• Title/Summary/Keyword: national forest road

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A Study on Landslide in the Slope of the Forest Road (임도사면(林道斜面)의 붕괴(崩壞)에 관(關)한 연구(硏究))

  • Oh, Jae-Man;Chun, Kun-Woo
    • Journal of Forest and Environmental Science
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    • v.7 no.1
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    • pp.35-41
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    • 1990
  • This study was conducted to find out the suitable gradient and length of the slope from the landslide of banking slope and cutting slope caused by rainfall. The survey was carried out on forest road built in 1986. And the period of survey was from June, 1989 to August, 1989 after dividing the forest road into A and B. The survey plots consisted of the 12 banking slopes and 6 cutting slopes. The results obtained from the study were summarized as follows; 1. The rate of landslide appeared 75% in A forest road, 50% in B forest road, and then the average 67% in A and B forest road. But the value of landslide showed considerably low. 2. Because of landslide chiefly occuring on banking slope of $36^{\circ}{\sim}38^{\circ}$ and on cutting slope of $42^{\circ}{\sim}43^{\circ}$, it is suitable to decide the banking slope and cutting slope below each $36^{\circ}$ and $40^{\circ}$. 3. Landslide was the same on banking slopes through the length of slope. The best suitable length of slope is below 4m in cutting slope.

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Analysis of Some Desert Ecosystems Vegetation in Abu Dhabi Emirate, United Arab Emirates. Effect of Land Use

  • Mousa, Mohamed Taher;Ksiksi, Taoufik Salah
    • Journal of Forest and Environmental Science
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    • v.25 no.1
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    • pp.49-55
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    • 2009
  • The present study analyses the effect of land use on the vegetation of some desert ecosystems in Abu Dhabi, United Arab Emirates (UAE). Three sites were selected to represent different types of land use, inside Umm Al-Banadeq forest, outside the forest and along Abu Dhabi-Al Ain Trucks Road. In total, fifty-two stands were examined; including a matrix of 14 species ${\times}$ 52 stands. Based on species cover data, stands were classified using TWINSPAN and ordinated using DCA. Four vegetation groups were generated at level three of classification. Zygophyllum mandavillei was dominant in most vegetation groups; Heliotropium bacciferum dominated vegetation groups inhabited the forest. Species richness, species turnover, relative evenness and relative concentration of dominance of forest vegetation groups were 2.8, 5.7, 0.7, and 2.0, respectively. The differences were attributed to both natural variability and forestry-induced changes, including change in land use, drainage and ploughing and shading by trees. Vegetation group inhabited Abu Dhabi-Al Ain Trucks Road, that were dominated by Haloxylon salicornicum and Zygophyllum mandavillei have high total cover (8.8 m per $m^{-1}$). Most community and vegetation attributes were significantly higher inside the forest than outside. Human interventions and environmental factors affected species diversity and abundance of these communities.

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Recent Trends of Forestry Economics and its Problems in Japan (최근(最近) 일본(日本)의 임업경제(林業經濟) 동향(動向)과 임업(林業)의 과제(課題))

  • Park, Myeong Kyu
    • Journal of Korean Society of Forest Science
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    • v.46 no.1
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    • pp.70-76
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    • 1980
  • Forestry economics in Japan faces the problems of severe decreasing of timber demand and increased importing of foreign timber. Moreover, lack of labour and heavy wages in forestry cause the failure of normal forest management in Japan. In the situation, it is necessary for enhancing the forest production to reorganize the forest resources, to optimize the amount of importing foreign timber, and to greatly expand the new forest road, reforestation, government subsidy and poritical financial support for the foresters. At present, improvement of mangement of national forest as well as public function of forest are being discussed for the forest production on the government basis.

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Analyses of Forest Road Construction Policy Using LISREL Approach (리즈렐모형을 이용한 임도사업의 계량적 분석)

  • Choi, Kwan
    • Journal of Korean Society of Forest Science
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    • v.97 no.1
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    • pp.22-29
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    • 2008
  • The objective of this study is to provide useful information for the establishment of efficient policy implementation strategies of forest road construction policy in South Korea. Data needed for the analysis was collected by a questionnaire survey. For the analysis, policy evaluation model was constructed based on theories of public policy. Evaluation model contains three independent variables (policy initiative factor, policy content, policy environment) and two dependent variables (policy result, policy impact). Since, these variables are unobservable latent variables, observable indicators are needed as proxy measures. LISREL (Linear Structural Relationships) was employed for the analysis since it is a useful measure for analysing linear structural model which consists of structural and measurement equations. It was confirmed that forest road construction is an effective policy mean for the development of rural region and activating forest resources management. The policy outcome, however, was not satisfactory. To improve the effectiveness of forest road construction policy some modification of policy contents are needed such as increased construction budget, allowing more flexibility and participation to the implementation personal and providing technical support.

Changes in Forest Disturbance Patterns from 1976 to 2005 in South Korea

  • Park, Pil Sun;Lee, Kyu Hwa;Jung, Mun Ho;Shin, Hanna;Jang, Woongsoon;Bae, Kikang;Lee, Jongkoo;Lee, Don Koo
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.593-601
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    • 2009
  • Forest disturbances including forest fire, insect pests and diseases, landslides, and forest conversion from 1976 to 2005 were investigated to trace the changes of major forest disturbance agents and their characteristics over time in accordance with changes in natural and social environment in South Korea. While the damaged area by insect pests and diseases continuously decreased for the past 30 years, damaged areas by forest fire and landslide were fluctuating through years. The interval of large forest fires has become shorter with increased tree volume. The precipitation between January and April were significantly correlated with large fire occurrences as Pearson's correlation coefficient -0.400 (P=0.029). The composition of major insect pests and diseases damaging Korean forests has been changed continuously, and become more diversified. While damages by pine caterpillar (Dendrolimus spectabilis) and pine needle gall midge (Thecodiplosis japonensis) decreased, damage by introduced pests has been more serious recently. The change of precipitation pattern that brought more localized heavy rain or powerful typhoon resulted in the recent increase in landslide areas. The major land uses to induce forest conversion have been changed, reflecting the changes in industrial structure in South Korea as agriculture and mining in 1970s, mining and golf ranges classified in pasture in 1980s, and road and housing construction in 1990s and 2000s. Changes in forest disturbance patterns in South Korea show that a country's industrial development is jointly working with global warming on forest stand dynamics. Altering energy structure and land use pattern induced by industrial development accumulates forest volume and reforms microenvironments on forest floor, interacting with climate change, inducing shorter interval of large forest fire and changes in major species composition of forest insect pests and diseases.

Assessment of Running Speed of Large Logging Trucks on the Forest Road Structure (임도 구조에 따른 대형 목재운송차량의 주행속도 분석)

  • Hwang, Jin-seong;Lee, Kwan-hee;Ji, Byoung-yun
    • Journal of Korean Society of Forest Science
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    • v.110 no.4
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    • pp.622-629
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    • 2021
  • This study analyzed the running speed of logging trucks (25 tons), depending on the structural state of forest roads, on four main forest roads in the national forest management offices in Chuncheon and Hongcheon for trafficability. The speeds for the curved and straight sections were 7.6 km/h and 8.7 km/h, respectively, which were less than the designed speed (20 km/h). Thus, it would be necessary to improve the forest road's structure to fulfill minimum running speed. No significant difference was observed in the running speed by the longitudinal gradient up to 13%, while it was increased at more than 100 m by the distance in the straight section. By the facility's location in the curved section, the running speed was 6.2%-9.3% lower in a ridge than a valley. The running speed was lowest at the internal angles of <90° and at the curved radius of <15 m, respectively. When this radius was less than 15 m, the substandard sections for widening amounts were more than 50%; thus, sufficient widening was not achieved.

A Study on the Restoration on the Strip Roads Mt. Baekun Area (백운산 지역에서 벌채지내 운재로의 회복에 관한 연구)

  • Park, Jae-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.2
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    • pp.34-43
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    • 2007
  • To investigate the restoration procedure on soil physical properties and vegetation at the surface of strip road affected by timber harvesting operation. This study was carried out at strip roads constructed between 1989 and 1994 in Mt. Baekun, Kwangyang, Chollanam-Do. Soil hardness of the surface layer was improved with change of time after strip road construction, but that of 7.6~15 cm depth from the surface was not improved. According to linear regression analysis, it was estimated 16.6 years in 0~7.5 cm and 16.9 years in 7.6~15 cm soil depth to be restored to natural forest lands. The amount of surface soil erosion was 0.045$m^3$/km/yr on strip roads constructed in 1989 and 1990, and road constructed in 1994 showed the highest value (4.5$m^3$/km/yr). Vegetation coverage rates of road surface were 96.7% in strip roads constructed in 1990. Those of cutslope and fillslope were highest in roads constructed in 1990. The results indicated that strip roads were restored with change of time after road construction.

Characteristics of Habitat Structure and Bird Communities between a Natural Deciduous Forest and the Road Area in Gwangneung, Korea (광릉 지역 활엽수 천연림과 도로 주변의 서식지 구조와 조류군집 특성)

  • Lee, Ju-Young;Kang, Jeong-Hoon;Rhim, Shin-Jae
    • Korean Journal of Environment and Ecology
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    • v.21 no.1
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    • pp.47-54
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    • 2007
  • This study was conducted to clarify the characteristics of habitat structure and bird communities between natural deciduous forest and around the road from October 2005 to August 2006 in the National Arboretum, Gwangneung, Korea. There were more larger trees and higher coverage of crown canopy in the natural deciduous forest than around the road. A total thirty seven species of birds were observed in the natural deciduous forest and twenty species were around road. The observed number of bird species and individuals, and bird species diversity index (H') were higher in the natural deciduous forest in each season. Foraging and nesting guild structures were also different. The differences of characteristics of bird communities would be related with habitat structure between both study areas.

Evaluation of Onshore Wind Resource Potential According to the Road Proximity (도로인접성에 따른 육상 풍력자원 잠재량 평가)

  • Kim, Hyun-Goo;Hwang, Hyo-Jung;Kang, Yong-Heack;Yun, Chang-Yeol
    • New & Renewable Energy
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    • v.9 no.4
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    • pp.13-18
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    • 2013
  • Wind turbines should generally be installed at a certain distance from a road to ensure passengers' safety. In Korea, there is no clear guidance as the Ministry of Environment first proposed a road setback distance of 400 m in the Onshore Wind Farm Siting Guidelines draft proposed in July 2012, and then modified it to 1.5 times the height of the wind turbine in October of the same year. This study analyzed the dynamic range of onshore wind resource potential according to how the road setback distance is set using the Korea Wind Atlas with 100m spatial resolution made by the Korea Institute of Energy Research, the transportation network of the Ministry of Construction and Transportation, and the forest road network of the Korea Forestry Service. Owing to the geographical characteristics of Korea, where mountainous terrain accounts for 70% of the total territory, the wind resource potential within 1 km from forest roads are estimated to be 14.3 GW, 14% of Korea's total wind resource potential. In addition, the construction distance of new road for transporting wind turbines from the existing road to a wind farm site is estimated as less than 2 km. Given the limited wind resource potential and geographical constraints, an assessment system that can maximize wind resource utilization and ensure road safety at the same time, and which takes into account the regional characteristics instead of applying the fixed road setback distance across-the-road, is required.

Stabilization Method by Timber Pile for Fill Slope Failure on Forest Road (임도(林道) 성토사면(盛土斜面)의 소경재(小經材) 붕괴억지공법(崩壞抑止工法)에 관한 연구(硏究))

  • Ji, Byoung Yun;Jung, Do Hyun;Kim, Jong Yoon;Cha, Du Song
    • Journal of Forest and Environmental Science
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    • v.17 no.1
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    • pp.104-115
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    • 2001
  • This study was carried out to to execute the slope stabilization scheme of soil and weathered rock slope with forest road generating slope failure due to heavy rainfall. The timber piled stabilization by Shin's formulae for landslide-restraint pile as elastically supported elastic columns under distributed loads was applied on the unstable fill slope. The results obtained were summarized as follows: The timber piled stabilization was applied for unstable slopes such as the soil slope and weathered rock slope of metamorphic rock regions. The results indicated that pile interval of 0.5~1.0m was appropriate in the case of high hillslope gradients and 0.7~2.0m in the case of low hillslope gradients of soil slope, and Pile interval of 0.5~1.3m in the case of high hillslope gradients and 0.7~2.0m in the case of low hillslope gradients of weathered rock slope. Recommended pile length was around 4m for pile 1, 2 and 3, and nearly 3m for pile 4 and 5.

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