• Title/Summary/Keyword: topographical analysis

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Analysis of the Location Environment of the Sub-alpine Coniferous Forest in National Parks Using GIS - Focusing on Abies koreana - (GIS를 활용한 국립공원 아고산대 침엽수림의 입지환경 분석 - 구상나무를 대상으로 -)

  • Kim, Tae-Geun;Oh, Jang-Geun
    • Korean Journal of Ecology and Environment
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    • v.49 no.3
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    • pp.236-243
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    • 2016
  • It was a case study to use as a basic data for efficient the preservation and management of subalpine coniferous forest in national parks. It is based on inhabitation condition of 210 individuals of Abies koreana Wilson that was found through local investigation in the sub-alpine zone of Jirisan National Park and Songnisan National Park. It analyzed the effect of the geographical location and topographical features, which are the basics of location environment, on the growth of A. koreana. The variables related to the growth of A. koreana are tree height and diameter at breast height. Topographical features include geographical longitude, altitude above sea level, slope of the mountains, aspect that describes the direction in which a slope faces and topographical wetness index. Topographical features were extracted through GIS spatial analysis. It used canonical correlation analysis to estimate whether the two variables groups have related to each other and how much they are related, if any, and estimated the effect of the geographical and topographical features on the growth structure of A. koreana using multiple regression analysis. The tree height and diameter at breast height that represent the growth structure of A. koreana show greater relation to geographical latitude distribution than topographical feature and the geographical and topographical factors show greater relation to diameter at breast height than tree height. The growth structure's variable and geographical and topographical variable of A. koreana have meaningful relation and the result shows that geographical and topographical variables explain 18.1% of the growth structure. The variables that affect the diameter at breast height of A. koreana are geographical latitude, topographical wetness index, aspect and altitude, which are put in order of statistical significance. The higher the latitude is, the smaller the diameter at breast height. Depending on the topographical feature, it becomes bigger. The variable that affects the tree height is topographical wetness index, which was the only meaningful variable. Overall, the tree height and diameter at breast height that are related to the growth structure of A. koreana are affected by geographical and topographical feature. It showed that the geographical feature affected it the most. Especially the effect of water among the topographical features is expected to be bigger than the other topographical factors. Based on the result, it is expected that geographical and topographical feature is an important factor for the growth structure of A. koreana. Even though it considered only the geographical and topographical features and used spatial analysis data produced by GIS, the research results will be useful for investigating and researching the growth environment of coniferous forest inhabiting in sub-alpine zone of national parks and are expected to be used as basic data for establishing measures to efficiently manage and preserve evergreen needleaf tree such as A. koreana.

Terrestrial LiDAR Measurements and Analysis of Topographical Changes on Malipo Beach (지상 LiDAR를 이용한 만리포 해변 정밀 지형측량 및 지형 변화 분석)

  • Shim, Jae-Seol;Kim, Jin-Ah;Park, Han-San;Kim, Seon-Jeong
    • Ocean and Polar Research
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    • v.32 no.1
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    • pp.73-84
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    • 2010
  • A terrestrial LiDAR was used to acquire precise and high-resolution topographical information of Malipo beach, Korea. Terrestrial LiDAR and RTK-DGPS (VRS) were mounted on top of a survey vehicle and used to scan 20 times stop-and-go method with 250 m spacing intervals at ebb tides. In total, 7 measurements were made periodically from 2008 to 2009 and after each beach replenishment event. We carried out GIS-based 3D spatial analysis such as slope and volume calculations in order to assess topographical changes over time. In relation to beach replenishment, comparative analysis of each volume change revealed them to be similar. This result indicates that the terrestrial LiDAR measurements are accurate and can be used to analyze temporal topographical changes. In conclusion, the methodology employed in this study can be used efficiently to exercise coastal management through monitoring and analyzing beach process such as erosion and deposition.

Change characteristic of basin topographical parameters according to the threshold area of minimum order stream (최소차 하천의 임계면적에 따른 유역 지형매개변수의 변화특성)

  • Ahn Seung-Seop;Park Ro-Sam;Kim Jong-Ho;Lim Ki-Seok;Song Si-Hoon
    • Journal of Environmental Science International
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    • v.14 no.1
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    • pp.33-40
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    • 2005
  • The size of minimum order stream has a very sensitive effect on runoff analysis model using the divergence characteristic of stream. Therefore, in this study, the threshold area of minimum order stream has been examined the change characteristic of topographical parameters. The subject basin of the research was the upper basin of the Kumho water gage station which is located in the middle of the Kumho river. The 1:25,000 numerical geography which was constructed $10{\times}10m$ mesh was used. The range of investigation of topographical parameters are number of stream order, length, area, slope, basin relief, sinuosity ratio, drainage density and total stream length etc. It was found from the result of analysis that the threshold value of minimum order stream has a very big effect on topographical parameters of basin. It was found that the threshold area of minimum ord er stream revealed under $0.10km^{2}.$ Furthermore, the parameters showed a serious change except for over $0.10km^{2}.$

An Experimental Study on the Construction of Administrative Boundaries Using Old Topographical Map in the 1910s (1910년대 고 지형도를 이용한 행정리 경계 구축에 관한 실험적 연구)

  • Eom, Seong-Jun;Cho, Suk-Yeong;You, Soo-Jin;An, Phil-Gyun
    • Journal of the Korean Institute of Rural Architecture
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    • v.23 no.2
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    • pp.45-54
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    • 2021
  • This study aims to establish administrative boundaries by utilizing digitalized old topographical map. Various problems have arisen due to unclear administrative boundaries. For example, there are various problems such as conflict amongst residents to occupy a larger area, unnecessary waste of administrative power, and difficulty in collecting various data for administrative units (farm area, statistical data, spatial analysis, living ara analysis). Therefore, in this study, an experimental study was conducted to establish administrative boundaries by using an old topographical map containing information on villages before administrative reform in 1914. As a result, the boundaries of towns, towns and villages were largely consistent. In order to divide the administrative boundaries based on the legal district boundaries, the administrative boundaries were established by referring to the contents of village introduction and natural boundaries (roads, rivers, mountain ranges, etc.) provided in towns and villages. However, there was a limit in establishing a precise boundary as it was not possible to secure a high-quality digitalized old topographical map.

Web-based GIS for Real Time Hydrologic Topographical Data Extraction for the Geum River Watershed in Korea (Web기반 GIS를 이용한 금강유역의 실시간 수문지형인자 추출)

  • Nam, Won-Ho;Choi, Jin-Yong;Jang, Min-Won;Engel, B.A.
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.5
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    • pp.81-90
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    • 2007
  • Watershed topographical information is required in hydrologic analysis, supporting efficient hydrologic model operation and managing water resources. Watershed topographical data extraction systems based on desktop GIS are abundant these days placing burdens for spatial data processing on users. This paper describes development of a Web-based Geographic Information Systems that can delineate the Geum River sub-basins and extract watershed topographical data in real time. Through this system, users can obtain a watershed boundary by selecting outlet location and then extracting topographical data including watershed area, boundary length, average altitude, slope distribution about the elevation range with Web browsers. Moreover, the system provides watershed hydrological data including land use, soil types, soil drainage conditions, and NRCS(Natural Resources Conservation Service) curve number for hydrologic model operation through grid overlay technique. The system operability was evaluated with the hydrological data of WAMIS(Water Management Information System) with the government operation Web site as reference data.

Application Study on the View Points Analysis for National Roads Route using Digital Elevation Data

  • Yeon, Sang-Ho;Hong, Ill-Hwa
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.292-296
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    • 2002
  • This study has been accomplished as a experimental study for field application of 3D Perspective Image Map creation using Digital Topographical Map and based on the Ortho-Projection Image which is generated from Satellite Overlay Images and the precise Relative Coordinates of longitude, latitude and altitude which is corrected by GCP(Ground Control Point). AS to Contour Lines Map which is created by Coordinate conversion of 1:5,000 Topographical Map, we firstly made Satellite Image Map to substitute for Digital Topographical Map through overlapping the original images on top of each Ortho-Projection Image created and checking the accuracy. In addition to 3D Image Map creation for 3D Terrain analysis of a target district, Slope Gradient Analysis, Aspect Analysis and Terrain Elevation Model generation, multidirectional 3D Image generation by DEM can be carried out through this study. This study is to develop a mapping technology with which we can generate 3D Satellite Images of a target district through the composition of Digital Maps and Facility Blueprint and arbitrarily create 3D Perspective Images of the target district from any view point.

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Development of Web-GIS based SWAT Data Generation System (Web-GIS 기반 SWAT 자료 공급 시스템 구축)

  • Nam, Won-Ho;Choi, Jin-Yong;Hong, Eun-Mi;Kim, Hak-Kwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.6
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    • pp.1-9
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    • 2009
  • Watershed topographical data is essential for the management for water resources and watershed management in terms of hydrology analysis. Collecting watershed topographical and meteorological data is the first step for simulating hydrological models and calculating hydrological components. This study describes a specialized Web-based Geographic Information Systems, Soil Water Assessment Tool model data generation system, which was developed to support SWAT model operation using Web-GIS capability for map browsing, online watershed delineation and topographical and meteorological data extraction. This system tested its operability extracting watershed topographical and meteorological data in real time and the extracted spatial and weather data were seamlessly imported to ArcSWAT system demonstrating its usability. The Web-GIS would be useful to users who are willing to operate SWAT models for the various watershed management purposes in terms of spatial and weather preparing.

A FORECASTING METHOD FOR FOREST FIRES BASED ON THE TOPOGRAPHICAL CLASSIFICATION SYSTEM AND SPREADING SPEED OF FIRE

  • Koizumi, Toshio
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.311-318
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    • 1997
  • On April 27,1993, a forest fire occurred in Morito-area, Manba-city, Gunma-prefecture Japan. Under the prevailing strong winds, the fire spread and extended to the largest scale ever in Gunma-prefecture. The author chartered a helicopter on May 5, one week after the fire was extinguished, and took aerial photos of tile damaged area, and investigated the condition. of the fire through field survey and data collection. The burnt area extended. over about 100 hectares, and the damage amounted to about 190 million yen (about two million dollar). The fire occurred at a steep mountainous area and under strong winds, therefore, md and topography strongly facilitated the spreading, It is the purpose of this paper to report a damage investigation of the fire and to develop the forecasting method of forest fires based on the topographical analysis and spreading speed of fire. In the first place, I analyze the topographical structure of the regions which became the bject of this study with some topographical factors, and construct a land form classification ap. Secondly, I decide the dangerous condition of each region in the land form classification map according to the direction of the wind and spreading speed of f'kre. In the present paper, I try to forecast forest fires in Morito area, and the basic results for the forecasting method of forest fires were obtained with the topographical classification system and spreading speed of fire.

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Determination of Grid Size to Extract Hydrologic -Topographical Parameters (수문지형인자 추출에 따른 격자크기의 결정)

  • Jeong, In-Ju;Seo, Kyu-Woo;Kim, Ga-Ya
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.3
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    • pp.23-33
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    • 2005
  • Hydrologic-topographical parameters were extracted using GIS. The use of GIS is more effective and exact than the execution by person. And the purpose of this paper is to extract more efficient size of grid for DEM analysis by applying GIS technology. As a result, when the grid size is less than $100m{\times}100m$ the trend of extracted parameters is similar but when the grid size is over $100m{\times}100m$ the trend of extraction parameters is dispersive. Therefore, it is appropriate to extract hydrologic-topographical parameters the grid size of $100m{\times}100m$ in DEM analysis.

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A Study on Development and Utilization of Wind Hazard Maps (강풍위해지도 개발 및 활용 방안에 관한 연구)

  • Lee, Young-Kyu;Lee, Sung-Su;Ham, Hee-Jung
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.1-8
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    • 2011
  • In this study, a wind hazard map over Korea peninsula based on geographical information is developed, which consists of the surface roughness model, the topographical effect model and the homogeneous wind model. The surface roughness model is assessed to evaluate the effect of the surface roughness on the wind field near ground. The topographical effect model is assessed to quantify the effect of the speed-up caused by topology, which is calculated by adopting the topographical effect factor in Korea building code (2005). The homogeneous wind map is created either by a frequency analysis method for meteorological data or a typhoon simulation. The results show that the wind hazard map can be applied to the determination of insurance premium as well as the assessment of loss and damage.