• Title/Summary/Keyword: topography of land

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The Topography Characteristics on the Land Creep in Korea (우리나라 땅밀림지의 지형 특성)

  • Park, Jae-Hyeon;Seo, Jung Il;Lee, Changwoo
    • Journal of Korean Society of Forest Science
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    • v.108 no.1
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    • pp.50-58
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    • 2019
  • This study was carried out to analysis the landform characteristics of land creep areas in south Korea. Aspect ratio in 17 areas (approximately 46.0 %) among total land creep areas (37 areas) was ranged from 0.37 to 0.92. Also, aspect ratio in 36 areas (approximately 97.0 %) was less than 2. Longitudinal section form ratio of 15 areas (approximately 41.0 %) was less than 1.0, whereas 22 areas (approximately 59.0 %) were more than 1.0. Horseshoe hoof form in land creep areas were mostly appeared to flat land types, whereas convex terrain ground form was prevailed to micro-topography. Mean contour intervals were higher in micro-topography (mean 29.4 m, range 9.5 m ~ 83.2 m) than in except micro-topography (mean 24.3 m, range: 14.4 m ~ 59.4 m) in land creep areas. The contour intervals were slightly wider in micro-topography (mean 5.1 m, range: 4.9 m ~ 23.8 m) than in except micro-topography in land creep areas. The results indicate that contour intervals were significantly different (P < 0.05) between micro-topography and except micro-topography in land creep areas.

Spatial Information Data Construction and Data Mining Analysis for Topography Investigation of Land Characteristics (토지특성 고저조사를 위한 공간정보 데이터 구축과 데이터 마이닝 분석)

  • Choi, Jin Ho;Kim, Jun Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.6
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    • pp.507-516
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    • 2019
  • The investigation of land characteristics is an important task for the calculation of officially land prices and standard comparison table of land price. Therefore, it should be done objectively and consistently. However, the current investigation system is mainly done by researcher's subjective judgment. Therefore, the objectivity and consistency of this investigation is not guaranteed and questionable. In this study, we first defined the problem by analyzing the current land topography investigation method. In addition, in order to investigate the land topography, the geometry of the parcel is quantified by spatial information and applied to the decision tree based method(C4.5) to produce the final result. This study intended to extract the parcel characteristics data of the topographic by the use of spatial information and to apply the information to the C4.5, there by suggesting a method for addressing the problems. The findings showed approximately 93.5% between the results of topography classification estimated with rules learned by C4.5.

Land Surface Dynamics and Underwater Topography from the Latest DTM Extraction to Measure the Antarctica Ice Sheet Thickness

  • Atriyon Julzarika
    • Ocean and Polar Research
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    • v.46 no.1
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    • pp.65-82
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    • 2024
  • The Antarctica ice sheet thickness is one of the important information to know the dynamics of changes in the Earth's environment. Geospatial data of the ice sheet surface, land surface and underwater topography, and vertical deformation can be used for ice sheet thickness measurement and calculation. They can be extracted from the latest DTM. The latest DTM is one of the methods and products to extract up-to-date and detailed topography based on the dynamics of the vertical deformation period. This study aims to measure the Antarctica ice sheet thickness based on land surface dynamics and underwater topography from the latest DTM extraction. The vertical accuracy of the DTM, DSM, and vertical deformation uses a 95 % (1.96σ) confidence level. The ice thickness is divided into three types of ice layers according to the reference field: ice thickness above land, ice thickness (above the sea), and ice thickness (underwater). Ice thickness above land has a volume (3,700,299.5 km3), an area (6,767,772 km2), and a total length perimeter (114,569 km). Ice thickness (above the sea) has a volume (28,103,427.8 km3), an area (13,438,789 km2), and a total perimeter length (27,199 km). Ice thickness (underwater) has a volume (1,793,778.6 km3), an area (3,223,036 km2), and a total length perimeter (46,556 km). Antarctica's ice sheet thickness results can be used for various thematic applications of the dynamics of the Earth's environment.

Analysis of Numerical Meteorological Fields due to the Detailed Surface Data in Complex Coastal Area (복잡 연안지역의 지표면 자료 상세화에 따른 수치 기상장 분석)

  • Lee, Hwa-Woon;Jeon, Won-Bae;Lee, Soon-Hwan;Choi, Hyun-Jung
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.6
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    • pp.649-661
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    • 2008
  • The impact of the detailed surface data on regional meteorological fields in complex coastal area is studied using RAMS. Resolutions of topography and land use data are very important to numerical modeling, because high resolution data can reflect correct terrain height and detail characteristics of the surface. Especially, in complex coastal region such as Gwangyang area, southern area in Korean Peninsula, high resolution topography and land use data are indispensable for accurate modeling results. This study investigated the effect of resolutions of terrain data using SRTM with 3 second resolution topography and KLU with 1 second resolution land use data. Case HR was the experiment using high resolution data, whereas Case LR used low resolution data. In Case HR, computed surface temperature was higher than Case LR along the coastline and wind speed was $1{\sim}2m/s$ weaker than Case LR. Time series of temperature and wind speed indicated great agreement with the observation data. Moreover, Case HR indicated outstanding results on statistical analysis such as regression, root mean square error, index of agreement.

Numerical Analysis of Wind Driven Current and Mesoscale Air Flow in Coastal Region with Land Topography (육상지형을 고려한 연안해역에서의 중규모 기상장과 취송류에 관한 수치해석)

  • Lee, Seong-Dae
    • Journal of Ocean Engineering and Technology
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    • v.20 no.5 s.72
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    • pp.23-29
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    • 2006
  • A quasi depth-varying mathematical model for wind-generated circulation in coastal areas, expressed in terms of the depth-averaged horizontal velocity components and free surface elevation was validated and used to understand the diurnal circulation process. The wind velocity is considered as a dominant factor for driving the current. In this paper, three-dimensional numerical experiments that included the land topography were used to investigate the mesoscale air flaw over the coastal regions. The surface temperature of the inland area was determined through a surface heat budget consideration with the inclusion of a layer of vegetation.A series of numerical experiments were then carried out to investigate the diurnal response of the air flaw and wind-generated circulation to various types of surface inhomogeneities.

A Study on The Process of Land-dividing of Urban-Hanok Area in 11 Gahoe-dong, Seoul (서울 가회동11번지 도시한옥주거지의 필지형성과정 연구)

  • Song, Inho;Jung, Kee Hwang
    • Journal of architectural history
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    • v.23 no.5
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    • pp.47-60
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    • 2014
  • Urban-Hanok emerged as a result of urbanization of Hanok in the modern period. In particular, Urban-Hanok has been mass-produced from the early 1920s, when the population is concentrated in cities, until the middle. Large-scale development by the professional developer has been developed in large-scale land rather than individual client because housing shortage was serious problem. 11 Gahoe-dong was made in 1935-36 is representative Urban-hanok area of Bukchon. It was formed through division of large-scale Land in 1930's. In the 1930's, the large-scale development projects of Urban-Hanok was triggered by the two events. One is Land Investigation Project performed by the Japanese government to capitalization of property, another is the pro-japanese bought the large scale-land in Gahoe-dong at bargain price from The Japanese government. Each lot has still a topographical characteristics such as land-dividing quality, the way of development, characteristic quality of urban-tissue. 11 Gahoe-dong, Urban-hanok area was developed two ways. First, development have been adapted to the topography. The lots have reflected topographical conditions such as land cutting area, a retaining wall, land-diving was maintaining the original topography almost. Second, it was street oriented development. The lots have developed sequentially along the street. So, the lots's shape and size is different each. For this reason, this area distribute various type of Hanok.

Land Subsidence Survey and Analysis Using the Terrestrial LIDAR in Jakarta Bay, Indonesia

  • Park, Han-San
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.3
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    • pp.233-240
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    • 2013
  • Jakarta is the capital city of Indonesia which has problems of land subsidence with the rates of about 1 to 15 cm/year, up to 20-25 cm/year. The study has examined the land subsidence in Pantai Mutiara, Jakarta Bay which is a reclaimed area by using the Terrestrial LIDAR survey technique. The Terrestrial LIDAR survey results show that the survey site has mean elevation of 0.24 m with the highest elevation of 0.93 m and lowest - 0.35 m. Considering that AHHW (approximate highest high water) is 0.51 m, many areas of the survey site are lying below the AHHW. Pantai Mutiara area is showing various subsidence rates depending on sites although the site is relatively narrow and small (about 1 $km^2$). There is elevation differences of almost 1m within the site. In this study, key information including topography, dike height distribution, and future coastal flooding risk of the survey area was able to be provided by Terrestrial LIDAR survey conducted only once. Especially, as the 3D precision topography effectively conveys important messages relating to vulnerability of the site, policy makers and stakeholders can easily understand the situation of the site.

Numerical Analysis of Wind Driven Current and Mesoscale Air Flow in Coastal Region with Land Topography (육상지형을 고려한 연안해역에서의 취송류에 관한 수치해석)

  • Lee, Seong-Dae;Kim, In-Ho;Hong, Chang-Bae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1925-1930
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    • 2006
  • A quasi depth-varying mathematical model for wind-generated circulation in coastal areas, expressed in terms of the depth-averaged horizontal velocity components and free surface elevation was validated and used to understand the diurnal circulation process. The wind velocity is considered as a dominant factor for driving the wind generated current. In this paper, three dimensional numerical experiments that included the land topography were used to investigate the mesoscale air flow over the coastal regions. The surface temperature of the inland was determined through the surface heat budget consideration with inclusion of a layer of vegetation. A series of numerical experiments were then carried out to investigate the diurnal response of the air flow and wind-generated circulation to various types of surface inhomogeneities.

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Environmental Friendliness Assessment of Golf Courses in the Capital Region of Korea (수도권 지역 골프장의 환경친화성 평가)

  • 김광두;방광자;강현경
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.5
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    • pp.20-30
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    • 2003
  • This study is aimed at establishing the categories and items for ecological assessment and evaluation of the environmental friendliness of golf courses in the capital region of Korea. The categories and items for the assessment have been derived based on the existing literature and interviews with golf experts. This study covers 32 golf courses in the capital region of Korea that are available in terms of data and on-site surveys. In order to conduct a comprehensive assessment of the environmental friendliness of the golf courses, the assessment area was divided into 4 categories that include a total of 14 sub-categories. The 4 categories encompass 1) location, 2) topography, 3) vegetation, and 4) construction. As its sub-categories, the location category includes current land use and zoning in the National Land Use Management Law. Topography has 2 sub-categories in the damage ratio of existing topography, gradient, cut area, and slope height. The assessment of vegetation is largely based on site surveys in the categories of preservation of the existing vegetation, the use of natural resources and existing trees, the component ratio of native tree species, the multi-layered structure of vegetation, and the utilization of water purification plants. In the aspect of construction, afforestation on tile slopes and the utilization of existing surface soil were evaluated. The examination of comparative analysis among the 10 items as a ratio measure showed that the scores were low in the sub-categories of current land we, the use of existing trees, and the multi-layered structure of vegetation. However, the rating results were satisfactory in the 2 sub-categories including cut area, and the utilization of native tree species. Those proved to be contributing factors in the ecological health of the golf courses. According to correlation analysis of the 10 items to the overall ecological rating of each golf course, the sizes of the 32 golf courses were mainly affected by the damage ratio of existing topography, gradient, preservation of vegetation and slope height. This study has the initiative to conduct an ecological assessment of golf courses in the country based on site surveys. The study results revealed that location factors such as current land use, damage ratio of topography and gradient and topographical factors were the main factors affecting the environmental friendliness of golf courses. This indicates indicating the significance of these factors in the future construction practices of golf courses. Furthermore, this study raises the need for follow-up studies to establish more detailed assessment criteria and to develop assessment techniques for areas such as slope afforestation and water purification plants that need a qualitative approach.

Analysis on the Reliability and Influence Factors of Refraction Traveltime Tomography Depending on Source-receiver Configuration (송수신기 배열에 따른 굴절 주시 역산의 영향 인자 및 신뢰성 분석)

  • Lee, Donguk;Park, Yunhui;Pyun, Sukjoon
    • Geophysics and Geophysical Exploration
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    • v.20 no.3
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    • pp.163-175
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    • 2017
  • In land seismic exploration, irregular surface topography and weathering layer in near surface distorts the reflected signals of data. Therefore, typical land seismic data should be compensated for this distortion by static correction. To perform the static correction, near-surface velocity is required, which can be obtained by seismic refraction survey. However, land seismic data is often acquired in a limited form of geometry depending on the equipment availability, accessibility condition, and permission for the survey site. In this situation, refraction analysis should be performed using reflection data because it is impossible to acquire refraction-oriented data due to limited source and receiver geometry. In this study, we aimed to analyze the reliability of the results obtained by refraction traveltime tomography when using reflection data with a limited number of sources and receivers from irregular surface topography. By comparing the inversion result from irregular topography with that from flat surface, we found that the surface topography affects the reliability of the inversion results to some degree. We also found that the number of sources has little effect on the inversion results unless the number of sources are very small. On the other hand, we observed that velocity distortion occurred in the overlapped part of receiver arrays when using a limited number of receivers, and therefore suggested the size of the least overlapping ratio to avoid the velocity distortion. Finally, we performed numerical tests for the model which simulates the surface topography and acquisition geometry of the survey region and verified the reliability analysis of inversion results. We identified reliable areas and suspicious area of the inverted velocity model by applying the analysis results to field data.