• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.206-212
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• 2015

This study was carried out to assess the characteristics of gabion on road cut-slopes, and analyze the scenic view preference for the gabion in Korea. 97 gabion sites from road cut-slopes were selected and were classified into 10 application types of gabion. The classification types of gabion were mostly related to the erosion and collapse prevention across road cut-slope. Gabion work sites in this study were classified into 30 sites (31%) for below 10% gradient, followed by 31 sites (32%) for 11~30% gradient, 20 sites (21%) for 31~50% gradient, and 16 sites (16%) for 51~80% gradient. Gabion works were constructed mostly in low gradient than in high gradient. 34 gabion sites (35%) among 97 sites were not covered by vegetation and 52 gabion sites (54%) showed vegetation cover rates of 1~30%. On the scenic preference analysis, public groups understood that the scenic view of gabion in cutting slope can be improved by vegetation cover, whereas expert groups prefer to scenic view of gabion only. However, expert groups encouraged subsequently vegetation covering to improve scenic view during gabion works in cutting slope.

• Tunnel and Underground Space
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• v.20 no.1
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• pp.15-27
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• 2010

Geo-hazard shows a rapid increasing tendency with establishment of frequent great slopes in various construction sites, especially in the unfavorable topographic condition in which about 70% of the surface is covered by the mountainous area. An repeatedly taking place on the heavy rain season is accompanied by a large scale of rockfall, and causes great damage to an individual as well as a property. Even though lots of field studies and fundamental studies have been performed to reduce this hazard, however, an essential study on the mechanism of the rockfall should be limited to the conventional studies on the slope reinforcement and/or the rockfall risk analysis. In this study, the mechanism of rockfall depending on the morphologic characteristics of slope has been simulated numerically with the PFC2D, one of the discrete element programs. For analyzing its mechanism, the input parameters relating to the slope such as surface condition, gradient, number of benches, bench gradient, and the ratio of bench width to rockfall size were taken into consideration.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.3
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• pp.83-92
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• 1999

To investigate the influence of forest road characteristics and site conditions on the stability of forest-road in granite area, four forest roads had been selected in Kyongbuk regions. The total of 13 road characteristic variables were evaluated by the discriminant analysis. The factors influencing the stability of forest road were bed rock, slope length, coverage, hardness, side-ditch erosion and road width. But aspect and soil texture were not significant for the stability in this area. In the correlation between forest environment and road structure, hardness and bed rock was highly significant in stability group, and coverage and side-ditch erosion was highly significant in instability group. 75 of 175 segments were instable whereas the others were stable. The centroids value by discriminant function in the stability and instability were estimated to 3.0585 and -1.9116, respectively. The stability criterion of forest road was discriminated from the centroids value of the each group. The main factors contributing the stability of forest road were significant in order of side-ditch erosion, coverage, soil texture, elevation, gradient, slope length and construction year. The prediction rate of discriminant function for stability evaluation of forest road was as high as 97.44%. In conclusion, the forest road structure factors such as length, coverage and slope gradient were controlled by construction techniques. If the factors like those should be considered in design, construction and forest road management, the stability of forest road may increase more. And also, it is necessary to take slope protection measures like small terraces and retaining walls for stability of cut slope.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.476-488
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• 1997

The purpose of this study was to figure out the suitable field standards for revegetation measures on cut-slopes in consideration of the environmental factors. The field survey was conducted from 1995 to 1996 on highway cut-slopes. The results obtained could be summarized as follows; The major revegetation measures surveyed were 5 major measures as a whole in descending order of seed-spraying measures, block-sod pitching measures, latticed block pitching measures, hydro-seeding measures with seed-fertilizer-soil materials, and several netting measures on highway cut-slopes. According to the analysis of the environmental factors, the plant coverage was affected several major environmental factors which were soil factors(soil hardness, soil texture, soil and rock condition), and site factors(slope gradient, slope length). From a viewpoint of optimum selection, the major 3 factors(soil factors, slope gradient factors, slope length factors) should be considered for selection of revegetation measures on highway cut-slopes.

• Journal of The Geomorphological Association of Korea
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• v.18 no.2
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• pp.65-80
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• 2011

This is to find out geomorphological environment of optimum location for the object of dwelling site of Bronze Age (hereinafter called dwelling site) of total 177 unit confirmed in Yongducheon basin and Onyangcheon basin (hereinafter called investigation-object basin) in Asan-si Chungnam. To do this, hill of investigation-object basin where dwelling sites were confirmed was divided into 11 units of hillslope geomorphological and this was combined with the grade of 5 units of gradient and again subdivided into total 55 units of micro-landforms of Hillslope. Based on this, in the viewpoint of 'gradient of each of micro-landforms' analyzed 'number of dwelling sites' and 'dwelling site distribution density (unit: number of dwelling sites/1000m2)'. As the result, the optimum geomorphological environment where dwelling sites were located was largely confirmed be 5 units(① semi-gentle slope land of crest slope ②gentle slope land of crest slope ③ slope of upper sideslope ④ flat land of crest slope ⑤ flat land of crest flat). It is thought that this analysis data will be used in the future as basic data for the study of predicting distribution of dwelling sites in Bronze Age which might have been buried in the investigation-object basin.

• Journal of Sensor Science and Technology
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• v.29 no.3
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• pp.141-148
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• 2020

To find food, homes, and mates, some animals have adapted special sensing capabilities. Rather than using a passive method, they discharge a signal and then extract the necessary information from the response. More importantly, they use the slope of the detected signal to find the destination of an object. In this paper, similar strategy is mathematically formulated. A perturbation and correlation-based gradient estimation method is developed and used as a sensing strategy. This method allows us to adaptively sense an object in a given environment effectively. The proposed strategy is based on the use of gradient values; rather than instantaneous measurements. Considering the gradient value, the sampling frequency is planned adaptively, i.e., sparse sampling is performed in slowly varying regions, while dense sampling is conducted in rapidly changing regions. Using a temperature sensor, the proposed strategy is verified and its effectiveness is demonstrated.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.4
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• pp.1-11
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• 2001

This study was carried out to analyze the characteristics of forest environmental and stream morphological factors by using the quantification theory(I) for evaluation of the watershed stability. Present annual mean sediment yield of erosion control dams were investigated in 167 sites of erosion control dam constructed during 1986 to 1999 in Gyeongbuk. The results obtained from this study were summarized as follows; According to the coefficients of partial correlation, each factor affecting to sediment was shown in order of gravel contents, number of first streams order, number of total streams, length of total streams, forest type, length of main stream, parent rock, stand age, soil texture, stream order, slope gradient, soil depth and aspect. Descriptions of class I were as follow; Igneous rock of parent rock, hardwood stands of forest type, less than 20 year of stand age, less than 30cm of soil depth, sandy clay loam of soil texture, more than 41% of gravel contents, south~east of aspect, 2,501~3,500m of length of main stream, 21~25 of number of total streams, 5,501~10,000m of length of total streams, 3 or more than 4 of stream order, more than 16 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class II were as follow; Metamorphic rock of parent rock, coniferous stands of forest type, more than 25 year of stand age, 31~40cm of soil depth, silt loam of soil texture, 11~20% of gravel contents, north~west of aspect, 2,501~3,500m of length of main stream, 16~20 of number of total streams, 3,501~5,500m of length of total streams, 3 of stream order, 11~15 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class III were as follow; Sedimentary rock of parent rock, mixed stands of forest type, more than 25 year of stand age, more than 51cm of soil depth, silty clay loam of soil texture, less than 10% of gravel contents, south~west of aspect, less than 500m of length of main stream, less than 5 of number of total streams, less than 1,000m of length of total streams, less than 1 of stream order, less than 2 of number of first stream orders and less than $25^{\circ}$ of slope gradient. The prediction method of suitable site for erosion control dam divided into class I, II, and III for the convenience of use. The score of class I evaluated as a very unstable area was more than 8.4494. A score of class II was 8.4493 to 6.0452, it was evaluated as a moderate stable area, and class III was less than 6.0541, it was evaluated as a very stable area.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.354-365
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• 1993

The purpose of this investigation is to point out the physical fixation and stability of banking slopes of forest roads by invasion of trees. We investigated the situations of sediment discharge and coverage of invaded trees at banking slopes of forest roads. The coverage of invaded trees were calculated from crown injection based on the stable slope and was compared with length of slope, slope gradient, and passage years after construction of forest road. 1. We investigated on the sediment discharge and the invasion of trees at banking slopes, which were actually observed 8 forest roads of Kyonggi-Do and Kangwon-Do. 2. There was no physical stability of the banking slope due to the surface erosion and slope failure, but the tree invasions were active at the stable plots. 3. The length of slope was constructed to 4.0m to 61.0m and recent forest road was mainly constructed to the slopes longer than 30m. There was strong regional effect between the length of slope and the coverage of invaded trees and the above two factors were inversely proportional to each other. 4. There was no significant relationship between the slope gradient and the coverage of invaded trees and the slope constructed within the angle of repose showed the relatively high coverage of invaded trees. 5. There was no significant relationship between the passage years and the coverage of invaded trees in the same investigative region after the construction of forest road. But there was a gradually increasing relationship of tree invasion between above two factors. However, there was some limitation to expect the invasion of the tree species. 6. In the light of the above results, we suggest that the construction of forest road may need foundation work and vegetation work simultaneously for the physical stability to make the environment of tree plantation and that the reasonable increase of construction cost of forest road may be prior to the other factors.

• Journal of Korea Water Resources Association
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• v.33 no.S1
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• pp.28-36
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• 2000

A TIN, Triagulated Irregular Network, based topographic modeling method and a distributed rainfall-runoff model using the topographic representation is presented. In the TIN based topographic representation, a watershed basin is modeled as a set of contiguous non-overlapping triagular facets : the watershed basin is subdivided according to streamlines to deal with water movement one-dimensionally ; and each partitioned catchment is approximated to a slope element having a quasi-three-dimensional shape by using cubic spline functions. On an approximated slope element, water movement is represented by combined surface-subsurface kinematic wave equations considering a change of slope gradient and slope width. By using the distributed rainfall-runoff model, the effects of spatial variability of soil properties on runoff response are examined.

• Proceedings of the Korea Water Resources Association Conference
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• 2000.05a
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• pp.28-36
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• 2000

A TIN, Triangulated Irregular Network, based topographic modeling method and a distributed rainfall-runoff model using the topographic representation is presented. In the TIN based topographic representation, a watershed basin is modeled as a set of contiguous non-overlapping triangular facets: the watershed basin is subdivided according to streamlines to deal with water movement one-dimensionally; and each partitioned catchment is approximated to a slope element having a quasi-three-dimensional shape by using cubic spline functions. On an approximated slope element, water movement is represented by combined surface-subsurface kinematic wave equations considering a change of slope gradient and slope width. By using the distributed rainfall-runoff model, the effects of spatial variability of soil properties on runoff response are examined.