• Title/Summary/Keyword: Mountainous area

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Analysis of Debris Flow Disaster Area according to Location Change of Check Dam using Kanako-2D (Kanako-2D를 이용한 사방댐 위치 변화에 따른 토석류 피해지 분석)

  • Kim, Young Hwan;Jun, Kye-Won
    • Journal of the Korean Society of Safety
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    • v.33 no.1
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    • pp.128-134
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    • 2018
  • With the increase in frequency of typhoons and heavy rains following the climate change, the scale of damage from the calamities in the mountainous areas has been growing larger and larger, which is different from the past. For the case of Korea where 64% of land is consisted of the mountainous areas, establishment of the check dams has been drastically increased after 2000 in order to reduce the damages from the debris flow. However, due to the lack of data on scale, location and kind of check dams established for reducing the damages in debris flow, the measures to prevent damages based on experience and subjective basis have to be relied on. Under this study, the high-precision DEM data was structured by using the terrestrial LiDAR in the Jecheon area where the debris flow damage occurred in July 2009. And, from the numerical models of the debris flow, Kanako-2D that is available to reflect the erosion and deposition action was applied to install the erosion control facilities (water channel, check dam) and analyzed the effect of reducing the debris flow shown in the downstream.After installing the erosion control facilities, most of debris flow moves along the water channel to reduce the area to expand the debris flow, and after installing the check dam, the flow depth and flux of the debris flow were reduced along with the erosion. However, as a result of analyzing the diffusion area, flow depth, erosion and deposition volume of the debris flow generated from the deposition part after modifying the location of the check dams with the damages occurring on private residences and agricultural land located on the upstream area, the highest reduction effect was shown when the check dam is installed in the maximal discharge points.

A Study on Flash Flood Warning in Mountainous Area (산악지역 돌발홍수 경보발령 기준 설정에 관한 연구)

  • Jun, Kye-Won;Oh, Chae-Yeon;Yeon, Gyu-Bang;Lee, Seung-Chul;Jun, Byong-Hee
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.591-594
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    • 2007
  • The purpose of this study is to estimate the critical flood discharge and flash flood trigger rainfall for alarm system providing for a flash flood in mountainous. This study was effectively estimated a topographic characteristic factor of basin using the GIS. Especially, decided stream order using GIS at stream order decision that is important for input variable of GCIUH. Result that calculate threshold discharge to use GCIUH, at the Mureung valley basin, flash flood trigger rainfall was 16.34mm in the first 20 minutes when the threshold discharge was $14.54\;m^3/sec$.

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Analysis for Forest Fire Damage Severity Map in Cheongyang

  • Jung Tae-Woong;Yoon Bo-Yeol;Yoo Jae-Wook;Kim Choen
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.537-540
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    • 2004
  • Space-borne multi-sensor data could provide fire scar and bum severity mapping. This paper will present detail mapping of burnt areas in Cheongyange Yesan of Korea with ETM+ image. Burn severity map based on ETM+ image was found to be affected by strong topographic illumination effects in mountainous forest area. Topographic effect is a factor which causes errors in classification of high spatial resolution image like IKONOS image. Minnaert constants J( in each band of ETM+ image is derived for reduction of mountainous terrain effects. Finally, this paper computes quantitative analysis of forest fire damage by each forest types.

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Regional Revitalization and Settlement Improvement from the point of view of the Local Residents - A Case Study on the Nakathu-Mura of Wakayama Prefecture in Japan - (지역주민의 시각에 의한 정주환경개선과 지역활성화 - 일본 와카야마현 나카츠무라를 중심으로 -)

  • Kim, Young-Joo;Choi, Soo-Myung;TAKAHASHI, Tsuyoshi
    • Journal of Korean Society of Rural Planning
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    • v.10 no.3 s.24
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    • pp.19-26
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    • 2004
  • In this study, a new model for improving the settlement environment and revitalizing hilly and mountainous areas was presented. A case study was conducted in two rural villages of Nakatsu-Mura in Wakayama-Prefecture, Japan. The settlement environment was evaluated from the point of view of the local residents, and the expectation of the local residents about the regional revitalization of their village in the future was assessed. From the analysis, each factor used far the assessment displayed characteristics of the two rural villages well. The type of improvement in rural villages was classified by a combination of the degree of satisfaction over the current settlement environment and expectation about the regional revitalization of the villages in the future. A method for improving and revitalizing settlement environments was clarified.

GEOMETRIC COREGISTRATION FOR TERRASAR-X INTERFEROMETRY

  • Yoon, Geun-Won;Kim, Sang-Wan;Lee, Yong-Woong;Won, loong-Sun
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.251-254
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    • 2008
  • The German radar satellite TerraSAR was launched in 2007. In this study, interferogram is generated using TerraSAR-X data and DEM (Digital Elevation Model). Coregistration procedures used with SAR images (i.e. master and slave) in traditional method results in serious errors for high resolution TerraSARX data because of the mutual shift of the master and slave images due to topography. This error becomes more serious in mountainous areas in which the coherence between interferometric pairs is relatively low. Here we processed a geometric coregistration with DEM exploiting height information. Through the method, interferometry processing is fulfilled to generate a qualified interferogram and coherence is improved. This approach will help high resolution X-band SAR interferometry in mountainous area.

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Risk Assessment by Vehicle Speed Difference in Climbing Lanes

  • Oh, Heung-Un;Kang, Jin-Gu
    • International Journal of Safety
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    • v.9 no.1
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    • pp.47-53
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    • 2010
  • The speed difference in mountainous area is known causing traffic conflicts and accidents. Thus, climbing lanes have popularly been installed in mountainous roads around the world. In the present paper, vehicle speeds within and around climbing lanes of Ho-nam and Jung-ang expressway were collected and evaluated. The evaluation was performed in terms of coefficient of variations which represent dispersion of vehicle speed in climbing lanes. Results show that speed dispersion is more significant at segments before and after climbing lanes than those within climbing lanes. The estimated accident risk was evaluated using The Solomon's u-shaped curve. It was identified that the accident risk is also a lot significant at the same segments as much as 2.2 times greater than those of climbing lanes.

International Research Trend on Mountainous Sediment-related Disasters Induced by Earthquakes (지진 유발 산지토사재해 관련 국외 연구동향 분석)

  • Lee, Sang-In;Seo, Jung-Il;Kim, Jin-Hak;Ryu, Dong-Seop;Seo, Jun-Pyo;Kim, Dong-Yeob;Lee, Chang-Woo
    • Journal of Korean Society of Forest Science
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    • v.106 no.4
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    • pp.431-440
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    • 2017
  • The 2016 Gyeongju Earthquake ($M_L$ 5.8) (occurred on September 12, 2016) and the 2017 Pohang Earthquake ($M_L$ 5.4) (occurred on November 15, 2017) caused unprecedented damages in South Korea. It is necessary to establish basic data related to earthquake-induced mountainous sediment-related disasters over worldwide. In this study, we analyzed previous international studies on the earthquake-induced mountainous sediment-related disasters, then classified research areas according to research themes using text-mining and co-word analysis in VOSviewer program, and finally examined spatio-temporal research trends by research area. The result showed that the related-researches have been rapidly increased since 2005, which seems to be affected by recent large-scale earthquakes occurred in China, Taiwan and Japan. In addition, the research area related to mountainous sediment-related disasters induced by earthquakes was classified into four subjects: (i) mechanisms of disaster occurrence; (ii) rainfall parameters controlling disaster occurrence; (iii) prediction of potential disaster area using aerial and satellite photographs; and (iv) disaster risk mapping through the modeling of disaster occurrence. These research areas are considered to have a strong correlation with each other. On the threshold year (i.e., 2012-2013), when cumulative number of research papers was reached 50% of total research papers published since 1987, proportions per unit year of all research areas should increase. Especially, the proportion of the research areas related to prediction of potential disaster area using aerial and satellite photographs is highly increased compared to other three research areas. These trends are responsible for the rapidly increasing research papers with study sites in China, and the research papers examined in Taiwan, Japan, and the United States have also contributed to increases in all research areas. The results are could be used as basic data to present future research direction related to mountainous sediment-related disasters induced by earthquakes in South Korea.

Relationship between Thermal Low and Long-Range Transport of Air Pollutants (대기오염물질의 장거리 수송과 열적저기압의 관계)

  • 이화운;김유근;김해동;정우식;현명숙
    • Journal of Environmental Science International
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    • v.10 no.2
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    • pp.143-151
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    • 2001
  • The atmospheric conditions and the transport mechanism of long-range transport of air pollutants from coastal area to inland area were investigated using regular meteorological data and air pollution data obtatined from the southeastern area of Korea. Daytime temperature over the inland area(Taegu) was higher than that over the coastal area(Pusan) and the temperature difference of about 5~6$^{\circ}C$ when the thermal low most fully developed and the sea level pressure over Taegu was lower than that over Pusan by about 4~5hPa at that time. Therefore this low pressure appeared to the thermally induced low. Air mass polluted from the coastal area during the morning period was transported inland area, at first by the sea breeze and by the large scale wind system toward the thermal low generated in the mountainous inland region. This was explained by the fact that the concentration of air pollutants over Taegu increased throughtout the late afternoon.

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Riparian forest and environment variables relationships, Chichibu mountains, central, Japan (일본 Chichibu산지 계반림의 입지환경)

  • Ann, Seong-Won
    • Journal of Environmental Science International
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    • v.12 no.2
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    • pp.93-100
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    • 2003
  • In most mountainous parts of the temperate zone of Japan along the Pacific Ocean, some climatic climax forests, whose main dominant species is Fagus crenate, F. japonica or Quercus mongolica var. grosseserrata, are distributed. In the riparian regions of the zone, however, there appear summer green forests composed of the different species from the climatic climax forests. Climate plays an important role in determining the overall distribution of vegetation, but some environmental factors, i.e., topography, soil type, soil moisture content, etc. have a great influence on vegetation formation. Riparian forests seem to be controlled by various geomorphologic disturbances, such as landslide, soil erosion and accumulation. The study aims to present the relationships among vegetation, soils and landforms in the process of determining riparian forests dominated by Fraxinus platypoda and Pterocarya rhoifolia establishment in the mountainous region of central Japan. The study area extends an area of 302 ha with a range of elevation between 925 m and 1,681 m at the Chichibu mountains. The landforms were corditied at sampling grids (25 $\times$ 25 m, n = 4,843) using a hierarchical system, and a brief description of the forest soil classification was also given. The mutual relationship analysis indicated that forest soils and landforms play a significant role in determining the geomorphological process of riparian forest, and shaping the ultimate pattern of vegetation. At the study area, riparian forests were mainly found on the $B_E$ forest soil type and steep slopes ( > 30$^{\circ}$) at convex slopes along the streams. On the other hand, the direction of slopes did not have a significant impact on the establishment of the riparian forests. A mosaic of patchy distribution of those riparian forests on the slightly wetter $B_E$ forest soil type was one of the characteristic features of the study area. This particular soil which contained large talus gravels was found on the land formed by erosion and deposition of landslide.

A Study on the Locational Condition of Rural Life Style Pensions - Focused on the Geumsan Area - (농촌생활형 펜션의 입지환경에 관한 연구 - 금산지역을 중심으로 -)

  • Do, Yong-Ho
    • Journal of the Korean Institute of Rural Architecture
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    • v.10 no.1
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    • pp.11-18
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    • 2008
  • The Geumsan is contiguous to Daejeon and population is decreasing every year. Consequently, the population influx, and securing source of revenue dimensional geographic and environmental benefits of the establishment of a pensions plan for the rural life style pensions research. The result is that Geumsan has a convenient traffic circumstance geographically and is a clean area as the high-level area of solid water system. Also, Geumsan forms the mountainous area whose sea-level elevation reaches to 2.5 times of the Chungcheongnam-do. Consequently, Geumsan has a suitable environment for locating many kinds of pensions like the riverside village style, the mountain village style and the villa style, the country style, the cafe style, experience style, theme style etc. So, Geumsan is found to be a suitable area to host 'rural life style' pensions, because it has wide area, small population and nice environmental conditions.

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