• Title/Summary/Keyword: landform analysis

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The Generation of Digital Orthophotos and Three Dimensional Models of an Urban Area from Digital Aerial Photos

  • Lee, Jin-Duk
    • Korean Journal of Geomatics
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    • v.2 no.2
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    • pp.131-137
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    • 2002
  • The digital photogrammetric products have been increasingly used as an accurate foundation for representing information associated with infrastructure management. The technological advances in merging raster and vector data within the framework of GIS have allowed for the inclusion of DTMs and digital orthophotos with vector data and its associated attributes. This study addresses not only generating DEMs and digital orthophotos but producing three dimensional building models from aerial photos of an urban area by employing the digital photogrammetric technology. DEMs and digital orthophotos were automatically generated through the process of orientations, image matching and so on, and then the practical problems, which must be solved especially in applying to urban areas, were considered. The accuracy of produced digital orthophotos was derived by using check points. Also three dimensional visualization imagery, which is useful in the landform analysis, and 3D building models were produced. Digital photogrammetric products would be used widely not only as GIS framework data layers by using the GIS link function which links attribute and image information in the database for applying to infrastructure management and but as geospatial data for especially 3D GIS in urban areas.

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Analysis on Fault-Related Landformsin the Gyeongju Area of the Yangsan Fault Valley (양산 단층곡 경주 지역의 단층 지형 분석)

  • Park, Chung-Sun;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.1
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    • pp.19-30
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    • 2018
  • This study tries to infer fault lines and produce a map for the lines based on a classification of fault-related landforms and fluvial landformsin the Gyeongju area of the Yangsan Fault Valley. Fault activities in the study area are thought to be older than the time of river formation or stronger than the erosion by river, while the northern and southern parts of the study area seem to have experienced fault activities after valley formation. It is also possible that weaker fault activities than the erosion by river seem to have been prevailed in the parts. In the study area, the Gyeongju alluvial fan is located within a wide erosional valley at the joint area of the Yangsan and Ulsan Faults. From the distribution of the landforms, it is inferred that several fault lines parallel to the Yangsan Fault are distributed at both sides of the fault valley. In particular, the area from Bae-dong to Nogok-ri, Naenam-myeon shows the most obvious linearity of the landforms within the study area. Several fault lines with a direction of NNE-SSW are also found around the epicenter of the 2016 Gyeongju Earthquake.

Types and Geomorphic Development of Large Landslides in the Kokomeren River Basin, Kyrgyzstan (키르기스스탄 코코메렌강 유역의 대규모 산사태 유형과 지형 발달)

  • Oh, Jeong-Sik
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.1
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    • pp.1-14
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    • 2019
  • Large landslide is a type of mass movement that causes drastic landform changesin a short period, and it causes huge human and property damage over a large area. The purpose of this study is to categorize the types and characteristics of large landslides around the Kokomeren River basin, Kyrgyzstan and to discuss the geomorphic development after the large landslides. The topographic analysis about a total of 20 landslides documented collapsed volumes of 0.01 to 1.10 km3, height drops of 180 to 1,770 m, and runout distances of 1,200 to 5,400 m. Rock avalanche and rockslide are identified as major types of large-scale landslides in the study area. Rock avalanches can be divided into P-type, J-type, and S-type based on the features of slope failure and kinematic characteristics of rock debris. Landslide synchronistic landforms such as trimlines, transverse ridges, longitudinal ridges, levees, and hummocks are well developed in the rock avalanche. The pieces of evidence of landslide dam, landslide-dammed lake, and remnant outburst flood deposits are observed in the upstream and downstream where the rockslides occurred. The Ak-Kiol landslide dam is the best example of a geomorphic development due to lake spillover and the large landslides were likely to be triggered by huge paleo-seismic events.

Risk Factors Analysis and Quantitative Risk Assessment Model for Plant Construction Project (플랜트 건설 리스크 분석 및 리스크 정량화 모델 개발에 관한 연구)

  • Ahn, Sung-Jin;Kim, Tae-Hui;Nam, Kyung-Yong;Kim, Ji-Myong
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.1
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    • pp.77-86
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    • 2019
  • Due to the increasing demand for and complexity of plant construction projects, unpredictable risk factors are on the consequent increase. For that reason, the quantitative risk analysis is being called for, in order for the development of a risk assessment model using risk indicators for the plant construction projects. This study used the claim payout data collected at a global insurance company to reflect the actual financial losses in plant construction projects as dependent variables in the risk assessment model. In terms of independent variables, the geographic information, i. e., landform, and the construction information including test-run, schedule rate, total cost and duration are adopted. In addition, this study suggests that the regression model containing such independent variables that are statistically significant can be applied to as a foundational guideline for the plant construction project risk analysis during the phase of construction and commissioning.

Analysis of Importance of Damaged Area Assessment Indices using Analytic Hierarchy Process (AHP 기법을 활용한 훼손지 평가항목의 중요도 분석)

  • Song, Ki-Hwan;Choi, Yun-Eui;Seok, Young-Sun;Jeon, Seong-Woo;Sung, Hyun-Chan;Seo, Jung-Young;Chon, Jin-Hyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.6
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    • pp.15-28
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    • 2020
  • Urbanization and industrialization have caused increasing damage to national lands, and ecological restoration has proceeded without any specific assessment of this damage. The purpose of this study is to select indices to assess damaged areas through literature review and panel discussions, and to derive the importance of damaged area assessment indices by analyzing them through the Analytic Hierarchy Process (AHP). This study has derived, via literature review, six types of damage and a total of 18 related assessment indices. A total of 51 responses were collected from surveys and given to experts, and an AHP analysis conducted. As a result of the analysis, "Landform change (0.268)" was of the highest importance, with associated damage types as follows: "Soil contamination (0.193)", "Vegetation damaged (0.149)", "Surface soil loss (0.143)", "Change in soil physiochemical property (0.125)", and "Vegetation decline (0.122)". The analysis determined that the item of the highest importance in the overall assessment of damage was "Slope occurred area (0.100)", and that "Conductivity (0.022)" was of the lowest importance. This study can be presented as a criterion in determining the type and degree of damage in setting priorities for future ecological restoration projects.

Extraction of Lineament and Its Relationship with Fault Activation in the Gaeum Fault System (가음단층계의 선형구조 추출과 선형구조와 단층활동의 관련성)

  • Oh, Jeong-Sik
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.2
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    • pp.69-84
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    • 2019
  • The purpose of this study is to extract lineaments in the southeastern part of the Gaeum Fault System, and to understand their characteristics and a relationship between them and fault activation. The lineaments were extracted using a multi-layered analysis based on a digital elevation model (5 m resolution), aerial photos, and satellite images. First-grade lineaments inferred as an high-activity along them were classified based on the displacement of the Quaternary deposits and the distribution of fault-related landforms. The results of classifying the first-grade lineaments were verified by fieldwork and electrical resistivity survey. In the study area of 510 km2, a total of 222 lineaments was identified, and their total length was 333.4 km. Six grade lineaments were identified, and their total length was 11.2 km. The lineaments showed high-density distribution in the region along the Geumcheon, Gaeum, Ubo fault, and a boundary of the Hwasan cauldron consisting the Gaeum Fault System. They generally have WNW-ESE trend, which is the same direction with the strike of Gaeum Fault System. Electrical resistivity survey was conducted on eight survey lines crossing the first-grade lineament. A low-resistivity zone, which is assumed to be a fault damage zone, has been identified across almost all survey lines (except for only one survey line). The visual (naked eyes) detecting of the lineament was evaluated to be less objectivity than the automatic extraction using the algorithm. However, the results of electrical resistivity survey showed that first-grade lineament extracted by visual detecting was 83% reliable for inferred fault detection. These results showed that objective visual detection results can be derived from multi-layered analysis based on tectonic geomorphology.

Cosmogenic Nuclides Dating of the Earth Surface: Focusing on Korean Cases (우주선유발 동위원소를 이용한 지표면의 연대측정: 국내 사례를 중심으로)

  • Seong, Yeong Bae;Yu, Byung Yong
    • The Journal of the Petrological Society of Korea
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    • v.23 no.3
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    • pp.261-272
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    • 2014
  • Over the last three decades, advances in AMS (Accelerator Mass Spectrometry) and Noble Gas Mass Spectrometer make various application of terrestrial cosmogenic nuclides (CNs) to wide range of earth surface sciences possible. Dating techniques can be divided into three sub-approaches: simple surface exposure dating, depth-profile dating, and burial dating, depending on the condition of targeted surfaces. In terms of Korean landscape view, CNs dating can be applied to fluvial and marine terrace, alluvial fan, tectonic landform (fault scarp and faulted surfaces), debris landforms such as rock fall, talus, block field and stream, lacustrine and marine wave-cut platform, cave deposits, Pliocene basin fill and archaeological sites. In addition, in terms of lithology, the previous limit to quartz-rich rocks such as granite and gneiss can be expanded to volcanic and carbonate rocks with the help of recent advances in CNs analysis in those rocks.

Three Dimensional Analysis Using Digital Elevation Model on the Coastal Landform of the Sacheon Bay, South Sea of Korea (수치고도 모델을 이용한 사천만 해안지역의 3차원 지형분석)

  • Lee, Min-Boo;Kim, Nam-Shin;Han, Kyun-Hyeung
    • Journal of the Korean association of regional geographers
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    • v.9 no.2
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    • pp.203-216
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    • 2003
  • The process of constructing coastal digital elevation model(DEM), for the 3 dimensional analysis, is composed by abstracting land layers for land elevation and water depth, reprojecting UTM, relocating geographical grid, and interpolating works. The geomorphic set of shallow sea, including tidal current, tidal zone deposition, and water depth distribution, was analyzed by eye search of Landsat TM image, masking of land zone, band combination and regression analysis. Some horizontal differences, between combined DEM and surveyed data of shallow sea, was corrected for analysis. Analyzed geomorphic elements are stream channel, alluvial fan, coastal terrace, tidal current. and shallow sea bank. Results of analysis present that transported fluvial materials influence tidal sedimentation, especially from Gahwacheon river, for the role of artificial draining flooding waters from Jinyang Reservoir, almost in the summer season. In the coastal area with less tidal current, more fine materials are deposited. The influence of currental deposition are higher on small pockets with west coast of well developed terraces. The lower skirt of alluvial fans developed into the tidal zone of shallow sea. Small pocket type bays are closed by coastal current, and less influenced from tidal deposition. The bank of Jinju Bay are developed originally from submerging of remnant erosional mountain ranges, and play on the role of trapping fine materials.

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The Developmental Directions and Classification of Regional Types Based on Natural Resources (자연자원에 기반한 지역유형분류와 발전방안)

  • Park, Jong-Jun;Yoon, Ki-Ran;Park, Chang-Sug
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.2
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    • pp.10-17
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    • 2011
  • The paradigm of the use and management of natural resources is changing. Wise use of natural resources can be achieved by enhancing their conservation value and, at the same time, taking them as an opportunity for regional development. It leads to an idea of pursuing regional development by making good use of natural resources. In this paper, natural resources were classified as living species resources, ecosystem and landscape resources, and non-living resources. The resources were divided into 27 detailed analysis indices. The administrative boundaries of 165 municipalities in Korea were defined as spatial analysis units. Finally, a spatial database of natural resources was built. To classify the regional types, we conducted factor analyses with a detailed index of natural resources and a cluster analysis with the factor value. As the result of the factor analysis, six factors have been deduced as follows: forest resources, landscape resources, coastal ecology resources, inland water resources, landform resources, and ecology visit resources. In addition, the cluster analyses were conducted for the points of the factors drawn. The final classification consists of nine groups, and appropriate methods for each regional development have been suggested. Results of this study will contribute to providing fundamental materials for site selection and objective-setting for regional development policies and planning in consideration of natural resources.

A Study on Disaster Recognition and Feasibility of Disaster Prevention Based on Place Names (지명을 통해 본 재해인식 및 방재 가능성 탐색)

  • Kim, Sun-Hee;Park, Kyeong
    • Journal of the Korean association of regional geographers
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    • v.16 no.5
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    • pp.457-473
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    • 2010
  • Patterns and regional distribution of disaster-related place names have been analyzed to confirm the recognition and probability of disaster and to explore the possibility of disaster prevention measures. 106 terms and 37,901 place names related to disaster and prevention measures have been collected from the Korean gazetteers "Hanguk Jimyeong Chongnam". Based on this, some conclusions have been drawn: firstly, place names related to the geomorphic processes and prevention measures are more common than any other disasters; secondly, place names related to heavy rain, flooding and drowning are most common. Analysis of the regional distribution pattern shows that disaster-related place names are most common in Jeolla and Gyeongsang Provinces and general place names reflecting environmental concern such as water, sand, plain, rain and dam are distributed evenly throughout the whole country; howe, r, place names such as dumbeong, gureong, yeoul, tan(灘), bangjuk, je(堤), and ji(池) are restricted to the specific region, which shows that place names reflects the locational and toprn sucic ainuations. Case st, anindicates that prevention measures should be focused on tributaries and srill villeys conaid ring that disasters originated from the combination of weather and landform conditions are most common throughout the whole country.

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