Information Systems and Multi-Criteria Analysis (지리정보시스템(GIS)과 다기준 분석법(MCA)을 적용한 연안지역 평가)

  • Choi, Hee-Jung;Park, Jung-Jae;Hwang, Chul-Sue
    • Journal of the Korean association of regional geographers
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    • v.13 no.2
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    • pp.143-155
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    • 2007
  • There are many conflicts or interests among various stakeholders on the development of the coastal area. The integrated methodology, which is reflective of physical conditions, socio-economic circumstances, and people's sense of values, is thus needed to solve the problems. In this study, geographical information systems(GIS) and analytic hierarchy process(AHP) that arc one of multi-criteria analysis methodologies are loosely coupled to develop better analytic procedures for coastal assessment. Socio-economic and environmental parameters of the study area, Hampyung Bay area, are converted to a GIS system-applicable format, while AHP is used to assess the relative importance level of each parameter by calculating weighting factors. After standardizing and rasterizing spatial data from various sources. the weighting factors are applied to produce the layers for each parameter. Map algebra and overlay analyses are used to create the final layer according to the decision making logic or model proposed here. Cell values of that layer could be considered as spatial alternatives. In addition to this finding, the flexibility with the weighing factors enable decision-makers to understand the procedures and alternatives in relevance with selective strategies for coastal management.

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A Study on the Deriving of Areas of Concern for Crime using the Mental Map (멘탈 맵을 이용한 범죄발생 우려 지역 도출에 관한 연구)

  • Park, Su Jeong;Shin, Dong Bin
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.3
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    • pp.177-188
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    • 2019
  • Recently, citizens are feeling anxious as 'Motiveless Crime' increases. The quality of citizens life is degraded and the degree of crime fear is increasing. In this study, based on various variables related to crime other than actual crime occurrence status, crime occurrence points (point line polygon) felt by citizens are created by using mental map methodology. And the purpose of this study is to derive the area of concern for crime through spatial overlap analysis using kernel density estimation analysis. It also uses spatial overlay analysis using kernel density estimation to derive areas of concern for crime occurrence. As a result, the local residents' request point and the areas of concern for crime were overlapped. In addition, the mental map indicating the fear of crime was constructed by mapping mainly the areas between the facilities, the non-construction area such as the narrow area, the security CCTV, the streetlight. This study is meaningful in that it tried to derive a crime occurrence concern area by using mental map method unlike the previous study related to crime. The results of this study, such as mental map, could be used in various fields such as construction of fragile crime map, guideline of crime prevention through environment design.

Agricultural Application of GIS: Establishment and Utilization of Horticultural Field Database (GIS의 농업적 활용: 원예단지의 DB구축 및 활용)

  • Shin, Young Chul;An, Sang Hyun;Park, Young Dal;Kim, Sun Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.2
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    • pp.15-26
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    • 1999
  • A horticultural field database system is constructed for the intelligent farm management using GIS. The database system include both spatial and attribute data of the GIS that can be used as useful information for the farmers every year. The result of the research is summarized as follow; First, the system provides the position, attributes and spatial data of the horticultural farm through AML. Second, the user interface that composed of a basic function menu and application menu is easy to use. Third, the method which applicated overlay and analysis would be need to manage farming data in this horticultural farm and to develop a dynamic decision support system interfaced with GIS.

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GIS overlay analysis for hazard assessment of drought in Iran using Standardized Precipitation Index (SPI)

  • Asrari, Elham;Masoudi, Masoud;Hakimi, Somaye Sadat
    • Journal of Ecology and Environment
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    • v.35 no.4
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    • pp.323-329
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    • 2012
  • The Standardized Precipitation Index (SPI) is a widely used drought index to provide good estimations of the intensity, magnitude and spatial extent of droughts. The objective of this study was to analyze the spatial pattern of drought by SPI index. In this paper, the patterns of drought hazard in Iran are evaluated according to the data of 40 weather stations during 1967-2009. The influenced zone of each station was specified by the Thiessen method. It was attempted to make a new model of drought hazard using GIS. Three criteria for drought were studied and considered to define areas of vulnerability. Drought hazard criteria used in the present model included: maximum severity of drought in the period, trend of drought, and the maximum number of sequential arid years. Each of the vulnerability indicators were mapped and these as well as a final hazard map were classified into 5 hazard classes of drought: one, slight, moderate, severe and very severe. The final drought vulnerability map was prepared by overlaying three criteria maps in a GIS, and the final hazard classes were defined on the basis of hazard scores, which were determined according to the means of the main indicators. The final vulnerability map shows that severe hazard areas (43% of the country) which are observed in the west and eastern parts of country are much more widespread than areas under other hazard classes. Overall, approximately half of the country was determined to be under severe and very severe hazard classes for drought.

The Compensation Cost Analysis of Parcels for Land Alternation according to Occupation Ratio to Road (도로 편입률에 따른 토지이동 대상필지 보상비 분석)

  • Lee, Geun Sang;Park, Jong Ahn;Cho, Mi Su;Cho, Gi Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.1
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    • pp.13-22
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    • 2014
  • Recently, many civil appeals have been occurred in land management work because of discord between cadastral records and actual land use pattern. it is important to select parcels for land alternation exactly using land information and to evaluate compensation cost according to scenarios for advancing this problem. This study operated GIS spatial overlay based on serial cadastral maps and actual-width of the road and analyzed the number and area of the parcels for land alternation by the land classification and ownership applying fuzzy membership function according to occupation ratio to road. Also compensation cost was calculated according to scenarios using individual public land price information of the parcels for land alternation and was arranged by district as Eup and Myeon according to land classification and ownership. This study can efficiently support the work of the parcels for land alternation complying with the financial condition of local government, by supplying compensation cost according to scenarios to the parcels of land alternation by district as Eup and Myeon.

Specialization Strategy for Regional Agriculture Based on the Relationship between Development on Specialized Crops and Impact of Climate Change -Focused on Orchard Crops- (특화작목과 기후변화 간 영향 분석을 통한 지역농업 활성화 전략 연구 -과수를 중심으로-)

  • Hwang, Jae-Hee;Kim, Hyun-Joong;Lee, Seong-Woo
    • Journal of Korean Society of Rural Planning
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    • v.18 no.3
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    • pp.149-164
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    • 2012
  • The purpose of the present study is to construct a rural development strategy from the nexus between spatial changes in specialized crops and suitable cultivation area of the crops. This paper pays particular attention to identify product life cycle of specialized crops in rural areas and estimate the impact of climate change on alterations in spatial distribution of the crops. In order to do so, first of all, this study applies multi-level model (Random coefficient model) to estimate the regional coefficient of five orchard crops. It utilizes the data 1995 to 2010 Korea Agricultural Census. Futhermore, it also adopts overlay analysis by ArcGIS to identify the development path of the crops and the relationship with climate change. Based on the results, it suggests a mechanism activating regional agriculture. The findings propose re-searching and relocating specialized regions of the crops. Especially, it proves each rural area can drive the new agricultural strategy to strengthen regional agriculture by estimating the relationship between development of specialized crops and suitable cultivation areas. For instance, shifting specialized crops in particular regions and enriching genetic or species varieties can be primary measures and it will contribute to improve the reliable base for income sources in the rural communities. This paper also offers specific policy implications regarding rural development plans in response to crops' life cycle and climate changes.

A Fundamental Study on the Maintenance of Administrative Boundaries based on Spatial Information (공간정보기반의 행정경계 정비를 위한 기초연구)

  • Yun, Ji-Ye;Park, Hong-Gi;Choi, Yun-Soo;Nam, Dae-Hyun
    • Spatial Information Research
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    • v.20 no.1
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    • pp.47-57
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    • 2012
  • An Administrative Boundary is the basic of spatial information to cover geographical and regional area. Its importance has arisen in our society at the Smart world era. However, it is difficult to serve exact boundary's lines as administrative boundaries are based on the cadastre lines of land register ; these partly are overlay each other or has gaps. So, it Should be adjusted. But, the maintenance work of administration boundaries causes a conflict or confusion unless we offer concrete procedures and detailed plans previously. Therefore, a rational method is required to prevent side-effects such as confusion, disagreem ent and a conflict etc. In this Study, we present a method and 5 step procedures to make better use in a practical maintenance work. we researched on basic studies of Administrative boundary's concept, history. And we performed a field survey as well as analysis of current problems. considering these results, we suggest usage of various spatial data sources, stake-holders' participation, a method of Nearest district's boundaries to maintain administrative boundaries. Throughout the method, we expect it to serve correct boundary-data to various fields without a big confusion. it is also useful to apply its results not only for re-surveying our land but for recording appropriate boundary-data as rational lines.

The Comparison of Water Quality of Daecheong-Dam basin According to the Data Sources of Land Cover Map (토지피복도 자료원에 따른 대청댐유역 수질특성 비교)

  • Lee, Geun Sang;Park, Jin Hyeog;Choi, Yun Woong
    • Spatial Information Research
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    • v.20 no.5
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    • pp.25-35
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    • 2012
  • This study compared the influence of water quality according to the data sources of spatial information. Firstly, land cover map was constructed through image classification of Daecheong-dam basin and the accuracy of image classification from satellite image showed high as 88.76% in comparison with the large-scaled land cover map in Ministry of Environment, to calculate Event Mean Concentration (EMC) by land cover that impact on the evaluation of nonpoint source pollutant loads. Also curve number and direct runoff were calculated by spatial overlay with soil map and land cover map from image classification. And Seokcheon and Daecheong-Dam basin showed high in the analysis of curve number and direct runoff. Samgacheon-Joint and Sokcheon-Downstream basin showed high in the nonpoint source pollutant loads of BOD from direct runoff and EMC. And Samgacheon-Joint and Bonghwangcheon- Downstream basin showed high in the nonpoint source pollutant loads of TN and TP. Nonpoint source pollutant loads from image classification were compared with those by the land cover map from Ministry of Environment to present the effectivity of nonpoint source pollutant loads from satellite image. And Daecheong-Dam Upstream basin showed high as 10.64%, 11.70% and 20.00% respectively in the errors of nonpoint source pollutant loads of BOD, TN, and TP. Therefore, it is desirable that spatial information including with paddy and dry field is applied to the evaluation of nonpoint source pollutant loads in order to simulate water quality of basin effectively.