• Title/Summary/Keyword: 정사항공사진

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A study on the change and cause of the channel in the midstream of singwang river and naeng river in pohang - Comparing the changes before and after typhoon hinnamnor with the past - (포항 신광천과 냉천 중류의 하도 변화와 그 원인에 대한 분석 - 과거 및 태풍 힌남노 전후 비교를 중심으로 -)

  • Seonggi An;Chanjoo Lee;Woo-Chul Kang;Jongmin Kim;Gyeonghyeon Min;Byungsun Yoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.61-61
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    • 2023
  • 우리나라는 여름철 집중호우 시 발생하는 홍수로 인해 중소하천의 확폭(Widening) 및 하안침식이 자주 발생하고 있으나, 이에 대해 홍수 피해 관점으로만 분석되고 있으며 체계적인 수리학적, 지형학적 분석은 미흡한 실정이다. 본 연구에서는 먼저, 1982-2022년의 지도 및 항공사진, 정사영상 등을 분석하여 포항시 신광천과 냉천 중류의 하도 변화를 살펴보고, 2022년 9월 태풍 힌남노의 내습 시 발생한 홍수로 인해 초래된 하도 변화를 분석하였다. 신광천 항사리 지점의 경우, 하천 우안에 제방이 축조되지 않았던 1982년에는 하폭이 상대적으로 넓었으나, 1992년 제방 축조 이후 우안 충적지가 하도에서 분리되며 하폭이 감소하였다. 2011년의 하도는 대부분의 면적이 식생으로 덮여 하천의 흐름이 잘 관찰되지 않으나, 2021년에 식생 제거로 하도가 식별되지만 하폭은 과거에 비해 더욱 감소하였다. 태풍 힌남노 내습 시 포항시의 6시간 누적 강우량은 315.3 mm 로 100년 빈도를 초과하는 집중호우가 발생하였으며, 그 결과 확폭이 발생하였다. 단면에서 보면 좌안 활주사면은 5 m 가량의 퇴적고를 보였고, 우안 공격사면은 평균 23.3 m 측방으로 침식되었다. 그 결과 1982년 하폭과 유사한 수준으로 확대되었다. 문덕리 지점(공장지대)과 냉천 용산리(아파트)의 경우에도 각각 평균 14 m, 18 m 의 하안침식을 보였다. 이러한 결과는 지난 30여 년 전 축조된 기존 제방이 유실되면서 발생한 것으로 홍수로 인해 과거의 하폭으로 복귀할 수 있음을 의미한다. 2022년 홍수에 의한 하도 변화와 같은 지형학적 변화를 고려할 때, 보다 안정적인 하천관리를 위해서는 하천 설계 시 과거 지도상의 하도 범위 및 기왕홍수로 인한 하안선 변동을 고려하는 것이 필요하다.

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Accuracy Assessment on the Stereoscope based Digital Mapping Using Unmanned Aircraft Vehicle Image (무인항공기 영상을 이용한 입체시기반 수치도화 정확도 평가)

  • Yun, Kong-Hyun;Kim, Deok-In;Song, Yeong Sun
    • Journal of Cadastre & Land InformatiX
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    • v.48 no.1
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    • pp.111-121
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    • 2018
  • RIn this research, digital elevation models, true-ortho image and 3-dimensional digital complied data was generated and evaluated using unmanned aircraft vehicle stereoscopic images by applying photogrammetric principles. In order to implement stereoscopic vision, digital Photogrammetric Workstation should be used necessarily. For conducting this, in this study GEOMAPPER 1.0 is used. That was developed by the Ministry of Trade, Industry and Energy. To realize stereoscopic vision using two overlapping images of the unmanned aerial vehicle, the interior and exterior orientation parameters should be calculated. Especially lens distortion of non-metric camera must be accurately compensated for stereoscope. In this work. photogrammetric orientation process was conducted using commercial Software, PhotoScan 1.4. Fixed wing KRobotics KD-2 was used for the acquisition of UAV images. True-ortho photo was generated and digital topographic map was partially produced. Finally, we presented error analysis on the generated digital complied map. As the results, it is confirmed that the production of digital terrain map with a scale 1:2,500~1:3,000 is available using stereoscope method.

Analysis of Non-Point Pollution Sources in the Taewha River Area Using the Hyper-Sensor Information (하이퍼센서 정보를 이용한 태화강지역의 비점오염원 분석)

  • KIM, Yong-Suk
    • Journal of the Korean Association of Geographic Information Studies
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    • v.20 no.1
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    • pp.56-70
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    • 2017
  • In this study, multi-image information for the central Taewha River basin was used to develop and analyze a distribution map of non-point pollution sources. The data were collected using a hyper-sensor (image), aerial photography, and a field spectro-radiometer. An image correction process was performed for each image to develop an ortho-image. In addition, the spectra from the field spectro-radiometer measurements were analyzed for each classification to create land cover and distribution maps of non-point pollutant sources. In the western region of the Taewha River basin, where most of the forest and agricultural land is distributed, the distribution map showed generated loads for BOD($kg/km^2{\times}day$) of 1.0 - 2.3, for TN($kg/km^2{\times}day$) of 0.06 - 9.44, and for TP($kg/km^2{\times}day$) of 0.03 - 0.24, which were low load distributions. In the eastern region where urbanization is in progress, the BOD, TN, and TP were 85.9, 13.69, and 2.76, respectively and these showed relatively high load distributions when the land use was classified by plot.

A Study on the Selection Method of Subject Parcel to Alter Land Category by Fuzzy GIS Analysis - Focused on Road State of Government Owned and Public Land - (퍼지 GIS 공간분석에 의한 지목변경 대상필지 선정방법에 관한 연구 - 국공유지 도로현황을 중심으로 -)

  • Cho, Tae-In;Choi, Byoung-Gil
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.3
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    • pp.57-66
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    • 2011
  • The purpose of this study is to research into a method of selecting the subject parcel with a change in the category of land given surveying the land alteration state focusing on the present state of road in the government-owned and public land by using the fuzzy membership function and GIS spatial analysis. It selected the old town center of Incheon Jung-gu, and the new downtown & the forest land of Gyeyang-gu as the research subject region, and carried out GIS spatial analysis on a serial cadastral map, urban planning road layer of Korea Land Information System, practical width of road layer of Road Name Address Management System & cadastral data base, and then calculated the suitable index for the subject parcel with a change in the category of land by using the fuzzy membership function with having the critical value as the area ratio of each parcel on a serial cadastral map that was incorporated into road layer or practical width of road layer. It finally selected the parcel, which is different in land category from the real land usage, as the final subject parcel for altering land category, by using the screen of visualizing the suitable index and the aerial ortho photograph. As a result of the final selection, the fuzzy GIS spatial analysis method, which was suggested in this study, is judged to be efficient in the selection period and the methodology compared to the existing manual method. It could be confirmed to be more suitable method for downtown than forest land and for the new downtown than the old town center.

Automatic Extraction of Training Dataset Using Expectation Maximization Algorithm - for Automatic Supervised Classification of Road Networks (기대최대화 알고리즘을 활용한 도로노면 training 자료 자동추출에 관한 연구 - 감독분류를 통한 도로 네트워크의 자동추출을 위하여)

  • Han, You-Kyung;Choi, Jae-Wan;Lee, Jae-Bin;Yu, Ki-Yun;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.2
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    • pp.289-297
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    • 2009
  • In the paper, we propose the methodology to extract training dataset automatically for supervised classification of road networks. For the preprocessing, we co-register the airborne photos, LIDAR data and large-scale digital maps and then, create orthophotos and intensity images. By overlaying the large-scale digital maps onto generated images, we can extract the initial training dataset for the supervised classification of road networks. However, the initial training information is distorted because there are errors propagated from registration process and, also, there are generally various objects in the road networks such as asphalt, road marks, vegetation, cars and so on. As such, to generate the training information only for the road surface, we apply the Expectation Maximization technique and finally, extract the training dataset of the road surface. For the accuracy test, we compare the training dataset with manually extracted ones. Through the statistical tests, we can identify that the developed method is valid.

The Application of Geospatial Information Acquisition Technique and Civil-BIM for Site Selection (지형공간정보취득기술과 토목BIM을 활용한 부지선정 연구)

  • Moon, Su-Jung;Pyeon, Mu-Wook;Park, Hong-Gi;Ji, Jang-Hun;Jo, Jun-Ho
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.6
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    • pp.579-586
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    • 2010
  • Due to the recent development of measuring technology and 3D programs, it has become possible to obtain various spatial data. This study utilizes the 2-dimensional data and 3-dimensional data extraction technology based on the existing empirical and statistical DB. The data obtained from geospatial data technology are integrated with civil engineering BIM to conduct the modeling of the topography of the target region and select the optimum location condition by using the cut and fill balance of the volume of earth. The target area is the land around Tamjin River, Jangheong-gun, Jeolla-do. The 3-dimensional topology linked with 3-dimensional mapping technology by using the orth-image and aerial LiDAR that uses aerial photo of the target area is visualized with Civil3D of AutoDesk. By using Civil3D program, the Thanks to the recent development of measuring technology and 3D programs, target area is analyzed through visualization and related data can be obtained for analysis. The method of using civil engineering BIM enables to obtain various and accurate information about the target area which is helpful for addressing the issues risen from the existing methodology. In this regard, it aims at searching for the alternatives and provides suggestions to utilize the information.

Wind Corridor Analysis and Climate Evaluation with Biotop Map and Airborne LiDAR Data (비오톱 지도와 항공라이다 자료를 이용한 바람통로 분석 및 기후평가)

  • Kim, Yeon-Mee;An, Seung-Man;Moon, Soo-Young;Kim, Hyeon-Soo;Jang, Dae-Hee
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.6
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    • pp.148-160
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    • 2012
  • The main purpose of this paper is to deliver a climate analysis and evaluation method based on GIS by using airborne LiDAR data and Biotop type map and to provide spatial information of climate analysis and evaluation based on Biotop type Map. At first stage, the area, slope, slope length, surface, wind corridor function and width, and obstacle factors were analyzed to obtain cold/fresh air production and wind corridor evaluation. In addition, climate evaluation was derived from those two results in the second stage. Airborne LiDAR data are useful in wind corridor analysis during the study. Correlation analysis results show that ColdAir_GRD grade was highly correlated with Surface_GRD (-0.967461139) and WindCorridor_ GRD was highly correlated with Function_GRD (-0.883883476) and Obstacle_GRD (-0.834057656). Climate Evaluation GRID was highly correlated with WindCorridor_GRD (0.927554516) than ColdAir_GRD (0.855051646). Visual validations of climate analysis and evaluation results were performed by using aerial ortho-photo image, which shows that the climate evaluation results were well related with in-situ condition. At the end, we applied climate analysis and evaluation by using Biotop map and airborne LiDAR data in Gwangmyung-Shiheung City, candidate for the Bogeumjari Housing District. The results show that the aerial percentile of the 1st Grade is 18.5%, 2nd Grade is 18.2%, 3rd Grade is 30.7%, 4th Grade is 25.2%, and 5th Grade is 7.4%. This study process provided both the spatial analysis and evaluation of climate information and statistics on behalf of each Biotop type.

A Study of the Current State of the Garden and Restoration Proposal for the Original Garden of Yi Cheon-bo's Historic House in Gapyeong (가평 이천보(李天輔) 고가(古家)의 정원 현황과 원형 복원을 위한 제안)

  • Rho, Jaehyun;Choi, Seunghee;Jang, Hyeyoung
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.118-135
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    • 2020
  • It is not uncommon in Korea to see the structure and function of a garden remain intact as well as its form. Yi Cheon-bo's Historic House (Gyeonggi-do Cultural Heritage Item No. 55), located in Sang-myeon, Gapyeong-gun, Gyeonggi-do, is considered an example of very valuable garden heritage, although its family history, location, and remaining buildings and natural cultural assets are not fully intact. Along with Yi Cheon-bo's Historic House, this study attempted to explore the possibility of restoration of the forest houses and gardens by highlighting the high value of Yi Cheon-bo's Historic House through research into the typical layout of private households in northern Gyeonggi Province and Gapyeong County, comparative review of aerial photographs from 1954, and interviews with those involved. The results of the study are as follows: In this study, the presence of Banggye-dongmun and Bansukam in the Banggyecheon area, where the location of the garden was well-preserved, was examined across the landscape of the outer garden, while the location of Yi Cheon-bo's Historic House, the appearance of feng shui, and the viewing axis were considered. Also, the appearance of the lost main house was inferred from the arrangement and shape of the Sarangchae and Haengrangchae that remain in the original garden, and the asymmetry of the Sarangchae Numaru and the hapgak shape on the side of the roof. In addition, the three tablets (Pyeonaeks) of Sanggodang (尙古堂), Bangyejeongsa (磻溪精舍), and Okgyeongsanbang (玉聲山房) were used to infer the landscape, use, and symbolism of the men's quarters. Also, a survey was conducted on the trees that existed or existed in the high prices. Incidentally, it was confirmed that information on boards and cultural properties of Yeonha-ri juniper (Gyeonggi-do Monument No. 61) was recorded to a much lesser extent than the actual required standard, and the juniper trees remaining in the front of Haengrangchae should also be re-evaluated after speculation. On the other hand, as a result of estimating the original shape as a way of pursuing completeness of the garden through restoration of the lost women's quarters and shrine, it is estimated that the main house was placed in the form of a '口' or a 'be warped 口' on the right (north) side of the men's quarters. By synthesizing these results, a restoration alternative for Yi Cheon-bo's Historic House was suggested.