• Title/Summary/Keyword: Topographic data

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Assessing the Influence of Topographic Factors on the Distribution of Aporia crataegi (Lepidoptera: Pieridae) in Northeast Asia Using a MaxEnt Modeling Approach (기후변화에 따른 상제나비의 잠재적 분포에 대한 지형요소의 영향 평가)

  • Kim, Tae-Geun;Cho, YoungHo;Song, Kyo-Hong;Park, YoungJun;Oh, Jang-Geun
    • Korean Journal of Ecology and Environment
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    • v.49 no.2
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    • pp.142-146
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    • 2016
  • The purpose of this study is to evaluate topographic characteristics revealed in the predicted distribution areas of Aporia crataegi, according to climate change. Towards this end, this study compared the differences of topographic factors, such as altitude, mountain slope and the aspect of slope, in the distribution areas with different potential inhabitation possibilities of the Aporia crataegi. The inhabitation possibilities of the Aporia crataegi were different, according to altitude and topographic slope, and the inhabitation possibility is judged to be affected more by the topographic conditions including altitude and mountain slope than by the aspect of slope. Especially, the inhabitation possibility of the Aporia crataegi was higher in the higher altitude area, as time goes on furthermore. The reason is that the current climate environment, which is suitable for the potential inhabitation of the Aporia crataegi, is forecast to be formed with an area with high altitude. Although the difference in the aspect of slope was not statistically significant according to inhabitation possibility, the reason why the inhabitation possibility of the Aporia crataegi varies in the mainly southeast slope is conjectured to be derived from the warmer heat environmental condition to grow from a larva into an imago. The result drawn in this study is expected to be utilized as basic data to establish a policy soundly preserving and managing the habitat of biospecies in consideration of climate change and topographic conditions in the natural ecosystem field by using the already built up various biological resources information.

The Development of Process for Transforming Cadastral Map to Be Referred to KGD2002 (지적도면의 세계측지계 변환을 위한 프로세스 개발)

  • Hwang, Jin-Sang;Yun, Hong-Sic;Song, Dong-Seob;Kang, Ji-Hun
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.439-442
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    • 2007
  • This study is on the development of optimal method for transforming cadastral map to be referred to KGD2002. The method was developed by referring to the method used at transforming Korean National Digital Topographic Map to be referred to KGD2002 and analysing the records about making cadastral map. We tested the method by transforming the cadastral maps of three sample sites and analysing the accuracy of transformed maps. It was proved that the method could be used at transforming cadastral map to be referred to KGD2002 for the propose of being related to National Digital Topographic Map, National GIS data, and so on. We also introduce the longitudinal process for transforming national cadastral maps to be used as a data to verify land ownership.

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Analysis of Steep slope Disaster Sites using Geographic Information System (GIS를 활용한 급경사지 재해현장 분석 -전북 무주군, 장수군, 진안군 중심으로-)

  • Lee, Min-Seok;Oh, Jeong-Rim;Park, Dug-Keun;Kim, Man-Il
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.940-945
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    • 2010
  • There are human casualties that caused by slope-stability related disasters such as landslide and debris flow during typhoon and rainy season every year in Korea. These disaster sites can be analyzed systematically using digital topographic data and aerial photogrammetry. In this study, geographical factors such as slope degree, geology, height, and soil depth are analyzed in four landslide-disaster sites from Muju, Jinan, and Jangsu County based on digital elevation maps generated by ArcGIS. Each site showed different characteristics in geology and geography and it is found that GIS can be utilized for the visualization of steep-slope failure areas.

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Interpretation of recent topographic changes using the DEM data in the eastern part of Ulsan fault zone (DEM자료를 이용한 울산단층대 동부지역의 최근 지형변화 해석)

  • 신정환;최원학;장천중
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.11-18
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    • 2002
  • The Ulsan fault with NNW-SSE strike is a very wide and long lineament about 50km along Gyeungju-Ulsan line in the southeastern part of Korea. According to previous studies the Ulsan fault was not considered as a fault but only long lineament since no displacement was found along the lineament. Recently several Quaternary faults were reported in the northeastern part of lineament, which implies the neotectonic movement in this area. We analysed drainage pattern and stream gradient using the DEM (Digital Elevation Model) data for both side of Ulsan fault line to check the recent topographic changes which indicate neotectonic movement. The result shows that stream index in the eastern part of Ulsan fault is higher than the one in the western part. This means that recent tectonic movement is more active in the eastern part of Ulsan fault.

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Landslide Susceptibility Analysis of Clicap, Indonesia

  • Kim, I. J.;Lee, S.;Choi, J. W.;Soedradjat, Gatot Moch
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.141-143
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    • 2003
  • The aim of this study is to evaluate the susceptibility of landslides at Clicap area, Indonesia , using a Geographic Information System (GIS). Landslide locations were identified from field surveys. The topographic and geological map were collected and constructed into a spatial database using GIS. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography, were calculated from the topographic database and lihology and fault was extracted from the geological database. Then landslide susceptibility was analyzed using the landslide-occurrence factors by likelihood methods. The results of the analysis were verified using the landslide location data. The GIS was used to analyze the vast amount of data efficiently . The results can be used to reduce associated hazards, and to plan land use and construction.

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Accuracy Analysis of Topographic Survey Data for the Official Land Price Appraising (공시지가산정을 위한 지형·지세조사 자료의 정확도 분석)

  • Lee, Chang-Han;Sung, Chun-Ja
    • Journal of Cadastre & Land InformatiX
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    • v.48 no.1
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    • pp.153-167
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    • 2018
  • Despite many criticisms that topographic survey data for the official land price appraising collected annually using field survey method might be inaccurate, there is only few concrete research on it. This paper investigated whether the topographic survey data collected by a local government using field survey method is consistent with the data analyzed using the digital elevation model to examine its accuracy. The accuracy analysis indicated that 324 out of 1537 lots of land have inconsistent results which means the ratio of inconsistency is 17.36%. Among 11 areas studied, five had the inconsistency ratio above 20% while the worst one had 38.71%. The inconsistency ratio is generally higher for the rough terrain with irregular slope and high altitude while it is relatively lower for the terrain with smooth landform. The analysis results imply that there are limitations in investigating the topology by field survey method. Therefore, the official land price appraising policy should set precise criterion and change over to highly accurate geographic information analysis method to effectively and accurately examine topology, given the fact that the topology of the Republic of Korea has complicated features with irregular slope and altitude.

3D Surface Model Reconstruction of Aerial LIDAR(LIght Detection And Ranging) Data Considering Land-cover Type and Topographical Characteristic (토지피복 및 지형특성을 고려한 항공라이다자료의 3차원 표면모형 복원)

  • Song, Chul-Chul;Lee, Woo-Kyun;Jeong, Hoe-Seong;Lee, Kwan-Kyu
    • Spatial Information Research
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    • v.16 no.1
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    • pp.19-32
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    • 2008
  • Usually in South Korea, land cover type and topographic undulation are frequently changed even in a narrow area. However, most of researches using aerial LIDAR(LIght Detection And Ranging) data in abroad had been acquired in the study areas to be changed infrequently. This research was performed to explore reconstruction methodologies of 3D surface models considering the distribution of land cover type and topographic undulation. Composed of variously undulatory forests, rocky river beds and man-made land cover such as streets, trees, buildings, parking lots and so on, an area was selected for the research. First of all, the area was divided into three zones based on land cover type and topographic undulation using its aerial ortho-photo. Then, aerial LIDAR data was clipped by each zone and different 3D modeling processes were applied to each clipped data before integration of each models and reconstruction of overall model. These kinds of processes might be effectively applied to landscape management, forest inventory and digital map composition. Besides, they would be useful to resolve less- or over-extracted problems caused by simple rectangle zoning when an usual data processing of aerial LIDAR.

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Geomorphologic Nash Model with Variable Width Function

  • Thuy, Nguyen Thi Phuong;Kim, Joo-Cheol;Jung, Kwansue
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.212-212
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    • 2015
  • So far, geomorphologic dispersion due to the heterogeneity characteristics of flow paths in a basin has been demonstrated as a major factor affecting to the hydrologic response function of a catchment. This effect has considered by many previous studies taking into account flow path length factors, especially in the application of width function. Based upon the analysis of topographic index, another important geomorphologic factor extracted from DEM data, this work presents a new factor named saturation to evaluate its effects to the formation of the well-known instantaneous unit hydrograph (IUH) in Nash model and drainage structure in a river basin. First, the geomorphologic parameters corresponding to different saturation conditions are computed from DEM data with the support of GIS software. Then, in the combination of hydrologic and geomorphologic data, effective rainfall in each saturation degree and the Nash parameters are calculated using excel. Finally, the verification process with direct runoff data is conducted using Fortran programming. This process is applied to five sub-watersheds in Bocheong catchment ($485.21km^2$) in Korea where the necessary data are available and believable. The results from this approach will improve researchers and students'understandings about the relationship between rainfall and runoff and its relation with drainage structure within a catchment.

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Assessment of Topographic Normalization in Jeju Island with Landsat 7 ETM+ and ASTER GDEM Data (Landsat 7 ETM+ 영상과 ASTER GDEM 자료를 이용한 제주도 지역의 지형보정 효과 분석)

  • Hyun, Chang-Uk;Park, Hyeong-Dong
    • Korean Journal of Remote Sensing
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    • v.28 no.4
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    • pp.393-407
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    • 2012
  • This study focuses on the correction of topographic effects caused by a combination of solar elevation and azimuth, and topographic relief in single optical remote sensing imagery, and by a combination of changes in position of the sun and topographic relief in comparative analysis of multi-temporal imageries. For the Jeju Island, Republic of Korea, where Mt. Halla and various cinder cones are located, a Landsat 7 ETM+ imagery and ASTER GDEM data were used to normalize the topographic effects on the imagery, using two topographic normalization methods: cosine correction assuming a Lambertian condition and assuming a non-Lambertian c-correction, with kernel sizes of $3{\times}3$, $5{\times}5$, $7{\times}7$, and $9{\times}9$ pixels. The effects of each correction method and kernel size were then evaluated. The c-correction with a kernel size of $7{\times}7$ produced the best result in the case of a land area with various land-cover types. For a land-cover type of forest extracted from an unsupervised classification result using the ISODATA method, the c-correction with a kernel size of $9{\times}9$ produced the best result, and this topographic normalization for a single land cover type yielded better compensation for topographic effects than in the case of an area with various land-cover types. In applying the relative radiometric normalization to topographically normalized three multi-temporal imageries, more invariant spectral reflectance was obtained for infrared bands and the spectral reflectance patterns were preserved in visible bands, compared with un-normalized imageries. The results show that c-correction considering the remaining reflectance energy from adjacent topography or imperfect atmospheric correction yielded superior normalization results than cosine correction. The normalization results were also improved by increasing the kernel size to compensate for vertical and horizontal errors, and for displacement between satellite imagery and ASTER GDEM.