• Title/Summary/Keyword: Topographical Characteristics

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Development of Synthetic Unit Hydrograph using River Fractal Characteristics (하천의 프랙탈 특성을 이용한 합성단위유량도의 개발)

  • 차상화
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.6
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    • pp.61-70
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    • 2002
  • This study was performed to analyze the river fractal characteristics using GIS (Geographic Information System). In this study, topographical factors in river basin were grid-analyzed for each cell size and scale using GIS and regression formula was derived by analyzing correlation among topographical factors and cell size which were calculated here. And, a new rainfall-runoff model which is considering the calculated fractal dimension was developed to apply fur a river basin.

Effect of watershed characteristics on the criteria of Flash Flood warning (유역인자의 특성이 경계경보발령 기준에 미치는 영향분석)

  • 양인태;김재철;김태환
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.389-392
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    • 2004
  • A recent unusual change in the weather is formed as a localized heavy rain in a short time. This phenomenon has caused a flash flood, and flash floods extensively have damaged human lives many times. In large river's case, the extent of loss of lives and properties has been decreased through the flood warning system by flood control stations of each stream. However, the extent of damage in other small rivers has increased reversely. Therefore, it is necessary to establish a new flood warning system against flash floods instead of the existing flood warning system. It is a specific character that the damage from flash floods in mountain streams brings much more loss of lives than large river's flood. The purpose of this study is calculating the characteristic of flash floods in streams, analyzing topographical characteristics of water basin through applying GIS techniques with the calculation as mentioned above and researching what topographical conditions have influence on hydrological flash floods in water basin. The flash flood prediction model we used is made by GIUH (geomorphoclimatic instantaneous unit hydrograph) with hydrologic-topographical technology. As applying the flash flood prediction model, this is a procedure for calculating topographical information in basin: we made a topological data up out of database with utilizing GIS, and we also produced a DEM (digital elevation model) and used it as a topographical data for determining amount of flash floods.

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The Anlysis of Fractal Characteristics in River Basin using GIS (GIS를 이용한 하천유역의 프랙탈 특성 분석)

  • Cha, Sang-Hwa;Kwon, Kee-Wook
    • Journal of the Korean Association of Geographic Information Studies
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    • v.4 no.4
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    • pp.51-60
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    • 2001
  • This study analyzed fractal characteristics of river basin by using GIS. In this study, topographical factors in river basin was grid-analyzed for each cell size by using GIS and regression formula was derived by analyzing correlation among topographical factors and cell size which were calculated here. And, analysis of fractal characteristics of river by using the result calculated from 1) showed that among topographical factors, river length only increases according as cell size increases. The result of calculating fractal dimension for each cell size shows that river length, basin area, and centroidal flow path are 1.028, 1.0026 and 1.0061 respectively.

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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.

Analysis on the Characteristics of the Landslide in Maeri (I) - With a Special Reference on Geo-Topographical Characteristics - (매리 땅밀림형 산사태(山沙汰)의 발생특성(發生特性)에 관한 분석(分析) (I) - 지형(地形) 및 지질특성(地質特性)을 중심(中心)으로 -)

  • Park, Jae-Hyeon;Choi, Kyung;Bae, Jong Soon;Ma, Ho-Seop;Lee, Jong-Hak
    • Journal of Korean Society of Forest Science
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    • v.94 no.3 s.160
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    • pp.129-134
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    • 2005
  • Ths study was carried out to understand the geo-topographical characteristics of the landslide area (1.5 ha) in Maeri, Sangdong-myeon, Gimhaesi, Gyeongsangnam-do. The bedrock of the landslide area was diollites and the area in and around the upper slope with the scattered talus was composed of Masanam originated from Igneous rocks. The landslide occurred in 19th of April, 2004 and the amount of rainfall for 3 days before the landslide was 74mm. The landslide by land creeping in this area was mainly attributed to geo-topographical characteristics such as well developed colluvial and/or weathered soils, and land cutting in lower slope, although the landslide could be affected by the rainfall. The type of the landslide can be classified into the land creeping by concave colluvial soils.

Characteristics of tidal current and mean flow at the west channel of Yeoja Bay in the South Sea of Korea (여자만 서수도 해역의 조류 및 조석평균류 특성)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.3
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    • pp.252-263
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    • 2019
  • In order to understand the tidal current and mean flow at the west channel of Yeoja Bay in the South Sea of Korea, numerical model experiments and vorticity analysis were carried out. The currents flow north at flood and south at ebb respectively and have the reversing form in the west channel. Topographical eddies are found in the surroundings of Dunbyong Island in the east of the channel. The flood currents flow from the waters near Naro Islands through the west channel and the coastal waters near Geumo Islands through the east channel. The ebb currents from the Yeoja Bay flow out along the west and the east channels separately. The south of Nang Island have weak flows because the island is located in the rear of main tidal stream. Currents are converged at ebb and diverged at flood in the northwest of Jeokgum Island. Tidal current ellipses show reversing form in the west channel but a kind of rotational form in the east channel. As the results of tide induced mean flows, cyclonic and anticyclonic topographical eddies at the northern tip but eddies with opposite spin at the southern tip are found in the west channel of Yeoja Bay. The topographical eddies around the islands and narrow channels are created from the vorticity formed at the land shore by the friction between tidal currents and the west channel.

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.