• Title/Summary/Keyword: Aerial Photographs

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A Study on the Distribution Characteristics of the Small Village Wetlands in Mountainous Rural Area - Case on Geumsan-gun, Chungnam - (산지 읍면지역 소규모 마을습지 분포 특성 연구 - 충남 금산군을 사례로 -)

  • Park, Mi-Ok;Seo, Joo-Young;Yang, Seung-Bin;Koo, Bon-Hak
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.6
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    • pp.37-44
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    • 2019
  • This study was conducted to identify the distribution characteristics of small village wetlands in Geumsan County, an inland mountain zone, and comparing with Seocheon County, a coastal plain area with different ecological environment characteristics. Using Arc-GIS (v10.1) the village wetland code was extracted to derive the possible location of the village wetland, and the final distribution of the village was obtained by performing indoor judging work based on satellite images, aerial photographs, topographical maps, Korea Land Information System (KLIS), land use level, land cover degree (division), and land use status by local surveying and indoor analyzing. Although Geumsan County (576.66km2) is more than 60% larger than Seocheon County (358.04km2), 607 villages in Geumsan County and 570 villages in Seocheon County are capable of making similar levels of 106.5% of wetlands, but only a fraction of those in Seocheon County were found to be 67.6%. The density of the village wetlands was much lower than that of Seocheon County, a coastal plain area, because there were many mountainous areas in Geumsan County, and most of the wetlands temporarily created for water supply were removed during the analysis phase of the Jeongsa Image, so the actual wetlands of the village were judged to be only two-thirds different from those of Seocheon County.

Development of Learning Place for Geologic Field Survey around the Duta Mountain, Chungbuk, Korea (충북 괴산군 두타산 일대의 야외지질조사 학습장 개발)

  • Lee, Chang-Xin;Cheong, Sang-Won
    • Journal of the Korean earth science society
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    • v.26 no.1
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    • pp.41-57
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    • 2005
  • The purpose of the study is to develop a educational data in order for students to perform geologic field survey effectively by themselves. A area around the Duta Mountain is selected. which is located at the southeastern part of Eumsung sedimentary basin because various rock types and geologic structures are well shown in this area and also it is convenient to reach there. Thirteen stops for observation are chosen m a route f3r exercising field geologic investigation. Data for field research are given and described in detail from each stop for observation. To do this, students make their own route map using general or digital geographic map and aerial photo is added to know relationship between large-scale structure and different rock types regionally. Moreover, it is designed to minimize conflict factors that may be experienced from the real field survey by showing outcrop photographs and polarizing photomicrographs of rut samples related to each stop and geologic structures. The attitude of students is investigated with the data of field geologic survey for students of an Earth Science class in the College of Education in Chungbuk National University. The results indicate that the educational data for geologic field survey brought positive changes that greatly help students perform field survey in definitive side, especially formation of absolute concepts on earth science.

Landslide Susceptibility Mapping Using Ensemble FR and LR models at the Inje Area, Korea (FR과 LR 앙상블 모형을 이용한 산사태 취약성 지도 제작 및 검증)

  • Kim, Jin Soo;Park, So Young
    • Journal of Korean Society for Geospatial Information Science
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    • v.25 no.1
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    • pp.19-27
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    • 2017
  • This research was aimed to analyze landslide susceptibility and compare the prediction accuracy using ensemble frequency ratio (FR) and logistic regression at the Inje area, Korea. The landslide locations were identified with the before and after aerial photographs of landslide occurrence that were randomly selected for training (70%) and validation (30%). The total twelve landslide-related factors were elevation, slope, aspect, distance to drainage, topographic wetness index, stream power index, soil texture, soil sickness, timber age, timber diameter, timber density, and timber type. The spatial relationship between landslide occurrence and landslide-related factors was analyzed using FR and ensemble model. The produced LSI maps were validated and compared using relative operating characteristics (ROC) curve. The prediction accuracy of produced ensemble LSI map was about 2% higher than FR LSI map. The LSI map produced in this research could be used to establish land use planning and mitigate the damages caused by disaster.

Extraction of the Tree Regions in Forest Areas Using LIDAR Data and Ortho-image (라이다 자료와 정사영상을 이용한 산림지역의 수목영역추출)

  • Kim, Eui Myoung
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.2
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    • pp.27-34
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    • 2013
  • Due to the increased interest in global warming, interest in forest resources aimed towards reducing greenhouse gases have subsequently increased. Thus far, data related to forest resources have been obtained, through the employment of aerial photographs or satellite images, by means of plotting. However, the use of imaging data is disadvantageous; merely, due to the fact that recorded measurements such as the height of trees, in dense forest areas, lack accuracy. Within such context, the authors of this study have presented a method of data processing in which an individual tree is isolated within forested areas through the use of LIDAR data and ortho-images. Such isolation resulted in the provision of more efficient and accurate data in regards to the height of trees. As for the data processing of LIDAR, the authors have generated a normalized digital surface model to extract tree points via local maxima filtering, and have additionally, with motives to extract forest areas, applied object oriented image classifications to the processing of data using ortho-images. The final tree point was then given a figure derived from the combination of LIDAR and ortho-images results. Based from an experiment conducted in the Yongin area, the authors have analyzed the merits and demerits of methods that either employ LIDAR data or ortho-images and have thereby obtained information of individual trees within forested areas by combining the two data; thus verifying the efficiency of the above presented method.

Studies on the Changes of Forest Land Use - Especially around Tae Kwan Ryoung Region - (산지이용(山地利用) 변천(變遷)에 관(關)한 연구(硏究) - 대관령주변(大關嶺周辺)을 중심(中心)으로-)

  • Kim, K.D.;Han, K.J.;Park, J.W.;Song, J.H.;Lee, S.H.
    • Journal of Korean Society of Forest Science
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    • v.57 no.1
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    • pp.20-25
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    • 1982
  • This study was carried out to investigate the changes of forest land use around Tae Kwan Ryoung region during 15 years, by using the aerial photographs in 1965 and 1980 respectively. the results are summarized as follows: 1) The areas of forest land and farm land has been decreased, while the grass land increased as 3 times. It is because that the site of Tae Kwan ryoung region was suitable for livestock breeding and the wide grass lands were developed. 2) With a view to forest land use, it is desirable to convert the forest land into grass land and farm Land. But it should be considered the fact that most of the farm land was converted into forest land, in the utilization of forest land in future. 3) Due to the development of industries such as livestock breeding and leisure industry, there is a great increase in the dwelling houses, stalls, public building and habitants in this region. Therefore, in future we should establish the plans of forest land use synthetically and efficiently, considering the promotion of indirect utilities such as soil conservation, recreation and environmental protection as well as timber production.

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Locations and Topographical Character of the MAEULSOOP in the Southwestern and the Eastern Region (마을숲의 분포 위치와 지형적 공간특성 유형화 방안 - 경북 의성, 전북 진안 및 전남 함평지역을 대상으로)

  • Kwon, Jino;Oh, Jeong-Hak;Lee, Jeong-Youn;Park, Chan-Ryul;Choi, Myoung-Sub
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.85-93
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    • 2008
  • The MAEULSOOP, Korean traditional village groves have been installed and survived since 7th Century to serve local village dwellers as a community forest. The common sense of their reasons for being is related to the surroundings such as hills, waterways and wind-ways. To understand the roles in a local community, spatial characteristics of distribution, locations and shapes were tested at the two-characterized regions, the Southwestern Flat Region and the Eastern Hilly Region. Approximately more than 500 written evidences related to trees and forests were surveyed, for example village names, folk tales and lists of designated trees for protection. Twenty sites in each region were selected and tested for the spatial analysis. Aerial photographs, DEM and the ArcGIS with a modified AML for slope analysis are applied based on the criteria of the KLCIS(Kwon, 2002; 권진오, 2008). The major factors in the role of the MAEULSOOP based on the spatial character of two regions are; the array and locations of hills for encircling or exposure, locations against corridors and waterway or not, locations of the community to serve, the conservation of energy. Although locations and shapes of the MAEULSOOP are slightly different, it seems that one of the prime roles is what makes their everyday life difficult the most in the community.

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Characteristics of Sediment Transport due to the Construction of Jetty at the Heoya-River Mouth, Ulsan (울산 회야강 하구 도류제 건설에 따른 표사이동 특성)

  • Lee, Seong-Dae;Kim, Bong-Ik
    • Journal of Wetlands Research
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    • v.16 no.4
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    • pp.477-486
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    • 2014
  • Integrated sand control including sediment discharge from hinterland rivers is necessary to maintain coastal sand resources over a long term. In this regard, the following subjects should be considered; efficient ways to transfer discharged sand from a river to the neighboring coast, measures to improve storage efficiency of the discharged sand at the river delta and/or river terrace, measures to prevent the sand resources from being discharged into the deep sea during flooding. From the 1997 to January 2004, the jetty of 156 m length was constructed the Heoya-river mouth to protect the blockade of river mouth. Several tests were carried out to investigate the characteristics of sediment transport and morphological change due to the construction of the jetty at the Heoya-river mouth. Firstly, The sand discharge from Heoya river is quantified by one-dimensional numerical analysis assuming the mixed sand of three different particle diameters. Also the numerical mode system, which predicts the sea bed changes obtained from the Bailard's energy model(1981), was combined with the wave, wave-induced currents and sediment transport models. Then, to understand the changes to the blockade of the river mouth, several aerial photographs were compared, which showed that the changes were significant.

Geospatial Data Modeling for 3D Digital Mapping (3차원 수치지도 생성을 위한 지형공간 데이터 모델링)

  • Lee, Dong-Cheon;Bae, Kyoung-Ho;Ryu, Keun-Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.3
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    • pp.393-400
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    • 2009
  • Recently demand for the 3D modeling technology to reconstruct real world is getting increasing. However, existing geospatial data are mainly based on the 2D space. In addition, most of the geospatial data provide geometric information only. In consequence, there are limits in various applications to utilize information from those data and to reconstruct the real world in 3D space. Therefore, it is required to develop efficient 3D mapping methodology and data for- mat to establish geospatial database. Especially digital elevation model(DEM) is one of the essential geospatial data, however, DEM provides only spatially distributed 3D coordinates of the natural and artificial surfaces. Moreover, most of DEMs are generated without considering terrain properties such as surface roughness, terrain type, spatial resolution, feature and so on. This paper suggests adaptive and flexible geospatial data format that has possibility to include various information such as terrain characteristics, multiple resolutions, interpolation methods, break line information, model keypoints, and other physical property. The study area was categorized into mountainous area, gently rolling area, and flat area by taking the terrain characteristics into account with respect to terrain roughness. Different resolutions and interpolation methods were applied to each area. Finally, a 3D digital map derived from aerial photographs was integrated with the geospatial data and visualized.

Establishment of Optimum Photo Condition for the Accurate Monitoring of Cultural Assets and Ground Facilities using Terrestrial Photographs (문화재와 지상시설물의 정밀점검을 위한 지상사진의 최적촬영조건 설정)

  • 손덕재
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.12 no.1
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    • pp.1-13
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    • 1994
  • The terrestrial phetogrammetry has the relative convenience of selecting the site of photo station in contrast with the aerial photogrammetry, and the flexibility in accuracy prediction of object point positioning. So it has the advantage in designing optimum photo taking system which can fulfill the required accuracy. For the convergent photos which are frequently used for the monitoring of cultural assets and ground facilities, almost all of the traditional studies for the optimum photo condition, both in theoretical or experimental, are basically depend on the symmetrical configuration at the normal direction to the center of the object. However, in many cases the surroundings of the object do not allow the normal photo direction or sufficient convergent angle, even more the object features are not always be seen as one panel like planar. In this paper, the accuracy variation of convergent photos for the multi-planar objects, which are composed by some orthogonal planes, are investigated to establish the optimum photo condition. The results of the accuracy analysis for the photo direction, convergent angle, as well as the object feature are expected to be utilized in system design of geometric configuration of convergent photos, which are adequate for the accurate monitoring of the objects, such as culural assets, facilities, precision instruments, deformation surveying, etc.

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A study on the Realtime Update of the Digital-Map by the General Survey Map (일반측량성과도에 의한 수치지도의 수시갱신방법 연구)

  • Lee, Sang-Gil;Kwon, Jay-Hyoun;Jeon, Jae-Han
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.3
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    • pp.19-26
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    • 2007
  • The renewal update of the digital map constructed through NGIS has been conducted for the enhancement of usage, maintenance so that the latest data is guaranteed. The total update has been done every five years for five regions of the country using aerial photographs and satellite images. By launching the third phase of NGIS, the updating plan was changed from total to total or partial update including the real time update scheme. Furthermore, the update period was improved from five to two years and four years for a large and a small city, respectively. Therefore, it is necessary to develope a matching technique which combines various geographic information (such as drawing map, surveying drawing and map) with exact position on the digital map. In this study, we developed a matching algorithm based on central point and suggested a method which uses general surveying drawing for revision/update of the digital map. The general survey is conducted when a civilian development on lands are approved. Thus, the outcome from the survey, which is the general survey drawing, contains the latest various contents such as road, building, water pipe and manhole. A consistent and efficient method using the general survey drawing for near real time update of the digital map by applying the developed matching algorithm is presented.

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