• Title/Summary/Keyword: Topographic characteristics

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Investigation of Topographic Characteristics of Parcels Using UAV and Machine Learning

  • Lee, Chang Han;Hong, Il Young
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.5
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    • pp.349-356
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    • 2017
  • In this study, we propose a method to investigate topographic characteristics by applying machine learning which is an artificial intelligence analysis method based on the spatial data constructed using UAV and the training data created through spatial analysis. This method provides an alternative to the subjective judgment and accuracy of spatial data, which is a problem of existing topographic characteristics survey for officially assessed land price. The analysis method of this study is expected to improve the problems of topographic characteristics survey method of existing field researchers and contribute to more accurate decision of officially assessed land price by providing more objective land survey method.

The Study of Physiographic province in Korea (한국지형구(韓國地形區))

  • Park, No-Sik
    • Journal of the Speleological Society of Korea
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    • no.68
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    • pp.75-98
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    • 2005
  • Korea physiographic province is divided into two provinces which is northern Chugaryung graben zone and southern Chugraryung graben zone. Northern Chugraryung is also divided in to Gema block and Kohan block, and southern Chugraryung dividedinto Han block, Yongnam basin and Honam plain. The above mentioned macro geomorophic units is divided, mainly on the geotectonics. The meso geomorphic units is divided, based upon the regional distribution of topographic characteristic that is plateaus, mountains, mountain range, basins and great plain etc. Micro geomorphic units id into a mountain, a hill, a plain, and a lowland, and then it is formed by selfreliant topographic unit. And micro topographic (fan, peneplain, delta, etc) dealt with a characteristics unit. In this article has a disregarded amallest scale that is included flood plait natural levee, back marsh and oxbow lake etc. Accordingly, it shows macro units are meso units are 5, meso units are 53, micro units are 299. A study method of physiographic provincs prefered to aufsteigende and abstergands methoy. How to organically combine topographic factors can be seen in regional distribution of the peculiar topographic characteristics, for charage teristic of topographic makes a study on the topographic of micro unit such understanding as aufsteigende method. At the same time, since it can be studied systematically from marco unit to micro unit like the absteigende methods, I used both methods. And this establishment of physiographic province based on the scientific method depend on the base map of climate classification. Geology, Soil, Biology. I feel confident that it will be used the basic map for land use map, land classification map, study of geomorphology of Korea. And will be used for study of a topographic standard data.

Development of Hill Housing Addatable to the Topographic Characteristics on Sloping Sites (경사지의 지형특성에 적합한 경사지주택 개발 계획)

  • Hyun, Taek-Soo
    • Journal of the Korean Institute of Rural Architecture
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    • v.14 no.1
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    • pp.57-66
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    • 2012
  • This study focuses on the applicability of hill housing design in accordance with topographic characteristics on sloping sites. The urgency for housing still exists but hill sites have to be planned by gradual development using 'all available land' within any particular community. However, there is a reaction towards being more closely involved with nature and landscape. Sloping and hill sites must be developed by intelligent and sensitive planning, integrating the existing environmental factors. The results of this study are as follows : 1. The conditions of location are regarded as the concepts of spactial configuration. It should be developed on the basis of awareness that nature and human beings exist together. 2. It is inevitable that the development of the hill housing should be performed prefer to the topographic characteristics. 3. Planning elements of ecological residental blocks which are possible for constructing on the hill site can be developed and applied, on the basis of geographical characteristics, by housing types.

Field measurements of wind characteristics over hilly terrain within surface layer

  • He, Y.C.;Chan, P.W.;Li, Q.S.
    • Wind and Structures
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    • v.19 no.5
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    • pp.541-563
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    • 2014
  • This paper investigates the topographic effects on wind characteristics over hilly terrain, based on wind data recorded at a number of meteorological stations in or near complex terrain. The multiply data sources allow a more detailed investigation of the flow field than is normally possible. Vertical profiles of mean and turbulent wind components from a Sodar profiler were presented and then modeled as functions of height and wind speed. The correlations between longitudinal and vertical wind components were discussed. The phenomena of flow separation and generation of vortices were observed. The distance-dependence of the topographic effects on gust factors was revealed subsequently. Furthermore, the canyon effect was identified and discussed based on the observations of wind at a saddle point between two mountain peaks. This study aims to further understanding of the characteristics of surface wind over rugged terrain. The presented results are expected to be useful for structural design, prevention of pollutant dispersion, and validation of CFD (computational fluid dynamics) models or techniques over complex terrains.

ROC Analysis of Topographic Factors in Flood Vulnerable Area considering Surface Runoff Characteristics (지표 유출 특성을 고려한 홍수취약지역 지형학적 인자의 ROC 분석)

  • Lee, Jae Yeong;Kim, Ji-Sung
    • Ecology and Resilient Infrastructure
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    • v.7 no.4
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    • pp.327-335
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    • 2020
  • The method of selecting an existing flood hazard area via a numerical model requires considerable time and effort. In this regard, this study proposes a method for selecting flood vulnerable areas through topographic analysis based on a surface runoff mechanism to reduce the time and effort required. Flood vulnerable areas based on runoff mechanisms refer to those areas that are advantageous in terms of the flow accumulation characteristics of rainfall-runoff water at the surface, and they generally include lowlands, mild slopes, and rivers. For the analysis, a digital topographic map of the target area (Seoul) was employed. In addition, in the topographic analysis, eight topographic factors were considered, namely, the elevation, slope, profile and plan curvature, topographic wetness index (TWI), stream power index, and the distances from rivers and manholes. Moreover, receiver operating characteristic analysis was conducted between the topographic factors and actual inundation trace data. The results revealed that four topographic factors, namely, elevation, slope, TWI, and distance from manholes, explained the flooded area well. Thus, when a flood vulnerable area is selected, the prioritization method for various factors as proposed in this study can simplify the topographical analytical factors that contribute to flooding.

Solution Approaches to Multiple Viewpoint Problems: Comparative Analysis using Topographic Features (다중가시점 문제해결을 위한 접근방법: 지형요소를 이용한 비교 분석을 중심으로)

  • Kim, Young-Hoon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.3
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    • pp.84-95
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    • 2005
  • This paper presents solution heuristics to solving optimal multiple-viewpoint location problems that are based on topographic features. The visibility problem is to maximise the viewshed area for a set of viewpoints on digital elevation models (DEM). For this analysis, five areas are selected, and fundamental topographic features (peak, pass, and pit) are extracted from the DEMs of the study areas. To solve the visibility problem, at first, solution approaches based on the characteristics of the topographic features are explored, and then, a benchmark test is undertaken that solution performances of the solution methods, such as computing times, and visible area sizes, are compared with the performances of traditional spatial heuristics. The feasibility of the solution methods, then, are discussed with the benchmark test results. From the analysis, this paper can conclude that fundamental topographic features based solution methods suggest a new sight of visibility analysis approach which did not discuss in traditional algorithmic approaches. Finally, further research avenues are suggested such as exploring more sophisticated selection process of topographic features related to visibility analysis, exploiting systematic methods to extract topographic features, and robust spatial analytical techniques and optimization techniques that enable to use the topographic features effectively.

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Estimating Method of Topographic Factor of Design Wind Speed Using GIS (GIS를 이용한 지형에 의한 풍속할증계수 산정 방법)

  • Choi, Se-Hyu;Seo, Eun-Su
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.3
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    • pp.126-135
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    • 2013
  • With more than 70% of the country consisting of mountains, Korea has large and small mountains, and hills located in the inner cities. Therefore, Korea's architectural structure laws stipulate that an increase in wind speed due to the influence of terrain should be considered in the design of wind loads of buildings. But if more than two mountains are located around the building or if the boundaries of the land surface are not clear when calculating topographic factors of wind speed, the designer has subjectively selected the coverage of the topographic factors of wind speed or the surface. This may lead to unscientific design of wind loads. This study attempts to analyze topographic factors of wind speed by using a 1:5000 topographic map with relatively high location accuracy and thereby to reflect changes due to the topographic characteristics and influence at the point where the building is located. By also selecting terrain surfaces and vertexes through Arc GIS and presenting a scientific approach to determine the range of topographic factors of wind speed, this study is expected to make a contribution for more rational and cost-effective wind-resistant design of buildings.

A Study on the Land Cover Characteristics in Korea : Application of Hybrid Classifier and Topographic Normalization

  • Jeon, Seong-Woo;Jung, Hui-Cheul;Chung, Sung-Moon;Lee, Sang-Ik
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.271-280
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    • 1999
  • The topographical effect resulted from rugged terrains and inhomogeneous spectral characteristics due to the complexly mixed land cover condition of Korea substantially lower the remotely sensed land cover classification accuracy In this study, a topographic correction method using digital elevation model to alleviate the topographic effects. To deal with inhomogeneous spectral characteristic, a hybrid classifier with inclusion of prior probabilities was introduced. This investigation concluded that the topographical normalization and hybrid classification with prior probabilities are effective on rugged landscape. The overall and average classification accuracies were improved by 0.92% and 1.016% respectively. The most substantial and noticeable accuracy improvement was observed in forest areas.

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Topographic Monitoring over Land Surface using Radar Altimeter

  • Kim, Yong-Hoon
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.174-179
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    • 1998
  • In this paper, the radar altimeter for topographic mapping over land is introduced and the characteristics of the return signals are analyzed. The radar system is described briefly and the requirements to get the fine resolution of the terrain surface height are considered. The designed radar altimeter was tested on the landscape in the near of Stuttgart. The measured data shows very fine profile of the test landscape and the height errors induced from different geometrical structure of the land surface are acquired in the measurement. In the test area, most characteristics of radar return signals over land could be tested and the results of the topographic mapping using our radar altimeter can be used for future radar altimeter development for land applications.

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Analysis of Stream Physiographic Characteristics of River Basin by using GIS (지리정보시스템을 이용한 하천유역의 지상학적 특성분석)

  • Ahn, Seung-Seop;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.3
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    • pp.23-34
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    • 1999
  • This study proposed the possibility of GIS to analyze stream physiographic characteristics of river basin which is important control factor in complex water management. Based on five 1:25,000 topographic maps which cover Yengchon Dam area locates upper area of Kumho River, this study analyzed the characteristics using Arc/Info(UNIX) GIS. Comparing its results and those from the existing method using digital planimeter, it could conclude as follows; First, as the results of the analysis of hypsometric curve of Yeungchon Dam area, it has the topographic characteristics of youth and maturity. And the landform of Yengchon Dam area has developed with regularity when Horton's three laws on the morphology of stream is applied. Second, the possibility of applying GIS to data management and utilization is sufficient even if it requires long time to construct topographic attribute data. Finally, a further research is needed on watershed direction with landform for the purpose of analyzing water source management and topographic property effectively.

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