• Title/Summary/Keyword: topographical analysis

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Application of EOC Images to Developed the GIUH (지형학적순간단위유랑도 분석을 위한 EOC 스테레오 영상 활용)

  • Choi, Hyun;Kang, In-Joon;Hong, Sun-Heun
    • Korean Journal of Remote Sensing
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    • v.20 no.2
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    • pp.91-102
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    • 2004
  • This paper reflects the estimation of using the EOC(Electro-optical Camera) images supporting GIUH(geomorphological instantaneous unit hydrograph) approach. We have analyzed GIUH in its density and frequency distribution by creating a DEM(digital elevation model) for the sub basin produced from the EOC images and examined topographical and hydrological application possibility of the EOC images. In this process, we have topographical basin characteristic analysis that use the remote sensing technique analyzing the DEM creation process of the EOC stereo images by studying the basic topographical hydrology analysis about abstraction technique since it is flirty complex and is more time-consuming than other method. we executed statistical analysis of a basin size and river length using the frequency function after divided lattice spacing applied have to the sub river basin from the image data and the digital map into 10m intervals ranging from 10m to 100m. After comparing and examining the peak and time to peak of the GIUH, we proceeded with a comparative analysis by lattice concerning the topographical divergence rate, area ratio, length ratio. Accumulating the peak and time to peak of the GIUH is altered to non-linear form in accordance to lattice dimension as well as basin factor. It was proved that the lattice dimension is one of the important factors about the peak and time to peak of the GIUH.

A Study on Surface Landscape Change and Sedimentary Environment of the Dongcheon Estuary through Aerial Photographs and Sediment Analysis (항공사진 및 퇴적물 분석을 통한 순천 동천하구의 지표경관 변화 및 퇴적환경 연구)

  • Lee, Ye-Seul;Lim, Jeong-Cheol;Jang, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.28 no.1
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    • pp.35-50
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    • 2021
  • In this study, we analyzed the changes in the topographical landscape and the sedimentary environment to evaluate the ecological value of the Dongcheon Estuary and protect the wetland, and presented the conservation management method of the Dongcheon Estuary. Based on the result of topographical landscape analysis, agricultural land tended to decrease continuously, and artificial structures gradually increased. Moreover, in sediment analysis, the Dongcheon Estuary showed both the characteristics of river sediments and coastal sediments, and in some areas problems such as acidification and nutritional imbalance appeared. Therefore, in order to protect and manage the Dongcheon Estuary with high ecological value, it is necessary to limit the development around micro topography and minimize the artificial damage in the Dongcheon Estuary. In addition, efforts such as securing facilities for reducing pollutants and freshwater wetlands for pollutants, that flow in from nonpoint pollutants are required.

Vegetation Analysis Along Elevational and Topographical Gradients in Mt. Jumbong in Central Korea

  • Cho, Do-Soon;Lee, Kyu-Song
    • The Korean Journal of Ecology
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    • v.24 no.2
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    • pp.111-115
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    • 2001
  • Vegetational changes along elevational and topographical gradients were studied in Mt. Jumbong which is located at the core area of the Mt. Sorak Biosphere Reserve in Kangwon-do Province in central Korea. Two 500 m north-south transects crossing two valleys and a small ridge were laid out, and fifty-one 10 m$\times$10 m permanent quadrats were systematically set up. All trees bigger than 2.5 cm DBH were marked with numbered aluminum tags, and their DBH measured and the species identified. Coverage of plant species in the herb layer were determined in two 2 m $\times$ 2 m subquadrats in each of the permanent quadrats. Thirty-two species of woody plants occurred in the tree layer in the permanent quadrats studied. Quercus mongolica was the dominant species across the study site, and Acer pseudosieboldianum and Carpinus cordata were also important. Quercus mongolica occurred on the ridges and south-facing slopes, and Acer pseudosieboldianum occurred extensively except for valleys. In contrast, Fraxinus mandshurica, Acer mono, Acer triflorum, and Ulmus laciniata were common in valleys. At the herbaceous layer, 112 species were identified. Dominant species were Ainsliaea acerifolia and Sasa borealis on the ridges, Meehania urticifolia on north-facing slopes, and Deutzia glabrata on valleys. Soil environmental factors were compared among the quadrats. pH was lower in the quadrats located on ridges and south-facing slopes, and organic matter was lowest on south-facing slopes. Quadrats located on valleys were generally higher in pH, organic matter, N, P, K, Ca and Mg. DCA ordinations for tree layer and herb layer were carried out in order to identify the dominant environmental factors affecting the distribution of plant species along the environmental gradients. Correlation analysis between ordination axis scores and environmental factors showed that axis one was negatively correlated with elevation and positively correlated with soil organic matter, pH, Ca, Mg, and P, but that axis two was positively correlated with elevation. These results indicate that vegetation responds very sensitively to elevational and topographical gradients although the study area is relatively small with about 100 m in elevational variation.

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An Analysis for Goodness of Fit on Trigger Runoff of Flash Flood and Topographic Parameters Using GIS (GIS를 이용한 돌발홍수의 한계유량과 유역특성인자의 적합도 분석)

  • Oh, Myung-Jin;Yang, In-Tae;Park, Byung-Soo
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.3 s.37
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    • pp.87-95
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    • 2006
  • Recently, local heavy rain for a short term is caused by unusual changing in the weather. This phenomenon has, several times, caused an extensive flash flood, casualties, and material damage. This study is aimed at calculating the characteristics of flash floods in streams. For this purpose, the analysis of topographical characteristics of water basin through applying GIS techniques will be conducted. The flash flood prediction model we used is made with GCIUH (geomorphoclimatic instantaneous unit hydrograph). The database is established by the use of GIS and by the extraction of streams and watersheds from DEM. The streams studied are included small, middle and large scale watersheds. For the first, for the establishment or criteria on the flash flood warning, peak discharge and trigger runoff must be decided. This study analyzed the degree or aptitude of topographical factors to the trigger runoff calculated by GCUH model.

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A Case Study of Landslides due to Heavy Rainfall (집중호우시 산사태 원인분석에 관한 사례연구)

  • Yoo, Nam-Jae;Park, Byung-Soo
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.303-315
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    • 2001
  • This study is a research result of investigating causes of landslides occurred at Uijongbu in Kyonggi Province, Korea. For works of this research, informations and data about landslides occurred at the site, geological and topographical informations were collected to analyze causes of landslides, and mapping landslides was performed by using results of field investigation. Data about rainfall during occurrence of landslides around Uijongbu was also used to find the effect of intense rainfall on occurrence of landslides. Based on informations obtained from field investigation and collected data, the scale and the pattern of landslides were analyzed and influencing factors on landslide such as intensity and duration of rainfall, topography, geologic condition, geotechnical engineering properties of ground, forestry were investigated statistically to find causes of landslides. On the other hands, for geotechnical engineering respects, slope stability analysis was performed for the typical sites chosen from the sites where the landslides occurred, using informations obtained from detailed topographical survey with total stations, field reconnaissance and results from laboratory tests.

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Construction of the Curve Number Estimation System Using Geographic Information System (GIS를 이용한 CN 산정시스템 구축)

  • Chae, Jong Hun.;Jeong, In Ju;Kim, Sang Yong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.1262-1266
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    • 2004
  • The current combining of computer and geographic information technology. The result of such research oil determinate objective factors of hydrologic-topographical parameters through joining hydrology and GIS(Geographic Information System). In this study, we wish to offer the base data to determinate hydrologic-topographical parameters request of runoff model analysis in this basin. First, we computed the CN(curve number) by using GIS, and then classify the digital map of soil group and landuse on the Sulma river basin. Second, we used Avenue Script to calculate the height of efficient GIS work before using the Clark model to work out flood runoff flow.

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A study on the topographical and geotechnical effects in 2-D soil-structure interaction analysis under ground motion

  • Duzgun, Oguz Akin;Budak, Ahmet
    • Structural Engineering and Mechanics
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    • v.40 no.6
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    • pp.829-845
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    • 2011
  • This paper evaluates the effects of topographical and geotechnical irregularities on the dynamic response of the 2-D soil-structure systems under ground motion by coupling finite and infinite elements. A numerical procedure is employed, and a parametric study is carried out for single-faced slope topographies. It is concluded that topographic conditions may have important effects on the ground motion along the slope. The geotechnical properties of the soil will also have significantly amplified effects on the whole system motion, which cannot be neglected for design purposes. So, dynamic response of a soil-structure systems are primarily affected by surface shapes and geotechnical properties of the soil. Location of the structure is another parameter affecting the whole system response.

The Accuracy Estimation of Profile Generation for Planning using 3D Topographical Model (3차원 지형모델을 이용한 설계용 프로파일 생성 정확도 평가)

  • Um, dae-yong;Lee, eun-soo;Kim, ji-hye
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.892-896
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    • 2008
  • In construction work's process of a basic planning, we must carry out a topographical for construction reserved land and to the basis of this, production of profile is Indispensable factor for the purpose of every construction work such as road, rail way, canal and etc. From this research, the production of profile about construction reserved land, using topography information of numerical value topographical map produced by NGIS construction project, construct precision 3D topography model and from this, propose plans for utilizing by producing automatic profile. With the aim of this, abstract every layers of main facilities and altitude from numerical value topographical map and while producing 3D topography model by using this, we produce and product automatic profile from construct precision 3D topography. And about the produced profile's process, a topographical by mutual analysis was carried out to check whether the automatic produced profile's accuracy could be accepted at actual estimation and permissible accuracy. It is considered that the result of the research could be suggested as a new formation techniques concept which can reduce the designing time and expenses and increase the efficiency of planning in the basic design process for the construction.

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