• Title/Summary/Keyword: national forest road

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Effect of Linear Development Projects on Forest Fragmentation in the Nakdong River Watershed (낙동강 유역의 선형개발사업이 산림 단편화에 미치는 영향)

  • Jung, Sung-Gwan;Park, Kyung-Hun;Oh, Jeong-Hak
    • Journal of Environmental Impact Assessment
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    • v.11 no.3
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    • pp.117-127
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    • 2002
  • This study tested the usefulness of landscape indices for quantifying forest fragmentation due to linear development projects. Research was carried out in the middle-upper Nakdong River watershed, which has been affected by the expressway building, or national road-widening. Landscape indices were calculated from the forest cover maps before and after road-building using FRAGSTATS 3.1. We could successfully demonstrate the forest fragmentation based on landscape indices; (1) patch size decreased, and edge density and patch density increased (2) roads simplified patch shapes, especially in the larger patches, (3) patch core area size decreased, and core area density increased, (4) the distance increased between the focal patch and each of the other patches within the search radius (=1km) as a result of roads. We suggest several important needs for future researches, including continued investigation of scaling issues, development of indices that measure specific components of spatial pattern, and study of the relationships between forest fragmentation and ecological processes.

Dominant Species and Factors Related with Plant Coverage in the Cutting Slopes of Forest Road -In Jeollabuk-do Region­- (임도 절토비탈면의 우점식물과 식물피복에 미치는 인자들의 영향 -­전라북도를 대상으로­-)

  • Park, Moon-Su
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.1
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    • pp.19-27
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    • 2002
  • To investigate the dominant species and factors related with plant coverage by road structures and forest environment factors, forest roads elapsed from one year to twelve year after construction had been selected in six county(Gochang-gun, Muju-gun, Imsil-gun, Jangsu-gun, Jeongup-shi and Jinan-gun), and 20m segments were continuously set up in each road. The results obtained from this study are summarized as follows: The species diversity of Gochang, Muju, Imsil, Jangsu, Jeongup and Jinan were 1.304, 1.267, 1.308, 1.193, 1.289 and 1.018, respectively. In process of years, plant coverage was increased gradually and average of plant coverage was 15.3% in forest roads which elapsed three year, and was 86.5% in forest roads which elapsed nine year after construction. The dominant species in the cutting slope of surveyed area were covered with Arundinella hirta, Pinus rigida, Miscanthus sinensis var. purpurascens, Artemisia princeps var. orientalis, Pinus densiflora, Oplismenus undulatifolius, Rubus coreanus, Lysimachia clethroides, Lespedeza bicolor, and Alnus hirsuta of the 152 species. The high correlated factors between plant coverage and variables in cutting slopes appeared elapsed year, soil hardness, mean annual precipitation, vertical grade, inslope and arid humidity in surveyed area.

The Techniques Development for the Possibility Area Analysis of Yarding Operation and the Forest-road Network Arrangement using GIS (GIS를 이용한 집재작업 가능구역 분석 및 노망배치를 위한 기법 작성)

  • Kwon, Hyun-Jung;Park, Sang-Jun
    • Journal of Korean Society of Forest Science
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    • v.102 no.1
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    • pp.143-155
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    • 2013
  • In order to establish efficient timber harvesting system and provide the necessary data for the system establishment, the techniques to identify areas possible of the yarding-operation and design forest-road networks were newly developed and the applicability of the techniques are tested in this study. The new techniques were developed based on ArcGIS, particularly with utilizing the Viewshed Analysis Tool. From the results of the identification of the possible yarding-operation areas, it is found that the percentage of possible yardingoperation area decreases with the increment of maximum yarding distance due to terrestrial effects. When forest road networks are extended in impossible yarding-operation sites, the area of possible yarding-operation sites increases. If a forest road network is newly designed, its overall extension is altered, resulting in changes in the possible yarding-operation areas. Through the comparative analysis among the different possible yardingoperation areas from different forest road networks, the maximization of the yarding-operation possible area can be achieved. The results from this study can be utilized for establishing more efficient timber-harvesting system and developing GIS-based programs to manage the system.

Changes in Temperature and Humidity in the Forest Caused by Development (도로에 의한 산림 내 온습도 변화)

  • Choi, Jaeyong;Park, Myung-Soo;Kim, Su-Kyung;Yu, Seung-Hyeon;Choi, Won-Tae;Song, Wonkyong;Kim, Whee-Moon;Kim, Seoung-Yeal;Lee, Ji-Young
    • Journal of Environmental Impact Assessment
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    • v.27 no.6
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    • pp.604-617
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    • 2018
  • As the depletion of forests became more widespread due to the increase in the number of roads, the research was conducted on the relationship between temperature and humidity in the forests, assuming that the forests around the roads were affected. Through the forest monitoring, the temperature and humidity of coniferous forests and broadleaf forests in Sedong and Gongju areas were observed at three point of 10m, 20m and 30m from the road boundary to the inside of the forest, respectively. In Yeongdong area, for more reliable results, it was observed from the point of 0m, 10m, and 20m. During the study period, so it was expected the change in tree growth was small, the change of temperature and humidity inside the forest by the road was compared with the temperature and humidity from the road to the inside of the forest from September 2017 to January 2018, the changes of temperature and humidity inside the forest due to linear development such as roads were quantitatively analyzed. Using the HOBO data logger (MX2301, Onset Corp.), the temperature and humidity changes of each site were measured, and the average of the changes have been analyzed monthly. In the case of Gongju coniferous forests in September 2017, the average weekly temperature is $0.57^{\circ}C$ higher than the forest outside from the forest boundary and $1.23^{\circ}C$ higher than the inside of the forest, at night in November 2017, in Sedong broadleaf forests. That is, the ability to control the temperature and humidity of the forests along the road was larger and less variable as the distance from the road boundary to the inside of the forest increased. In this study, it is considered that the high degree of change in temperature and humidity of the forest and the surrounding area due to artificial linear development such as roads will affect the growth of trees. This results could serve as a basis for studying the quantitative scope of linear development affecting forest growth and for managing forest change caused by linear development.

Determination of Forest Road Construction Priority Order using Concordance Analysis (Concordance Analysis를 이용한 임도개설의 순위결정에 관한 연구)

  • Cha, Du-Song;Kim, Jong-Yoon;Jung, Do-Hyun;Ji, Byoung-Yun
    • Journal of Forest and Environmental Science
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    • v.13 no.1
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    • pp.96-103
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    • 1997
  • By the means of concordance analysis among scoring methods, this study was to determine the priority order of forest road construction in 11 areas. The results have shown that the priority order by concordance index was ranked by area 9, 5, 11, 10, 6, 1, 3=4, 2, 7 and 8, and that by dis-concordance index by area 9, 3, 4, 5, 10, 8, 1, 11, 6, 7 and 2.

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Preliminary Analysis of Stabilization of Forest Road Surface Using Geosynthetics (토목섬유를 이용한 임도 노면의 안정성 예비 분석)

  • Lee, Kwan-Hee;Oh, Se-Wook;Ko, Chi-Ung;Kim, Dong-Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.6
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    • pp.51-60
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    • 2015
  • This study conducted shear strength test and plate bearing test to look into the characteristics of bearing capacity using geosynthetics case on forest road surface. The shear strength test showed that the internal friction angle at the time when geosynthetics was used was measured larger on average than that in the unreinforced case. Therefore, using geosynthetics case produced more bearing capacity reinforcement effect. The result from the comparison test of internal friction angle by geosynthetics type revealed that the internal friction angle at the time when geotextile case was used was measured larger. That was attributable to the difference between the area of the total cross section of geotextile made in type of non-woven fabric and its material. Plate bearing test showed that the settlement at the time when geosynthetics was used was measured smaller than that in the unreinforced case. Therefore, using geosynthetics produced more bearing power reinforcement effect. The result from the comparison test showed that geogrid case was measured smaller than geotextile case. Henceforth, It is seemed that it will be necessary to keep studying the reinforcement engineering and process of forest road surface which fits the characteristics and conditions of geosynthetics to prevent forest road demage.

Analysis of Bearing Capacity Change of Forest Roadbed by Opening Year (개설시기에 따른 임도 노반의 지지력 변화분석)

  • Chen, Hyeong-Uk;Kim, Dong-Hyeon;Lee, Kwan-Hee;Kim, Dong-Geun
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.322-328
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    • 2019
  • The purpose of this study was to provide basic data for maintenance and repair of the forest road surfaces using the light drop weight test (LDWT), density test, and grain size analysis at four sites in Yeongyang-gun Mt. (2011y, 2014y, 2016y, and 2017y). In terms of the density test results, the opening density in 2011 was the highest at $2.0694g/cm^3$, and the opening density in 2017 was the lowest at $1.7443g/cm^3$. The grain size analysis showed that the proportion of large aggregates was highest at the opening in 2017, and the proportion of large aggregates decreased with the delay of opening date. From the LDWT results, $E_{vd}$ (the dynamic deformation coefficient) of the 2011y forest road was $35.7MN/m^2$, 2014y was $30.5MN/m^2$, 2016y was $28.6MN/m^2$, and 2017y was $23.5MN/m^2$. The $E_{vd}$ value for the oldest forests opened with the 2011y forest road was the highest, the average $E_{vd}$ value of the center portion was $21.45MN/m^2$, the average $E_{vd}$ value of the wheel portion of the banking part was $31.31MN/m^2$, and the average $E_{vd}$ value of the wheel portion of the cut part was $36.71MN/m^2$.

Soil Mechanical Properties for Fill Slope of Forest Road in Mt. Gari (춘천(春川) 가리산(加里山) 지역(地域)의 임도(林道) 성토사면(盛土斜面)의 토질역학적(土質力學的) 특성(特性))

  • Cha, Du Song;Chun, Kun Woo;Ji, Byoung Yun;Oh, Jae Heun
    • Journal of Forest and Environmental Science
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    • v.15 no.1
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    • pp.98-106
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    • 1999
  • This study was carried out to analyze the mechanical properties of soil for counterplan of recovery construction and the slope stability on fill slope of Sang-gul forest road in Mt. Gari. To analyze the mechanical properties of apparent soil on fill slope in forest road, various soils such as soil, gravelly sandy soil, weathered rock were used as experimental sample in this study. In each experimental sample, particle size distribution test, liquid limit test, plastic limit test, and specific gravity test were carried by Korean industrial standards(KS F 2302, KS F 2303, KS F 2304, KS F 2306, KS F 2308). Through the results of soil particle size distribution analysis, soil moisture content analysis, and specific gravity analysis, soil texture, uniformity coefficient, curvature coefficient, dry density and specific gravity were able to be determined in sampling site. As a results in this study, soil was classified as SP, SW, GP by Unified Soil Classification Standard (USCS). specific gravity and dry unit weight of soil have the value range of 2.52~2.60 and 1.39~1.43, respectively. Also plastic index showed non plastic condition.

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Analysis of Spatial Patterns and Estimation of Carbon Emissions in Deforestation using GIS and Administrative Data (GIS와 행정정보를 이용한 교토의정서 제3조 3항 산림전용지의 공간패턴 및 탄소배출량 분석)

  • Lee, Jung-Soo;Park, Dong-Hwan
    • Journal of Forest and Environmental Science
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    • v.27 no.1
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    • pp.39-46
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    • 2011
  • This study purposed to analyze the spatial pattern and the amount of carbon emission at the deforestation area in Gangwondo. Forest geographic information system(FGIS) and administrative data were used in the analysis. The area size and spatial patterns of deforestation area were analyzed according to the article 3.3 of Kyoto protocol. Forest administration data for 9 years from 2000 to 2008 were entered into a database. Fifty-nine percent of deforestation area was found within 200m of the road network, and seventy-five percent of the area was found within 500m. Theoretical carbon emission based on deforestation area was estimated at 6,968tc. Carbon emission of national forest was 5.7times higher than that of private forest.

Evaluation of Slope Failure Possibility on Forest Road Using Fuzzy Theory(I) - On the Fill Slope of the Metamorphic Rock Area - (Fuzzy이론(理論)을 이용(利用)한 임도사면(林道斜面)의 붕괴가능성(崩壞可能性) 평가(評價)(I) - 변성암지역(變成岩地域)의 성토사면(盛土斜面)을 중심(中心)으로 -)

  • Cha, Du Song;Ji, Byoung Yun;Oh, Jae Heun
    • Journal of Korean Society of Forest Science
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    • v.89 no.1
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    • pp.33-40
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    • 2000
  • This study was carried out to evaluate the fill slope failure possibility of forest road in Metamorphic rock area using fuzzy theory which is non-linear model. The results were summarized as follows. The potential slope failure by nine factors was mainly occurred under the such conditions as the total road width ranging from 4m to 5m, longitudinal gradients below $2^{\circ}$, fill slope length greater than 8m, fill slope gradients steeper than $40^{\circ}$, road on ridge position, soil types with weathered rock, slope gradients steeper than $40^{\circ}$, aspect of NW, and longitudinal slope form in convexity. The weight of importance by factors on fill slope failure was ranked in the order of fill slope length, fill slope gradient, road position, soil type, aspect and longitudinal slope form. The analysis showed that the fill slope failure possibility was low with less than 0.485 of the fuzzy integral value and high with more than 0.620 of the value. And the discriminant accuracy was 74.6%. The analysis with six out of nine factors indicated that the possibility was low with less than 0.441 of the fuzzy integral value and high with more than 0.583 of the value. In this case, the discriminant accuracy was slightly increased to 78.0%.

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