• Title/Summary/Keyword: topographical survey

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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.

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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Spatial-temporal Analysis of Topographical Change at the Malipo Beach (만리포 사빈의 시계열 3차원 지형 변화 분석)

  • PARK, Han San
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.1
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    • pp.97-109
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    • 2013
  • This study introduces an analysis of the quantitative characteristics of topography and topographical changes based on precise 3D topography through 6 times surveys from December 2008 to January 2010 using Terrestrial LIDAR on the Malipo beach. The Malipo sand beach is mostly located between 0m to 1.5m MSL. The area of the beach above 2.25m, the Mean High Water, is very small. It have characteristics of topographical change of erosion and deposition along the entire coast line which more apparently appear in the northern beach than the southern part of the beach. Erosion prevails from spring to autumn, while during winter both erosion and deposition largely occur. Volumes from first and last survey were almost equal.

The Optimal Locational Environment of the Bronze Age Settlement in Cheonan Baekseok-dong through the Ridge Environment's Perspective - Focusing on the Locational Characteristics of Residential Areas Based on Geographical Analysis and GIS Analysis - (능선환경으로 본 천안 백석동 청동기시대 취락의 최적 입지환경 - 지형분석과 GIS분석을 이용한 주거지 입지 특성에 주목하여 -)

  • Park, Ji Hoon;Lee, Ae Jin
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.4
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    • pp.103-116
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    • 2018
  • The purposes of this research are as follows: First, to reconstruct the optimal locational environment of the Bronze Age settlement in Cheonan Baekseok-dong (hereinafter referred to as the study settlement). Second, to identify the priority ranking of the topographical factors that influenced the Bronze Age people when selecting their the settlement location. For these reasons, the topographical factors of the 200 Bronze Age dwellings (hereinafter referred to as dwellings) confirmed in the survey area were analyzed through the ridge's environmental perspective. The results are asfollows: First, the optimal ridge environment of the Bronze Age settlement is largely a sub-ridge in N-S direction (for example, NNW-SSE, N-S, NNESSW), especially at the top (Crest slope, Crest flat) of the south-facing aspect of the ridge. Second, when the Bronze Age dwellers selected a residential location, they carefully considered topographical factors in the following order: (1) the slope direction of the ridge surface, (2) the micro-landform of the ridge, (3) the ridge scale, (4) the ridge direction, and (5) the surface relief. The results of this study could be used as basic data in related fields such as archaeology, quaternary research, and traditional architecture and so on.

The Optimal Location Environment of the Bronze Age Settlement in Yongdu Stream and its Surrounding Area in Asan through the Ridge Environment's Perspective (능선환경으로 본 아산 용두천 유역 및 주변 지역에 있어서 청동기시대 취락의 최적 입지환경)

  • Park, Ji Hoon;Lee, Ae Jin
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.4
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    • pp.89-112
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    • 2020
  • The purpose of this study is as follows: First, we restore the optimal topographical environment of the Bronze Age settlements in the Yongdu Stream and its surrounding area in Asan City. Second, we reveal the relative importance of the topographical factors that the Bronze Age people considered when selecting their dwelling locations. We compared and analyzed topographical factors (ridge scale, ridge direction, slope direction of the ridge, micro-landform of the ridge, position of the ridge) from the ridge's environmental perspective of 123 Bronze Age dwellings (hereinafter referred to as dwellings) found in the survey area for that purpose. The results are as follows: First, from a macro perspective, the optimal topographical environment for the location of the Bronze Age settlement is the second ridge that have the E-W direction. And from a micro perspective, it is the southeast direction slope of the Crest slope at the summit. Second, it appears that the Bronze Age people have taken important consideration in determining the location of their dwelling in the following order: ① position (eg. summit), ② micro-landform (eg. Crest slope, Upper slope), ③ slope direction (eg. southward, South, Southeast), ④ scale (eg. sub-ridge, secondary, tertiary), ⑤ direction (eg. E-W, NNE-SSE).

The Modification of Serial Cadastral Map and Its Applications to Notification of Topographical Maps (연속지적도면의 정비와 지형도면고시에 활용 방안)

  • Hong, Sung-Eon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.11
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    • pp.4826-4834
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    • 2011
  • This study examined the method of making high-quality serial cadastral map with field surveying, the renewal and applications of serial cadastral map which is made for the application of notification of various topographical maps, and related legal and institutional contents. The results of the study are as follows. First, we suggested the way of modification that enables preexisting methods to connect with field surveying in order to improve utilizability of serial cadastral map that is not utilized properly. In addition, we came up with legal grounds from a current law, 'act on surveying watercourses survey and cadastre' for the modification. We also examined legal and institutional factors, the renewal and application of various notifications of topographical maps for efficient application, and the application of modified serial cadastral map for field surveying. Once the current cadastral map is modified based on the results of our study, it is possible that notification of topographical maps gets more accurate, and serial cadastral map can be used for field surveying. In addition, the modification can be utilized for a step-by-step strategy that reduces the existing cadastral map managed as 3 types into the cadastral map managed as 1 type.

Application Technique of Geospatial Information for Pre-Environment Survey in Construction Site (건설현장 사전 환경조사를 위한 공간정보의 적용기법)

  • Yeon, Sang-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.1
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    • pp.119-128
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    • 2014
  • The environmental survey in advance in the construction works is very important for planning and designing as well as the service of field survey before carrying out construction. The topographical application of spatial information coupled with USN is the very economical method for the survey and research every processing stage of construction field in advance. Therefore the execution of very important role for environmental planning and fundamental designing of construction reduces the unnecessary trial and error through the environmental survey in advance. In this research the environment of existent construction field is transformed to that of digital spatial information by fusing the sensor network with wireless technique on the base of spatial position. In addition, the sink sensor cumulates the environmental data measured from each USN sensor using small wireless environmental sensors installed at the construction site and changes of various environmental data at the present constructing site are able to be monitored at 3-D topographical space in real time by using the method for transmitting the image of PC output based on TinyOS.

Flow characteristics of Geumo Islands Sea area by numerical model experiments (수치실험을 통한 금오열도 해역의 해수유동 특성)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.2
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    • pp.159-174
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    • 2022
  • Flow prediction was carried out through observational survey and three dimensional multi-layered numerical diagnostic model experiment to clarify the time and spatial structure of tidal current and residual flow dominant in the sea exchange and material circulation of the waters around Geumo Islands in the southern waters of Korea. The horizontal variation of tidal current is so large that it causes asymmetric tidal mixing due to horizontal eddies and the topographical effect creating convergence and dispersion of flow direction and velocity. Due to strong tidal currents flowing northwest-southeast, counterclockwise and clockwise eddies are formed on the left and right sides of the south of Sori Island. These topographical eddies are created by horizontal turbulence and bottom friction causing nonlinear effects. Baroclinic density flows are less than 5 cm/s at coastal area in summer and the entire sea area in winter. The wind driven currents assuming summer and winter seasonal winds are also less than 5 cm/s and the current flow rate is high in winter. Density current in summer and wind driven current in winter have a relatively greater effect on the net residual flows (tidal residual current + density current + density driven current) around Geumo Islands Sea area.

Introduction of Hydraulic Field Investigation Method to Utilize on the Inhabitation Environment Definition at a River

  • Lee, Hyun-Seok;Kim, Young-Sung;Lee, Geun-Sang;Seo, Jin-Won;Yang, Jae-Rheen;Kwon, Hyung-Joong
    • Korean Journal of Ecology and Environment
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    • v.41 no.4
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    • pp.547-553
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    • 2008
  • In recent years, attention on the inhabitation environments of animals and plants which coexist with humans is growing more and more, and relevant research is being activated. In habitats of rivers, a lot of factors are interacting, even among them, some elements especially such hydraulic factors as water velocity and water depth, and such geological shapes as gravels, sand and mud are being considered as primary elements. In this study, various field investigations are carried out to determine the relationship between the river habitats of fishes and hydraulic primary elements using high-tech equipments. Furthermore numerical experiments to classify such habitats according to topographical spaces are carried out. In detail, hydraulic field investigations performed in this study can be summarized as topographical survey, discharge measurement, water level fluctuation monitoring and so on. In numerical experiments, the RMA2 model of the commercial program, Surface-Water Modeling System (SMS), which is widely used in conducting a two-dimensional analysis of the flow behavior of a river is utilized. In conclusion, as a result of field investigation, the relationship between water velocity and water depth is obtained. And the relationship between water velocity and water temperature is identified, too. Finally, using above obtained results, the inhabitation environment was classified into Riffle, Glide, Run, Pool, and E.D.Z according to the relationship between water velocity and water depth.