• Journal of Environmental Impact Assessment
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• v.8 no.3
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• pp.77-90
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• 1999

The degree of green naturality (DGN) has played a key role for maintaining the environmental quality from inappropriate developments, although the quality and effectiveness of the mapping of DGN has been under debate. In this study, spatial distribution of degree of green naturality was initially estimated from forest stand maps that were produced from the aerial photo interpretation and extensive field survey. Once the boundary of initial classes of DGN were defined, it were overlaid with normalized difference vegetation index (NDVI) data that were derived from the recently obtained Landsat Thematic Mapper data. NDVI was calculated for each pixel from the radiometrically corrected satellite image. There were no significant differences in mean values of vegetation index among the initial DGN classes. However, the satellite derived vegetation index was very effective to delineate the developed and damaged forest lands and to adjust the initial value of DGN according to the distribution of NDVI within each class.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.181-188
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• 1997

Vegetation is an important factor in EIA(Environmental Impact Assessment) and it is assessed according to DGN(Degree of Green Naturality) in EIS(Environmental Impact Statement) preparation. But DGN has room for improvement of assessing vegetation Status. This study introduced NDVI(Normalized Difference Vegetation Index) for improving status assessment method that subjects to DGN. For the application of NDVI, Landsat TM data of Chunchon on May 2, 1989 and June 1, 1994, and data of Ulsan on November 5, 1984, November 2, 1992 and May 9, 1994 were used. It compared NDVI with DGN according to season and location. The correlation coefficient value for the spring image (1994, 0.7, p=0.01) was proved to be higher than that of autumn (1984, 0.5, p=0.01).

• Journal of Korean Society of Forest Science
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• v.64 no.1
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• pp.64-73
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• 1984

As data basic to policy in nature conservation, the Degree of Green Naturality (DGN) survey was usually carried out. This also explains the impact of human interference to natural environment. Gongju gun and Yeongi gun were surveyed in the summer of 1983 to determine the DGN of these districts. Then, the surveyed DGN was compared to the existing standard. The results obtained appeared that the average DGN of these districts ranged about 5.1 to 5.9 and especially the ratio of DGN 7-graded area was high. Because of difficulties in applying the existing standard directly to middle part of Korea, further improvement on the existing standard for ranking or surveying the DGN should be reconsidered.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.47-54
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• 1997

Vegetation Index(VI) derived from remote sensing data is used to assess ecosystem factor in Environmental Impact Assessment(EIA) process. Ecosystem factor has been prepared by Degree of Green Naturality(DGN) mainly in Environmental Impact Statements. But DGN has room for improvement of assessing actual ecosystem situation. The objectives of this study are to define the relationship between field measure DGN and VI, and to develop methodologies to use VI for assessing the status and conditions of natural ecosystem. For verification of DGN and VI, 35 sites using global positioning system are selected and reviewed. Correlation coefficients of DGN and VI shows highly as 0.69. Also VI in EIA found it can be applied to assess ecosystem. It concluded that VI as well as DGN can be applied to assess ecosystem newly and largescale.

• Journal of Environmental Impact Assessment
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• v.11 no.3
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• pp.129-143
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• 2002

This study was executed environmental assessment to determine whether or not the national landuse planning change on the reserved area for a rope way in the ice valley(Eoreurngol) of Miryang. The selected survery area is $1,633,442m^2$ and assessed with flora, actual vegetation, degree of green naturality(DGN), sere stage and wild birds. The flora was summarized as 132 taxa which is 90 genera, 117 species, 12 varieties and 3 forms. The actual vegetation was classified 24 types and nature forests like Quercus and deciduous-broad leaf community was distrubuted broadly. Especially Quercus and deciduous-broadleaf communities were assessed high rarity value in Miryang. From the analysis of DGN, it were found out that DGN 8 is 72.5% and DGN 9 is 3.9%. At the analysis of sere stage, the communities were divided 4 with Quercus mongolica, Pinus densiflora, Carpinus laxiflora and deciduous-broadleaf community. Wildbirds was observated as 30 species and 161 ea and Aix galericulata (natural monument no. 327) especially inhabited there. From the above nature ecosystem assessment, the survey area has high quality naturalness, so it was turned out that a rope way construction might be not suitable in survery area.

• Korean Journal of Environment and Ecology
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• v.18 no.2
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• pp.167-174
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• 2004

This study was carried out to investigate the actual vegetation and the DGN(Degree of Green Naturality) from Namdeogyusan of the Deogyusan National Park to Sosagogae in the Baekdudaegan in 2003. The actual vegetation of the surveyed site were classified into 14 plant communities and cropland, etc.; Natural forest were classified into 9 plant communities; Quercus mongolica communities, mixed forest, deciduous broadleaf plant communities, Pinus densiflora communities, etc. And afforested lands were classified into 4 forest types; Larix leptolepis communities, Pinus rigida communities, etc. The DGN 9 was appeared the widest area as 57.97% and the DGN 8 was 26.80%. The DGN 1 and 2 were appeared as 5.18% at Sosagogae and Paejae district in outside of the Deogyusan National Park.

• Korean Journal of Environment and Ecology
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• v.17 no.2
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• pp.153-168
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• 2003

Wangpicheon, which is located in Uljin-Gun, Korea, is threatened with various developments plan recently. To investigate the forest structure, actual vegetation and degree of green naturality(DGN) in Wangpicheon, survey was carried out within about 1km width from the stream. In the analysis of actual vegetation, the forest type around Wangpicheon is differentiated into 26 vegetation ones. In these, six Pinus densiflora - dominated vegetation types are appeared a great many of them. In DGN analysis, 70.8% of total area is covered by DGN 8 and 0.3% of total area is covered by DGN 9. According to the analysis of classification by TWINSPAN, the community was divided by three types of Pinus densiflora community and two types of Quercus spp. community i.e. Quercus mongolica and Q. vuliabitis community. The structure of communities were analyzed using importance percentage, and species and individuals, DBH distribution and similarity analysis were executed.

• Journal of Environmental Impact Assessment
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• v.15 no.5
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• pp.339-355
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• 2006

In this paper, we reviewed the assessment criteria and conservation value used to evaluate vegetation. The Degree of Green Naturality (DGN) and the Grade of Vegetation Conservation (GVC) are both sets of criteria that estimate the degree of human disturbance or natural value of vegetation. The criteria are extensively used in decision-making about the natural environment conservation and environment impact assessment. Sometimes, social issues can rise because the criteria are not clear. This study aims to evaluate the criteria based on the many aspects of the related literatures and suggest reasonable revised criteria. In addition, criteria for representing the relative value of valuable vegetation conservation are suggested. The DGN and GVC are essentially same; both have 11 degrees and 5 grades. While the DGN is subdivided into levels of anthropogenic disturbances, the GVC indicates the priority for conserving valuable vegetation. Therefore, the DGN is very useful for assessing land development projects, etc., while the GVC is needed to delineate the Ecological Assessment Map(EAM). In conclusion, it is desirable that both criteria should be used together appropriately.

• Korean Journal of Environment and Ecology
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• v.25 no.2
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• pp.166-174
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• 2011

This study was carried out to investigate the actual vegetation and Degree of Green Naturality(DGN) in Naejangsan National Park in 2010. The actual vegetation of the surveyed site were classified into twelve plant communities and the others. Secondary forest were classified into eight plant communities; Pinus densiflora community, Deciduous broadleaf forest, Quercus mongolica community, etc. Afforested lands were classified into four forest types: P. rigida -P. densiflora forest, P. rigida forest, etc. The area of DGN 8 consisted of 60.58% while the area of DGN 9 consisted of 3.62% when compared with land area in Naejangsan National Park. The exotic plants needs to be managed for recovery of natural landscape and biological diversity in Naejangsan National Park.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.2
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• pp.31-40
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• 2012

The Environmental Conservation Value Assessment Map (ECVAM) is a five grade assessment map created with nationally integrated environmental information and environmental values. The map is made through the evaluation of 65 items, including greenbelt area and naturalness. Naturalness means original state of nature, and it is one of the most important evaluation items for conserving nature. The criteria of naturalness includes the Degree of Green Naturality (DGN) made by MOE. Using the data which has been not updated is a problem of accuracy for ECVAM. Therefore, this study would like to improve the criteria of naturalness. To improve the criteria, the study examined the effectiveness of DGN using field survey. The results of analysis the naturalness without DGN, some area changed grade of naturalness have been already damaged or cleared for agriculture and industrial purposes. The grade of naturalness should be included the concept of vegetation transition like DGN. The study suggested a improved method using vegetation type (natural and planted forest), forest age, and the grade of vegetation conservation. The method was reviewed by experts and field survey. After applying the method in South Korea, the grade of naturalness were distributed evenly like GradeI is 38.87%, GradeII is 37.62%, GradeIII is 23.51%, respectively. From the results of field survey, over 4 grade of forest age in natural forest showed similar pattern of structure and composition in original forests. Therefore, the improved criteria explained the naturalness better than existing criteria, and the accuracy of ECVAM has been improved more.