• Title/Summary/Keyword: terrain change

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Urban Building Change Detection Using nDSM and Road Extraction (nDSM 및 도로망 추출 기법을 적용한 도심지 건물 변화탐지)

  • Jang, Yeong Jae;Oh, Jae Hong;Lee, Chang No
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.3
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    • pp.237-246
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    • 2020
  • Recently, as high resolution satellites data have been serviced, frequent DSM (Digital Surface Model) generation over urban areas has been possible. In addition, it is possible to detect changes using a high-resolution DSM at building level such that various methods of building change detection using DSM have been studied. In order to detect building changes using DSM, we need to generate a DSM using a stereo satellite image. The change detection method using D-DSM (Differential DSM) uses the elevation difference between two DSMs of different dates. The D-DSM method has difficulty in applying a precise vertical threshold, because between the two DSMs may have elevation errors. In this study, we focus on the urban structure change detection using D-nDSM (Differential nDSM) based on nDSM (Normalized DSM) that expresses only the height of the structures or buildings without terrain elevation. In addition, we attempted to reduce noise using a morphological filtering. Also, in order to improve the roadside buildings extraction precision, we exploited the urban road network extraction from nDSM. Experiments were conducted for high-resolution stereo satellite images of two periods. The experimental results were compared for D-DSM, D-nDSM, and D-nDSM with road extraction methods. The D-DSM method showed the accuracy of about 30% to 55% depending on the vertical threshold and the D-nDSM approaches achieved 59% and 77.9% without and with the morphological filtering, respectively. Finally, the D-nDSM with the road extraction method showed 87.2% of change detection accuracy.

Change Monitoring in Ecological Restoration Area of Open-Pit Mine Using Drone Photogrammetry (드론사진측량을 이용한 노천광산 생태복원지역의 변화 모니터링)

  • Lee, Dong Gook;Yu, Young Geol;Ru, Ji Ho;Lee, Hyun Jik
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.4
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    • pp.97-104
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    • 2016
  • In this study, analyze and monitor the change of the ecological restoration area inside the open-pit mine in Gangwon-do. and to analyze and monitor the change of ecological restoration area. analyzed the distribution of vegetation using high-resolution orthophoto of various periods and analyzed terrain change using DSM/DEM in study area. Therefore, orthophoto and 포인트 클라우드 were collected from 2014 aerial laser surveying and 2015 fixed-wing drone photogrammetry. In addition, orhtophoto and 포인트 클라우드 were produced by using rotary-wing drone photogrammety in 2016, and change of ecological restoration area was analyzed using this. As a result, it's possible to perform change monitoring of the open-pit mine ecological restoration area. using nEGI and VARI, about 10-30% of the area ratio of the result of extracting vegetation distribution area is distributed, and the comparison DSM and DEM cross section and restoration plan line, the cross section made by using the drone were similar, and the earth-volume analysis was possible.

Cause and Process of Place-Name Change by Social Influence : A Case Study of Jin-An Region (사회적 영향에 의한 지명 변화의 원인과 과정 -전북 진안군 지명을 사례로-)

  • Cho, Sung-Wook
    • Journal of the Korean association of regional geographers
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    • v.13 no.5
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    • pp.526-542
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    • 2007
  • This study look into the place-name change by social influence around Jin-An region. The place-names were made through joining natural environment with social condition. The place-names were born as a river name firstly, and it was selected as the artificial administration district name in this region(Ju-Chon, Jeong-Chon, An-Chon). Generally the place-name is reflected by a terrain feature of narrow area but this region's place name was made by wide river drainage area as a system. It is different point to others place-name and the social factor played more important role than natural environment in this process. The displacement process of mountain name which is from Ju-Jul to Un-Jang was through social situation change without the natural conditions change. It was used to the Ju-Jul firstly and coexistent the Ju-Jul with Un-Jang and only use the Un-Jang recently. Formal change period was 1910s in the map, Mt. Un-Jang(雲長山) had the advantage at the pronunciation and written than Mt. Ju-Jul. Mt. Gu-Bong(九峰山) was played important role for new mountain name and Song Ik-Pil(宋翼弼) was appeared for rationalization of Mt. Un-Jang.

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Study of Correlation Between Flash Flood and GcIUH Parameters using GIS (GIS를 이용한 한계유량과 GcIUH 매개변수간의 상관성분석에 관한 연구)

  • Yang, In Tae;Park, Kheun
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.4
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    • pp.37-44
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    • 2013
  • Concentrated localized torrential rains due to global warming and climate change have resulted in much water damage each year. GIS is used as a tool for predicting the peak-outflows caused by these regional torrential rains in mountainous rivers. However, the research of the resolution of the data is limited, and most of approaches are about hydrological geographic. This paper estimates the flood discharge needed for decision of standard rainfall of automatic rainfall warning system by using GIS with GcIUH model, and establishes the criteria of flash flood warning. It also has analyzed the terrain in river basin, extracted the morphological characteristics parameters of water shed such as stream width, channel slope, channel length, shape factor, and GcIUH parameters, and analyzed the relationship between them.

A Study on the Wildland Fire Total Hazard Classification (산림화재 종합위험등급화에 관한 연구)

  • 김동현;김태구;김광일
    • Fire Science and Engineering
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    • v.15 no.3
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    • pp.49-54
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    • 2001
  • Recently, intentional arsons for exploitation and wildland fire caused by abnormal change of weather are increasing as well as the damage scale due to such fire in the world. The number of such big wildland fire is also increasing in Korea these days. Fire prevention activity can be said as more important than fire putting-out activity after a fire occurrence for the most effective way to cope with wildland fire, and the research on wildland fire prevention system is what we need to do urgently, In this study I examined and analyzed the experiments and data about the factors influencing wildland fire and stated the dangerousness of each factor for all of the 6 factors and set up the general dangerousness rating applying each factor's contribution to the dangerousness.

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Change of TC Activity Around Korea by Arctic Oscillation Phase (북극진동의 위상에 따른 한국 부근에서의 태풍 활동 변화)

  • Choi, Ki-Seon;Kim, Tae-Ryong
    • Atmosphere
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    • v.20 no.4
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    • pp.387-398
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    • 2010
  • This study shows that frequency of tropical cyclone (TC) around Korea in summer (June-September) has positive relation with Arctic Oscillation (AO) in the preceding April. In a positive AO phase, each of anomalous cyclone and anomalous anticyclone is developed in low latitude and middle latitude regions of East Asia from the preceding April to summer. As a result, while anomalous southeasterly around Korea serves as a steering flow that TCs move toward this area is strengthened, northwesterly that reinforced in southeastern area of East Asia plays a role in preventing TCs from moving toward this area. In addition, due to this distribution of pressure systems developed in this AO phase, TCs tend to occur, move and recurve in further northeastern region in the western North Pacific than TCs in a negative AO phase. On the contrary, TCs in a negative AO phase mainly move westward toward southern China or Indochina Peninsula from Philippines. Eventually, intensity of TCs is weaker than those in a positive AO phase due to the terrain effect caused by high passage frequency of TCs in mainland China.

Estimation of Solar Radiation Distribution Considering the Topographic Conditions at Jeju Island (지형조건에 따른 제주도의 일사량 분포 추정)

  • Park, Jin Ki;Park, Jong Hwa
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.1
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    • pp.39-48
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    • 2013
  • The solar radiation is the primary energy source that drives many of the earth's physical and biological processes and climate change. Understanding its importance to the solar radiation observation is a key to understanding a broad range of natural processes, agricultural, energy and human activities. The purpose of this study is to estimate solar radiation using sunshine duration, and to estimate distribution of solar radiation using a topography factor considering surface slope and aspect in complex terrain. The result of regression analysis between ratio of solar radiation and sunshine duration from 2001 to 2010 shows high $R^2$ value of 0.878. Regression analyses indicated that topographic attributes including elevation, slope and aspect had significant effects on solar radiation. The variation of topographic factor with aspect and slope for the summer and winter are considered. The highest month of daily mean solar radiation at Jeju island appears in April of 20.61 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$, and the lowest month appears in December of 6.90 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$. These results provided useful quantitative information about the influence of topography on solar radiation in the island region.

A Study on Water Quality Impact by Pollution Source in Yongwon Channel, Busan Newport (부산신항 용원수로에서의 오염원별 수질영향 조사)

  • Kwon, Jae Hyun;Kim, Young Do;Jung, Jae Hoon;Jeong, Weon Mu
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.2
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    • pp.185-196
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    • 2013
  • In Yongwon channel, its natural flow of seawater is blocked by the construction of Busan Newport including the container berth. The channel was transformed into a narrow and long one, where it is possible that ships are only allowed to pass through the north-side channel of Gyeonmado located at the point of river mouth to Songjeongcheon. In addition, Yongwon channel is approximately 100 m wide on average and 3,600 m long, which has the highest slenderness ratio (length/width=36). So it is considered that the changes in the terrain characteristics of Yongwon channel is likely to alter the circulation of sea water, thereby changing its water quality. In this study, the seasonal change and the spatial variation of the water quality in Yongwon channel was analyzed for the effect of land pollution using the measurement data. The mass balance calculation method is used to analyze the water pollution resulting from sediment pollutants. This result shows that the improvement of the water quality in Yongwon channel can be obtained from the sewer pipe modification and the environmental dredging.

The Relationship between the Pedestrian Movement Pattern and the Pedestrian Network at a University Campus (대학 캠퍼스 보행자 이동패턴과 보행네트워크간의 상호관련성)

  • Lee, Yu-Mi;Shin, Haeng-Woo
    • Journal of the Korean Institute of Educational Facilities
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    • v.21 no.2
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    • pp.25-32
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    • 2014
  • Many Korean university campuses are located on hilly terrain where the hierarchy of the path system is unclear. Therefore, it is difficult to analyze the pedestrian network through space syntax, in which only horizontal direction changes are considered as depths of space. The purpose of this study is to compare pedestrian movement patterns and space syntax analysis in order to find their relevance to each other and the relationship between them. We conducted a survey regarding the most-visited buildings and pathways at S-University, which is located on a hilly area in Seoul. The survey results were compared with the Space Syntax integration map by regression analysis. For the segments where the relationship between pedestrian volume and integration was weak, field observations were conducted. As a result, topographical aspects, functional aspects, and location aspects were observed as the main influential factors. In addition, the research proposes that adding an extra axial line per vertical directional change can potentially compensate for the low relevance of stairs. This study suggests the possibility and the necessity of three-dimensional space syntax programs and emphasizes the importance of campus planning for the pedestrian environment.

Application on the New Technology of Construction Structures Disaster Protection Management based on Spatial Information

  • Yeon, Sangho
    • International Journal of Internet, Broadcasting and Communication
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    • v.10 no.3
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    • pp.136-145
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    • 2018
  • The disaster monitoring technique by combination of the measurement method and the fine precision of the sensor collecting the satellite-based information that can determine the displacement space is available in a variety of diagnostic information and the GIS/GNSS by first sensor it is being requested from them. Be large and that the facility is operated nationally distributed torsional displacement of the terrain and facilities caused by such natural disasters progress of various environmental factors and the surroundings. To diagnose this spatial information, which contains the various sensors and instruments tracks the precise fine displacement of the main construction structures and the first reference in the Geospatial or more three-dimensional detailed available map and location information using the installed or the like bridges and tunnels produced to a USN/IoT change at any time, by combining the various positioning analysis of mm-class for the facility main area observed is required to constantly in the real time information of the USN/IoT environment sensor, and to utilize this as a precise fine positioning information by UAV/Drone to the precise fine displacement of the semi-permanent infrastructures. It managed to be efficient management by use of new technologies, analyzing the results presented to a method capable of real-time monitoring for a large structure or facility to construction disaster prevention.