• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.45-54
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• 2001

This study was carried out to provide fundamental data for prospective forest-road project and forest-road network arrangement through appraising existing forest-road network with density, extension distance, maximum yarding distance and yarding area, position of forest-road line considered above foundation of two theories, one is "theory of optimal forest-road density" which has expense for yarding cost and constructing forest-road minimized, the other is "theory of optimal forest-road arrangement" which has investment effect maximized. The results are as follows. 1. In density and extension distance of the forest-road by site, it was showed up that density of existing forest-road is lower than that of calculated forest-road. So, it is thought that some additional forest-roads have to be constructed. 2. In the arrangement of the forest-road network by site, it was showed up that the arrangement of calculated forest-road is higher than that of existing forest-road arrangement for the forestry and yarding function. So, it is thought that the arrangement of forest-road network have to be considered to maximize the investment effect. 3. In "mean maximum distance for yarding" and "mean area which yarding can be done" by horizontal and inclined distance, the existing forest-road networks were different from those of calculated forest-road network. So, calculated forest-road network making investment effect maximize is more effective than existing forest-road network. Hence, in prospective forest-road project, it is needed that forest-road network having "area which yarding can be done" maximized through considering function for yarding have to be constructed.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.239-252
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• 1998

Based on forestry inventory data and various informations, this study was conducted to analyze the silvicultural activities by distance classes from forest road and to evaluate their effects in the area of Mt. Gari managed by Chunchon Regional Office of Northern Forest Management Office. The results were summarized as follows; 1) Most harvesting practice(67.9%) was done within 500m from forest roads, in the order of Pumgul, Saorang, and Kongkol forest road. And thinning practice was not related to the distance from forest road, produced $440.6m^3$, 35.7% of total thinning volume within 1,000m width along the forest roads. 2) Planting of 530,461 seedlings, 66.8% of total planting stock, in 176.9ha, 66.6% of total area within 1,000m from forest road, and supplementary planting of 46,243 seedlings was done in 15.4ha, 42.9% of total area within 500m from forest road. Areas and numbers of seedlings of two planting practices were in the order of Pumgul and Byungatur forest road. 3) Tending operation was done in 330.0ha, 60.3% of total area within 500m from forest road, and pre-commercial thinning was done in 693.6ha, 71.2% of total area. Areas of intermediate cutting practices were in the order of Pumgul, Korkol, and Saorang forest road.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.449-455
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• 2016

This study was conducted to provide the basic policy information for systematic forest road planning and maintenance management by surveying two different administrator groups. The survey results showed that the high priorities of forest road planning were silviculture, disaster prevention, and timber harvesting, and main forest road type was preferred for future use. Also 92.9% of the respondents expressed difficulties due to insufficient manpower and budget. The expected damage types due to forest road construction were threat-to-life by slope failure and dispute on crossing private land. The current main maintenance tasks on forest roads included drainage and road surface maintenance works. Main forest road facilities that should be needed after the construction were installation of additional drainage structures, and slope revegetation and stabilization.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.73-83
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• 2022

The factors influencing landslide occurrence were analyzed for six points on the upper slope and the 24 points on the lower slope along a forest road around Sangsan village in Chungju, Korea, where landslides have occurred due to heavy rainfall. In terms of physico-mechanical properties of the soil layer, the lower slope seemed to loosen owing to the higher porosity, lower unit weight, and lower friction angle compared with the upper slope. With respect to topographic characteristics, the lower slope had thicker regolith, more concave profile and plan curvatures, lower slope angles, and higher topographic wetness index values than the upper slope. Therefore, all the properties (except for the slope angle) appear to make the lower slope of the forest road more vulnerable to landslides than the upper slope. Apart from the physico-mechanical and topographic characteristics, inadequate maintenance and management of drainage facilities are also considered as further major factors influencing landslide occurrence.

• Korean Journal of Environment and Ecology
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• v.32 no.4
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• pp.392-412
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• 2018

This study was conducted from 2012, which was a year before forest road construction in Minjujisan, to 2015 to verify effects on flora and vegetation change annually before and after the construction, and to provide strategies to examine and manage flora changes. The plant communities in the investigated area around the forest road is separated by the slopes into Quercus mongolica community is on the northwestern slope and Quercus variabilis and Larix kaempferi communities is on the southwestern slope. The annual investigation of flora change before and after the construction showed that there were 209 taxa that had 71 families, 153 genera, 178 species, 27 varieties, and 4 forma in 2015 while there were 66 taxa that had 44 families, 59 genera, 51 species, 13 varieties, and 2 forma in 2012 before the construction, indicating an increase of 143 texa before and after the construction. The investigation of the slope area adjacent to the forest road constructed in 2013, in particular, showed increasing coverage and taxa each year after the construction. This was caused by significantly increased light transmittance after the construction. The investigation in 2015 showed increased coverage of herbaceous layer the year after development of the forest road and the remarkable increase of the coverage of shrub layer in 2015. Further, the coverage on the slope adjacent to the forest road increased more in 2015 than in 2013 and 2014. Therefore, we expect supplementary studies will help to generate a detail manual on flora and vegetation change before and after forest road construction.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.615-621
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• 2015

This study was conducted to analyze accessibility and reduction effect of forest operations cost before and after forest road construction based on actual silvicultural operations in 5 regional forest service(8 management planning district) where forest operations was enacted consistently. The result show the accessibility and the reduction effect of the operation cost, the accessibility of forest operation area within 500 m from forest road or public road increased about 3.2 times after the forest road construction. The reduction effect of the operation cost was averagely 576,000 won/km/year. According to the results, forest road had an effect on improvement of accessibility and reduction effect of forest operation cost. This result could be offered basic information to support policy of forest road expansion.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.326-327
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• 2000

May(1945)에 의하여 임팩터가 개발된 이후 임팩터의 단별 분리입경의 정확성을 증가시키고, 기판에서 입자의 채취량을 늘리며, 임팩터 내부의 입자손실과 기판에서 입자가 충돌하여 튀어나오는 것(bounce)을 줄일 수 있는 방법 등이 꾸준히 연구되고 있다. 가속 노즐의 형상을 사각형에서 원형으로 변경하여 분리효율곡선의 기울기(stiffness)를 증가시킬 수 있었고(Mitchell and Filcher, 1959), 임팩터의 한 단에 여러 개의 가속 노즐을 가공한 다중 노즐(multi-jet) 임팩터를 사용함으로써 단의 분리입경을 낮추고, 입자의 채취량을 늘릴 수 있게 되었다(Anderson, 1958). (중략)

• Journal of Korean Society of Forest Science
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• v.84 no.3
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• pp.319-332
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• 1995

This research was carried out to investigate the influences of forest road characteristics and rainfalls on the amount of erosion on the newly - constructed forest road in the Research Forests of Seoul National University located in Mt. Backwoon - san, Kwangyang. Amount of soil erosion on the newly - constructed forest road was measured for 2 years since the forest road construction. Using the stepwise multiple regression method, amount of soil erosion from cut - slopes, fill - slopes, road surfaces, and side - ditches were seperately expressed as a function of statistically significant road design and rainfall factors, and multiple regression models to estimate the amount of soil erosion were significant to explain the variance in erosion by each structures. According to results of this study, amount of erosion from the newly - constructed forest road was estimated as much as 668.51m/km for 2 years. Out of total amount of soil erosion, 21.9%(144.27m/km) from cut - slopes, 39.8%(261.89m/km) from fill - slopes, 8.1%(53.33m/km) from road surfaces, and 30.2%(199.02m/km) from side - ditches were occurred.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.367-391
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• 2023

This study was conducted for 10 years from 2012, which is a year before the forest road construction in Minjujisan, to 2022 to analyze annual changes in flora and vegetation before and after the forest road construction and to provide strategies for management. The plant communities in the research sites along the forest road showed the differentiation between slopes with Quercus mongolica community on the northwestern slope and Quercus variabilis and Larix kaempferi communities on the southwestern slope. A total of 212 taxa have increased for number 7 between before and after the construction from a total of 66 taxa (44 families, 59 genera, 51 species, 13 varieties, and 2 forma) in 2012 and 207 taxa (71 families, 153 genera, 176 species, 27 varieties, and 4 forma) in 2015 to 278 taxa (78 families, 172 genera, 242 species, 1 subspecies, 31 varieties, and 4 forma) in 2022. It is noteworthy that the vegetation cover and the introduction of new taxa had been expanded in the sites adjacent to the construction, which is likely caused by the significantly increased amount of light and the introduction of annual herbaceous and naturalized plants after the construction. The results of 10 years of current study reveal that the vegetation cover and the number of new taxa had rapidly increased in earlier years after the construction, slowly decreased later on, and finally formed a stable forest with the increase in the ratio of dominant species. The vegetation cover of the herbaceous layer immediately increased on the slopes along the forest road for a few years after the construction although it had continuously decreased while that of the shrub layer quickly increased. It was shown that on the hillslope the vegetation cover of tall- and low-tree layers increased whereas that of herbaceous and shrub layers rapidly decreased.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.477-484
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• 1999

This study was conducted to investigate the effect of forest road on the suspended sediment yield into a stream in the small forest watershed. The samples of suspended sediment yield were collected at surveying points A and B in mountains watersheds unaffected by forest road, and at surveying point C affected by forest road. When hourly change of suspended sediment concentration was investigated, it showed the highest increase along the forest road, and the peak of suspended sediment concentration due to the watershed characteristics of each surveying point occurred before or at the same time with, the peak of discharge. This may be due to the time lag in which stagnated unstable suspended sediment moved strongly upon rainfall. Although suspended sediment load varied depending upon rainfall factors and surveying period, suspended sediment load per unit watershed flowed out 4.1 times more at the point C than at the point A and B. The suspended sediment load on 18~19 September, 1998, strongly affected by rainfall factors, was 4.179g/sec/㏊ at the point C, and 0.343g/sec/㏊ and 0.147g/sec/㏊ at the point A and B, respectively. This load was 12 times higher at the point C than at the point A and 28 times higher than at the point B.