• Title/Summary/Keyword: spatial map

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Flood Runoff Analysis using Radar Rainfall and Vflo Model for Namgang Dam Watershed (레이더강우와 Vflo모형을 이용한 남강댐유역 홍수유출해석)

  • Park, Jin-Hyeog;Kang, Boo-Sik;Lee, Geun-Sang;Lee, Eul-Rae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.3
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    • pp.13-21
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    • 2007
  • Recently, very short-term rainfall forecast using radar is required for regional flash flood according to climate change. This research is to evaluate the feasibility of GIS based distributed model using radar rainfall which can express temporal and spatial distribution in actual dam watershed during flood runoff period. Vflo model which was developed Oklahoma university was used as physical based distributed model, and Namgang dam watershed ($2,293km^2$) was applied as study site. Distributed rainfall according to grid resolution was generated by using K-RainVieux, preprocess program of radar rainfall, from JIN radar. Also, GIS hydrological parameters were extracted from basic GIS data such as DEM, land cover and soil map, and used as input data of distributed model(Vflo). Results of this research can provide a base for building of real-time short-term rainfall runoff forecast system according to flash flood in near future.

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A Hybrid Dasymetric Mapping for Population Density Surface using Remote Sensing Data (원격탐사자료를 바탕으로 인구밀도 분포 작성을 위한 하이브리드 대시메트릭 지도법)

  • Kim, Hwa-Hwan;Choi, Jin-Mu
    • Journal of the Korean Geographical Society
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    • v.46 no.1
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    • pp.67-80
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    • 2011
  • Choropleth mapping of population distribution is based on the assumption that people are uniformly distributed throughout each enumeration unit. Dasymetric mapping technique improves choropleth mapping by refining spatially aggregated data with residential information. Further, pycnophylactic interpolation can upgrade dasymetric mapping by considering population distribution of neighboring areas, while preserving the volumes of original units. This study proposed a combined solution of dasymetric mapping and pycnophylactic interpolation to improve the accuracy of population density distribution. Specifically, the dasymetric method accounts for the spatial distribution of population within each census unit, while pycnophylactic interpolation considers population distribution of neighboring area. This technique is demonstrated with 1990 census data of the Athens, GA. with land use land cover information derived from remotely-sensed imagery for the areal extent of populated areas. The results are evaluated by comparison between original population counts of smaller census units (census block groups) and population counts of the grid map built from larger units (census tracts) aggregated to the same areal units. The estimated populations indicate a satisfactory level of accuracy. Population distribution acquired by the suggested method can be re-aggregated to any type of geographic boundaries such as electoral boundaries, school districts, and even watershed for a variety of applications.

Application of UML(Unified Modeling Language) Towards Object-oriented Analysis and Design of Geo-based Data Model (지질 데이터 모델의 객체지향 분석 및 설계를 위한 UML의 적용)

  • Lee, Ki-Won
    • Journal of the Korean earth science society
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    • v.21 no.6
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    • pp.719-733
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    • 2000
  • Normally, a digital geologic map can be defined as mappable one whose spatial information with geographic information details and geologic database attribute, recorded in a digital format that is readable by computer. It shows fundamentally two different conceptual perspectives: cartography for digital mapping and analysis for geo-data processing. While, as both aspects basically relate to natural entities and their interpretation of complex features fused with multi-sources, digital geo-data mapping or geologic mapping, it should be distinguished from digital mapping in engineering such as UIS(Urban Infomation System) and AM/FM(Automated Mapping/Facilities Management). Furthermore, according to short-cycled development of GIS(Geographic Information System) software architecture based on IT(Information Technology) and wide expansion of GIS applications' fields, the importance of domain analysis and application model is emphasized at digital geologic informatizaion. In this paper, first terms and concepts of geo-data model with general data modeling aspects are addressed, and then case histories for geo-data modeling and several approaches for data modeling in GIS application fields are discussed. Lastly, tentative conceptual geo-data modeling by using UML(Unified Modeling Language) of OO(Object-oriented) concepts with respect to USGS/AASG geo-data mode is attempted. Through this approach, the main benefits for standardization and implementation lineage with conceptual model in consideration to reusability are expected. Conclusively, it is expected that geo-information system and its architecture by UML is the new coming key approach for the GIS application in geo-sciences.

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A Study for Natural Conservation Value Assessment of Developing Area - Case Study of Alpensia Resort - (개발 예정지역에서의 자연보전 가치 평가 - 대관령 알펜시아 리조트 조성 예정지역을 사례로 -)

  • Choi Hee-Sun;Cho Dong-Gil;Park Mi-Young;Kim Nam-Gyun;Kim Kwi-Gon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.4 s.111
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    • pp.108-118
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    • 2005
  • While the recent lift of restrictions in greenbelt areas is expected to generate a number of development plans, there are efforts to create various development plans into spatial plans that consider the natural and ecological conditions of development sites. However, these development plans consider Degree of Green Naturality or Degree of Ecology only when designating areas for conservation within development sites. It is true that they don't fully reflect the value of green areas and wetlands as habitats and natural resources. Therefore, this study built an conservation value assessment model that is applicable to sites where development is planned in Korea by reviewing prior case examples md studies and applied the developed model to a case study area. The site where the conservation value assessment model was applied to is an area around Yongsan-ri and Suha-ri, Doam-myon, Pyeongchang-gun, Gangwon province where quality natural resources are located in and wend the site. This is a site for the development of Alpensia Resort where a resort including facilities for the Winter Olympics is planned to be introduced. In order to assess the conservation value of the site for Alpensia Resort, a total of eight items including area, distribution of communities, habitation of species with conservation value, functions of habitats, connectivity of habitats, vegetation layers of forests, age of forests, and ratio of non-native plants were studied through literature review and field surveys. The assessment was made by dividing the site into 95 habitats that are perceived by aerial photographs and each habitat unit was assessed on the eight items in a 3-point scale. Each unit habitat assessed in a 3-point scale was segmented into primary, secondary or tertiary areas based on the conservation value. Habitats assessed as primary were designated as priority (absolute) conservation areas and those assessed as secondary and tertiary were set as secondary conservation areas and tertiary conservation areas, respectively. As a result, each area represented 26.9%, 20% and 3% of total site area. Based on this result, habitat management plans were developed to conserve primary conservation areas, improve secondary conservation areas and restore tertiary conservation areas. In addition, a development plan was developed to create habitats in areas where new habitats are requested in order to build an eco-network in the site and a plan to create eco-corridors was proposed. In developing a land use plan for the site, a development plan that considers conservation areas first should be set up based on the outcome of conservation value assessment. This can be linked to the development of an environment-friendly land use plan as well as easing the establishment of a green area and eco-network. This study will facilitate the implementation of the 'conservation before development' principle, which can prevent reckless development, by assessing conservation value in setting up development plans.

Classification of Local Climate Zone by Using WUDAPT Protocol - A Case Study of Seoul, Korea - (WUDAPT Protocol을 활용한 Local Climate Zone 분류 - 서울특별시를 사례로 -)

  • Kim, Kwon;Eum, Jeong-Hee
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.4
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    • pp.131-142
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    • 2017
  • This study aims to create a Local Climate Zone(LCZ) map of Seoul by using World Urban Database and Access Portal Tools(WUDAPT) protocol, and to analyze the characteristics of the Seoul LCZs. For this purpose, training samples of 17 LCZ types were collected by using Landsat images and Google Earth. LCZ Classification and Filtering were performed by SAGA GIS. An ArcGIS was used to analyze the characteristics of each LCZ type. The characteristics of the LCZ types were analyzed by focusing on building surface fraction ratio, impervious surface fraction ratio, pervious surface fraction ratio, building stories and air temperature. The results show that one filtering was found to be most appropriate. While Yangcheongu and Yeongdeungpogu with the higher annual and maximum mean air temperature than other areas have the higher rate of LCZ 3(compact low-rise) and LCZ 4(open high-rise), Jongnogu, Eunpyeonggu, Nowongu and Gwanakgu with the lower value have the higher rate of LCZ A(Dence trees). The values of building surface fraction ratio, impervious surface fraction ratio and building stories of each LCZ were included in the range of WUDAPT for most LCZs. However, the values of pervious surface fraction ratio were out of the range, in particular, in the LCZs 4~6 and 9~10. This study shows the usability and applicability of the WUDAPT methodology and its climate zone classification used in many countries as a basic data for the landscape planning and policy to improve the thermal environment in urban areas.

A Study on the Coordinate-based Intersection ID Composition System Using Space Filling Curves (공간 채움 곡선을 활용한 좌표 기반의 교차로 ID 구성 체계에 관한 연구)

  • Lee, Eun il;Park, Soo hong;Kim, Duck ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.6
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    • pp.124-136
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    • 2019
  • Autonomous driving at intersections requires assistance by exchanging traffic information between traffic objects due to the intersection of various vehicles and complicated driving environment. For this reason, traffic information exchange between adjacent intersections is required, but the node ID representing the intersection in the Korean standard node link system have limitations in updating intersections and identifying location information of intersections through IDs due to the configuration system including serial numbers. In this paper, we designed a coordinate-based intersection ID configuration system created by processing and merging two-dimensional coordinates of intersections to include location information in the intersection ID. In order to verify the applicability of the proposed intersection ID, we applied a new intersection ID to domestic intersections and confirmed that there are no duplicate values. Coordinate-based intersection ID reduces data size by 60% compared to existing node ID, and enables spatial queries such as searching for nearby intersections and extracting intersections in specific areas in the form of boxes without GIS tools. Therefore, coordinate-based intersection ID is expected to be more scalable and utilized than existing node ID.

Characteristics of Greenup and Senescence for Evapotranspiration in Gyeongan Watershed Using Landsat Imagery (Landsat 인공위성 이미지를 이용한 경안천 유역 증발산의 생장기와 휴면기 분포 특성 분석)

  • Choi, Minha;Hwang, Kyotaek;Kim, Tae-Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1B
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    • pp.29-36
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    • 2011
  • Evapotranspiration (ET) from the various surfaces needs to be understood because it is a crucial hydrological factor to grasp interaction between the land surface and the atmosphere. A traditional way of estimating it, which is calculating it empirically using lysimeter and pan evaporation observations, has a limitation that the measurements represent only point values. However, these measurements cannot describe ET because it is easily affected by outer circumstances. Thus, remote sensing technology was applied to estimate spatial distribution of ET. In this study, we estimated major components of energy balance method (i.e. net radiation flux, soil heat flux, sensible heat flux, and latent heat flux) and ET as a map using Mapping Evapo-Transpiration with Internalized Calibration (METRIC) satellite-based image processing model. This model was run using Landsat imagery of Gyeongan watershed in Korea on Feb 1, 2003 and Sep 13, 2006. Basic statistical analyses were also conducted. The estimated mean daily ETs had respectively 22% and 11% of errors with pan evaporation data acquired from the Suwon Weather Station. This result represented similar distribution compared with previous studies and confirmed that the METRIC algorithm had high reliability in the watershed. In addition, ET distribution of each land use type was separately examined. As a result, it was identified that vegetation density had dominant impacts on distribution of ET. Seasonally, ET in a growing season represented significantly higher than in a dormant season due to more active transpiration. The ET maps will be useful to analyze how ET behaves along with the circumstantial conditions; land cover classification, vegetation density, elevation, topography.

Application of Hydroacoustic System and Kompsat-2 Image to Estimate Distribution of Seagrass Beds (수중음향과 Kompsat-2 위성영상을 이용한 해초지 분포 추정)

  • Kim, Keunyong;Eom, Jinah;Choi, Jong-Kuk;Ryu, Joo-Hyung;Kim, Kwang Yong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.3
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    • pp.181-188
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    • 2012
  • Despite the ecological importance of seagrass beds, their distributional information in Korean coastal waters is insufficient. Therefore, we used hydroacoustic system to collect accurate bathymetry and classification of seagrass, and Kompsat-2 (4 m spatial resolution) image for detection of seagrass beds at Deukryang Bay, Korea. The accuracy of Kompsat-2 image classification was evaluated using hydracoustic survey result using error matrix and Kappa value. The total area of seagrass beds from satellite image classification was underestimated compared to the hydroacoustic survey, estimated 3.9 and $4.5km^2$ from satellite image and hydroacoustic data, respectively. Nonetheless, the accuracy of Kompsat-2 image classification over hydroacoustic-based method showing 90% (Kappa=0.85) for the three class maps (seagrass, unvegetated seawater and aquaculture). The agreement between the satellite image classification and the hydroacoustic result was 77.1% (the seagrass presence/absence map). From our result of satellite image classification, Kompsat-2 image is suitable for mapping seagrass beds with high accuracy and non-destructive method. For more accurate information, more researches with a variety of high-resolution satellite image will be preceded.

Integrated Color Matching in Stereoscopic Image by Combining Local and Global Color Compensation (지역과 전역적인 색보정을 결합한 스테레오 영상에서의 색 일치)

  • Shu, Ran;Ha, Ho-Gun;Kim, Dae-Chul;Ha, Yeong-Ho
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.12
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    • pp.168-175
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    • 2013
  • Color consistency in stereoscopic contents is important for 3D display systems. Even with a stereo camera of the same model and with the same hardware settings, complex color discrepancies occur when acquiring high quality stereo images. In this paper, we propose an integrated color matching method that use cumulative histogram in global matching and estimated 3D-distance for the stage of local matching. The distance between the current pixel and the target local region is computed using depth information and the spatial distance in the 2D image plane. The 3D-distance is then used to determine the similarity between the current pixel and the target local region. The overall algorithm is described as follow; First, the cumulative histogram matching is introduced for reducing global color discrepancies. Then, the proposed local color matching is established for reducing local discrepancies. Finally, a weight-based combination of global and local matching is computed. Experimental results show the proposed algorithm has improved global and local error correction performance for stereoscopic contents with respect to other approaches.

Efficiency Algorithm of Multispectral Image Compression in Wavelet Domain (웨이브릿 영역에서 다분광 화상데이터의 효율적인 압축 알고리듬)

  • Ban, Seong-Won;Seok, Jeong-Yeop;Kim, Byeong-Ju;Park, Gyeong-Nam;Kim, Yeong-Chun;Jang, Jong-Guk;Lee, Geon-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.4
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    • pp.362-370
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    • 2001
  • In this paper, we proposed multispectral image compression method using CIP (classified inter-channel prediction) and SVQ (selective vector quantization) in wavelet domain. First, multispectral image is wavelet transformed and classified into one of three classes considering reflection characteristics of the subband with the lowest resolution. Then, for a reference channel which has the highest correlation and the same resolution with other channels, the variable VQ is performed in the classified intra-channel to remove spatial redundancy. For other channels, the CIP is performed to remove spectral redundancy. Finally, the prediction error is reduced by performing SVQ. Experiments are carried out on a multispectral image. The results show that the proposed method reduce the bit rate at higher reconstructed image quality and improve the compression efficiency compared to conventional methods. Index Terms-Multispectral image compression, wavelet transform, classfied inter-channel prediction, selective vetor quantization, subband with lowest resolution.

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