• Title/Summary/Keyword: mountainous regions

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Typhoon damage analysis of transmission towers in mountainous regions of Kyushu, Japan

  • Tomokiyo, Eriko;Maeda, Junji;Ishida, Nobuyuki;Imamura, Yoshito
    • Wind and Structures
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    • v.7 no.5
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    • pp.345-357
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    • 2004
  • In the 1990s, four strong typhoons hit the Kyushu area of Japan and inflicted severe damage on power transmission facilities, houses, and so on. Maximum gust speeds exceeding 60 m/s were recorded in central Kyushu. Although the wind speeds were very high, the gust factors were over 2.0. No meteorological stations are located in mountainous areas, creating a deficiency of meteorological station data in the area where the towers were damaged. Since 1995 the authors have operated a network for wind measurement, NeWMeK, that measures wind speed and direction, covering these mountainous areas, segmenting the Kyushu area into high density arrays. Maximum gusts exceeding 70 m/s were measured at several NeWMeK sites when Typhoon Bart (1999) approached. The gust factors varied widely in southerly winds. The mean wind speeds increased due to effects of the local terrain, thus further increasing gust speeds.

Estimation of DNN-based Soil Moisture at Mountainous Regions (DNN 회귀모형을 이용한 산악 지형 토양수분 산정)

  • Chun, Beomseok;Lee, Taehwa;Kim, Sangwoo;Kim, Jonggun;Jang, Keunchang;Chun, Junghwa;Jang, Won Seok;Shin, Yongchul
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.5
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    • pp.93-103
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    • 2020
  • In this study, we estimated soil moisture values using the Deep Neural Network(DNN) scheme at the mountainous regions. In order to test the sensitive analysis of DNN scheme, we collected the measured(at the soil depths of 10 cm and 30 cm) soil moisture and DNN input(weather and land surface) data at the Pyeongchang-gun(relatively flat) and Geochang-gun(steep slope) sites. Our findings indicated that the soil moisture estimates were sensitive to the weather variables(5 days-averaged rainfall, 5 days precedent rainfall, accumlated rainfall) and DEM. These findings showed that the DEM and weather variables play the key role in the processes of soil water flow at the mountainous regions. We estimated the soil moisture values at the soil depths of 10 cm and 30 cm using DNN at two study sites under different climate-landsurface conditions. The estimated soil moisture(R: 0.890 and RMSE: 0.041) values at the soil depth of 10 cm were comparable with the measured data in Pyeongchang-gun site while the soil moisture estimates(R: 0.843 and RMSE: 0.048) at the soil depth of 30 cm were relatively biased. The DNN-based soil moisture values(R: 0.997/0.995 and RMSE: 0.014/0.006) at the soil depth of 10 cm/30 cm matched well with the measured data in Geochang-gun site. Although uncertainties exist in the results, our findings indicated that the DNN-based soil moisture estimation scheme demonstrated the good performance in estimating soil moisture values using weather and land surface information at the monitoring sites. Our proposed scheme can be useful for efficient land surface management in various areas such as agriculture, forest hydrology, etc.

Depvlopment of the Evaluation Model of Location Suitability for Protected Horticulture by AHP Method (AHP기법을 이용한 시설원예의 적지평가모델 개발)

  • 황한철;김정식
    • Proceedings of the Korean Society of Rural Planning Conference
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    • 1998.10a
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    • pp.9-11
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    • 1998
  • It is necessary to evaluate the location suitability of protected horticulture facilities to guide and/or plan new protected horticulture facilities in rural areas.0 this study, as one of methodological approaches for objective and systematic evaluation for location suitability of protected horticulture, the evaluating model for location suitability of protected horticulture was formulated using AHP (Analytic Hierarchy Process) as the base technique. The evaluation model was made in three different selected regions; suburban, plain, and mountainous. The results showed that there were significant differences in evaluation model of location suitability for':ed horticulture among the three regions.

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Efficient Disaster Response Plan for Tunnel Fire Safety (터널 화재안전에 대한 효율적 재난대응 방안)

  • Jeong-Il Lee
    • Journal of the Korea Safety Management & Science
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    • v.26 no.2
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    • pp.55-64
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    • 2024
  • As the distribution of vehicles and logistics increases due to the development of human civilization and the increase in population, various roads play an important role in domestic traffic and transportation. However, the recent emergence of large cities and new cities is causing traffic problems, and the increase in roads is inevitable for the smooth distribution of vehicles and logistics. In Korea, mountainous regions occupy 70% of the country, so tunnels are used to open roads. Without this, it is difficult to open the road. Currently, there are 3,720tunnels (as of December 31, 2023) installed on high-speed national highways, general national highways, and local roads nationwide, with a length of 2.499 and increasing every year. Accordingly, fire accidents in tunnels will also increase, and due to the nature of tunnel fire accidents, there is a high probability that they will escalate into large-scale disasters, resulting in casualties and property damage, as well as significant social losses due to the disruption of logistics transportation, etc. As the possibility of potential hazards is increasing, the purpose of this study is to build a safe and efficient tunnel system by optimizing maintenance and management for fire and disaster accidents in tunnels.

Change in settlement conditions of mountain area in Chungcheong region over a 10 year period : categorization of mountain villages

  • Lee, Bo-Hwi;Kim, Se-Bin;Kim, Uhn Soon
    • Korean Journal of Agricultural Science
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    • v.43 no.1
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    • pp.40-51
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    • 2016
  • This study analyzed settlement condition changes of Chungcheong region's mountain area during 10 years, from 2001 to 2012. We performed factor analysis and cluster analysis of data from the 'Census for Mountain Area' carried out by the Korea Forest Service in 2001 and 2012. Factors 1, 2, 3, and 4 represent 'the superiority of non-agricultural income', 'the industrialized mountainous area', 'residential conveniences and benefits', and 'the use of forest resources', respectively. Clusters 1, 2, 3, 4, and 5 are categorized as 'non-agricultural income', 'various mass social functions', 'production of forest products', 'industrialized mountainous region', and 'ordinary mountain region', respectively. We suggest that cluster 1 has potential for development and should be promoted as a possible tourist attraction by digging up geographically unique themes. Cluster 2 has great potential for development and needs planned management through the maintenance or expansion of existing infrastructure. Cluster 3 has potential for development with various high value added industries uncovered. Cluster 4 shows vitality as it holds plenty of more job opportunities than other regions. Cluster 5 is deteriorating as a mountainous region because of an aging population, and it urgently demands development. For a decade, 45 of the 60 regions belonged to a single category, which are now differentiated broadly into two types: Firstly, deterioration changes to potential development and Secondly, vitality is differentiated into potential development and deterioration.

Equivalent static wind loads analysis of tall television towers considering terrain factors of hilltops based on force measurement experiment

  • Ke, Shitang;Wang, Hao;Ge, Yaojun;Zhao, Lin;Cao, Shuyang
    • Structural Engineering and Mechanics
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    • v.63 no.4
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    • pp.509-519
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    • 2017
  • Wind field in mountainous regions demonstrates unique distribution characteristic as compared with the wind field of the flat area, wind load and wind effect are the key considerations in structural design of television towers situated in mountainous regions. The television tower to be constructed is located at the top of Xiushan Mountain in Nanjing, China. In order to investigate the impact of terrain factors of hilltops on wind loads, firstly a wind tunnel test was performed for the mountainous area within 800m from the television tower. Then the tower basal forces such as bending moments and shear strength were obtained based on high frequency force balance (HFFB) test. Based on the experiments, the improved method for determining the load combinations was applied to extract the response distribution patterns of foundation internal force and peak acceleration of the tower top, then the equivalent static wind loads were computed under different wind angles, load conditions and equivalent goals. The impact of terrain factors, damping ratio and equivalent goals on the wind load distribution of a television tower was discussed. Finally the equivalent static wind loads of the television tower under the 5 most adverse wind angles and 5 most adverse load conditions were computed. The experimental method, computations and research findings provide important references for the anti-wind design of high-rise structure built on hilltops.

Applicability evaluation of radar-based sudden downpour risk prediction technique for flash flood disaster in a mountainous area (산지지역 수재해 대응을 위한 레이더 기반 돌발성 호우 위험성 사전 탐지 기술 적용성 평가)

  • Yoon, Seongsim;Son, Kyung-Hwan
    • Journal of Korea Water Resources Association
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    • v.53 no.4
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    • pp.313-322
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    • 2020
  • There is always a risk of water disasters due to sudden storms in mountainous regions in Korea, which is more than 70% of the country's land. In this study, a radar-based risk prediction technique for sudden downpour is applied in the mountainous region and is evaluated for its applicability using Mt. Biseul rain radar. Eight local heavy rain events in mountain regions are selected and the information was calculated such as early detection of cumulonimbus convective cells, automatic detection of convective cells, and risk index of detected convective cells using the three-dimensional radar reflectivity, rainfall intensity, and doppler wind speed. As a result, it was possible to confirm the initial detection timing and location of convective cells that may develop as a localized heavy rain, and the magnitude and location of the risk determined according to whether or not vortices were generated. In particular, it was confirmed that the ground rain gauge network has limitations in detecting heavy rains that develop locally in a narrow area. Besides, it is possible to secure a time of at least 10 minutes to a maximum of 65 minutes until the maximum rainfall intensity occurs at the time of obtaining the risk information. Therefore, it would be useful as information to prevent flash flooding disaster and marooned accidents caused by heavy rain in the mountainous area using this technique.

Curve Number for a Small Forested Mountainous Catchment (산지 소유역 유출곡선지수)

  • Oh, Kyoung-Doo;Jun, Byong-Ho;Han, Hyung-Geun;Jung, Sung-Won;Cho, Young-Ho;Park, Soo-Yun
    • Journal of Korea Water Resources Association
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    • v.38 no.8 s.157
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    • pp.605-616
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    • 2005
  • In this paper, runoff curve numbers (CN's) for a small forested mountainous catchment are estimated using rainfall-runoff data measured at Sulma experimental catchment every 10 minutes and a new guideline for applying the antecedent rainfall conditions (ARC's) for small mountainous watersheds in Korea is proposed. Sulma experimental catchment is a typical natural mountainous basin with $97\%$ of forested land cover and CN's are estimated to be in the range between 51 and 89 with median value of 72. The test hypothesis stating as 1-day ARC is better than 5-day ARC in determining CN's for a small mountainous watershed is shown to be acceptable. Also, linear regression equations for the estimation of CN's for small mountainous catchments are proposed. As there is no significant investigations available on CN's for small mountainous catchments, the newly proposed relationships between CN's and ARC may be used as a preliminary guideline to assign CN's for the estimation of floods from rainfall data on mountainous regions.