• Title/Summary/Keyword: Topographical characteristics

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Developing of Forest Fire Occurrence Danger Index Using Fuel and Topographical Characteristics on the Condition of Ignition Point in Korea (산불발화지점의 임상 및 지형특성을 이용한 산불발생위험지수 개발)

  • Lee Si-Young;Won Myoung-Soo;Han Sang-Yoel
    • Fire Science and Engineering
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    • v.19 no.4 s.60
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    • pp.75-79
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    • 2005
  • This study has developed Forest Fire Occurrence Danger Index (FFODI) using fuel and topographical characteristics for the practical purposes of forecasting forest fire occurrence danger rating. This was made on the basis of the 126 forest fire site according to field survey. The result of fire frequency analysis showed 87 sites on conifer $(69\%)$, 21 on mixed $(16.7\%)$ and 18 $(14.3\%)$ on non-conifer. The scale for Fuel Model Index(FMI) ranges from 1 to 10 and Topography Model Index(TMI) from 1 to 5. FMI is 10 on the conifer, 3 on the mixed and 2 on the non-conifer. In case of topographical analysis, it was estimated that 90 site $(71.4\%)$ of ignition point was bottom foot hill and 22 site $(17.5\%)$ was on the southwest. TMI in southwest direction is 5.0, 4.5 in the northwest and the northeast, 4.0 in the southeast and the south, 2.5 in the north and the west and 1.5 in the east. TMI in the bottom foot hill is 5 in the bottom foot hill, 1.5 in the upper foot hill, 1.0 in the bottom middle slope and 0.5 in the upper middle slope and bottom ridge.

Analysis of Topographical Factors in Woomyun Mountain Debris Flow Using GIS (GIS를 이용한 우면산 토석류 지형인자 분석)

  • Lee, Hanna;Kim, Gihong
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.5
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    • pp.809-815
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    • 2020
  • A number of investigations and studies have been conducted in various fields regarding the sediment disasters of Mt. Woomyeon that occurred in July 2011. We collected and compared the topographic information of the general points where debris flows did not occur and the collapse points where the debris flow occurred in order to find out the characteristics of the collapse points in Woomyeon mountain. The collected topographic information is altitude, curvature, slope, aspect and TPI(topographic position index). As a result of comparison, there were relatively many collapse points at an altitude of 210m to 250m, and at a slope of 30° to 40°. In addition, the risk of collapse was low in a cell where the curvature was close to 0, and the risk was higher in concave terrain than in convex terrain. In the case of TPI, there was no statistical difference between the general points and the collapse points when the analysis radius was larger than 200m, and there was a correlation with the curvature when the analysis radius was smaller than 50m. In the case of debris flows that are affected by artificial structures or facilities, there is a possibility of disturbing the topographic analysis results. Therefore, if a research on debris flow is conducted on a mountain area that is heavily exposed to human activities, such as Woomyeon mountain, diversified factors must be considered to account for this impact.

An Analysis of Micro-landform and Its Grain Size of Tidal Flat in Gomso-Bay using Satellite Remote Sensing (위성원격탐사를 이용한 곰소만 간석지의 미지형과 퇴적물 입도특성 분석)

  • Jo, Wha-Rhong;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.1
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    • pp.44-56
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    • 2000
  • Through the ISODATA method of unsupervised classification, the micro-landform of Gomso-Bay tidal flat was classified into mud, mixed, and sand flats by using Landsat TM image. Each tidal flat shows on apparent differences in its topographical characteristics and grain size compositions. Mud flat is occupied the innermost part of the tidal flat. Sand flat is distributed adjacent to the entrance of the bay, while the mixed one is located in the central part of the bay. Mud flat deposits have fine grain size, more than 4 in average mean phi, bad sorting, more than 1 phi in standard devation, and positive skewness. Mixed and sand flat deposits have coarse grain size, less than 4 average mean phi, good sorting, less than 1 phi in standard daviation, and negative skewness. Topographically, the mud flat consists of flat surfaces and dissected channels. The average depth of dissected channels is about 2 meters. Meanwhile, sand flat has a very flat landform with well-developed ripple marks of less than 10 centimeters in average relief. And the mixed one shows the intermediate topographical characteristics of those of mud and sand flats.

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Environmental Impact Assessment of Fish Cage Farms Using Benthic Polychaete Communities (저서 다모류군집을 이용한 어류가두리 양식장의 환경영향범위 평가)

  • Park, Sohyun;Kim, Sunyoung;Sim, Bo-Ram;Jung, Woo-Sung;Park, Se-Jin;Hong, Sok-Jin;Lee, Won-Chan;Yoon, Sang-Pil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.5
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    • pp.598-611
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    • 2022
  • The aim of this study was to investigate the range of influence of aquaculture activities in fish cage farms located on the southern coast of Korea (Farm A and B in Hadong, Farm C in Tongyoung, and Farm D in Geoje) by analyzing the distribution and characteristics of polychaete communities. Farm A and B showed remarkably high aquaculture intensity, and as a result, the polychaete communities near the farms were heavily polluted. However, there was a difference in the polychaete communities at a distance greater than 30 m from farm A and B, which may be due to topographical differences. The effect of the aquaculture activity of Farm C was only observed below the farm, however, the influence of aquaculture activities Farm D was maintained over a relatively long distance. According to the results of this study, the effect of the fish cage culture was mainly influenced by factors related to the production of fish, such as the stocking amount and the amount of food supply. Moreover, the distance at which the influence of aquaculture activity was observed was found to be closely related to the topographical characteristics and flow velocity around the farms.

Analysis of Geomorphological Characteristics of Bukhan River Basin based on Hydrologic Unit Map (수자원 단위지도를 기반으로 한 북한강 유역의 지형학적 특성 분석)

  • Park, Geun-Ae;Kwon, Hyung-Joong;Kim, Seong-Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3B
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    • pp.241-251
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    • 2006
  • This study analyzed the topographical characteristics by extracting property factors of stream (stream order, number of stream, stream length, mean stream length) and property factors of basin (basin area, basin length, total stream length, total number of stream, basin mean width, form factor, maximum stream order, basin density, stream frequency, relief ratio, mean elevation, mean, slope, maximum elevation) from DEM (digital elevation model) and stream network generated by 1:5,000 NGIS (national geographical information system) data for the Bukhan-river basin. In addition, topographical factors for upper, mid stream and lower stream were analyzed and the mutuality of the factors by linear and nonlinear regression curve was identified.

A Study on the Typological Classification and Characteristics of Contemporary House Plans (현대주택 평면의 유형화와 평면 특성 분석에 관한 연구)

  • 이현수;정승연;최진원
    • Journal of the Korean housing association
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    • v.10 no.2
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    • pp.195-202
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    • 1999
  • The purpose of this study is to analyze the characteristics and types of contemporary houses. This study deals with single-unit Korean houses designed by architects, which are included in architectural periodicals and books published since 1990. This study uses three analysis criteria: general characteristics of the house, hierarchical order of the plan and planning elements of houses. These criteria are derived from preceding studies and typological and topographical theories on houses. As the results of this study, the types of contemporary houses's plan are obtained from the perspective of plan's shape, hierarchical space relationship and spatial organization. Ten types corresponding to the plan shape are proposed. And eleven types of hierarchical space relationship are made and six spatial organization plan types are shown in this paper.

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The Characteristics Analysis of Landslides and Rainfall at Pusan Area (부산지역에서의 강우와 산사태의 특성분석)

  • Han, Jung-Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.1
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    • pp.24-31
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    • 2001
  • Most of the natural calamities occurred in South Korea are due to rainfall, which are occurred during rainy season, June to September. The life-calamity reported in those seasons were over 75%, and the dead rate by the rainfall was about 98%. Especially, the disasters occurred in Pusan and Kyongsang-Namdo were highest of the whole country. The capability of landslide in this area was very high, which is included to Class 3 or Class 4 of disastrous risk grade suggested by the GIS system(Lee Su-Gon,1999). Those are based on the characteristics of topographical and meteorological data. In this study, the rainfall characteristics in Pusan were analyzed through the relationship between the cumulative rainfall and the maximum hourly rainfall. The landslide in this area depends on the elapsed time after maximum hourly rainfall intensity, and the most of landslide in Pusan recorded during within 3 hours after pick-time of rainfall intensity.

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Property Analyses of Deposits and Landform in Tidal Flat using Satellite Image

  • Jo, Myung-Hee;Sugimori, Yasuhiro;Jo, Wha-Ryong
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.110-115
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    • 1998
  • Through the ISODATA method, the micro-landform of Julpo-Bay tidal flat was classified into mudflat, mixedflat, and sandflat using Landsat TM image. Each showed an apparent differences in its topographical characteristics and grain size composition. For example, mudflats are formed with flat faces and tidal channel of dissected gully. Its characteristics of grain size analysis that the grains have less than mean grain size 4 phi. Its sorting is bad (higher than 1 S.D.), and it showed strongly positive skewness. But sandflat is topographically flat without tidal channel. It has developed with ripple marks. According to the grain size analysis of deposits, the soil is coarse size with 90% of sand and its sorting is well(lower than 1 S.D.) Also, it showed strongly negative skewness. Mixed flat is in between mudflat and sandflat in its characteristics.

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Geotechnical Characteristics of Soft Clayey Soil in South Korea (국내 연약 점성토 지반의 지반공학적 특성)

  • Oh, Seo-Hyun;Ha, Tae-Gyun;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.922-929
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    • 2009
  • In this paper, 4 representative soft clayey soils in south Korea are selected to estimate the geotechnical characteristics and provide the instructions avaliable for construction works; Inchon Coast, Kum River Estuary, Kwangyang Bay, and Nakdong River Estuary. Total 2250 boring data are collected to construct the data base system on selected areas from Korea geotech DB system, scientific journals, theses, and site investigation reports. Considering the geological, topographical and regional features, geotechnical properties, deformation and strength characteristics of 4 soft clayey soils are evaluated by analyzing the constructed DB system statistically.

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A Case Study on Characteristics of Landslides in Natural Slopes (자연사면 산사태 특성에 관한 사례 연구)

  • Yoo, Nam-Jae;Jun, Sang-Hyun;Park, Nam-Sun
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.193-199
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    • 2007
  • This paper is a result of a case study about landslides at Whacheon area in Kangwondo occurred during heavy rainfall in 2006. A-day-accumulative rainfalls from July 12 to July 13 and July 15 to July 16 were 120mm and 110mm respectively. Five sites at which slope failures occurred were visited to figure out main causes of slope failures by investigating characteristics of rainfall, geological formation, topography and ground surface exploration around the boundary of the landslides. Based on the site investigation characteristics of landslide with respect to rainfall pattern, geological and topographical condition and pattern of landslide were evaluated.

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