• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.59-66
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• 2019

This study was conducted to evaluate the effect of the synthetic forest road network by calculating the optimal road density and layout of the forest road network in order to construct the systematic road network in the forested area. For this, five comparative routes were additionally planed and compared through evaluation indicators. As a result, the optimum road density of the study site was estimated to be 18.4 m/ha, and the synthetic forest road network was the best in the four indicators such as average skidding distance, standard deviation of skidding distance, development index, and circuity factor. In addition, the synthetic forest road network was comparable to the main road network by about 4 %p in the timber volume available and potential area size for logging, but the construction cost of the road was about 20 %p lower. It showed a synthetic forest road network was better in terms of economy.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.161-178
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• 2017

Whereas the demand for development of forested areas covering more than 60% of Korean territory, permission on the forest development has been still given from the perspective of effective land utilization rather than conservation. As the assessment of large forested areas usually focuses more on forest structure, it has its limitation of observing and analyzing the interior change in forest in this way. This study was aimed at computing landscape metrics using a presence vegetation map and FRAGTSTATS 4.2 and analyzing vegetation mosaics. Colonies in native vegetation were classified into a series of major groups and sub-groups based on the native species within the colonies. The colonies were investigated by analyzing a suite of landscape metrics - Core Area, Percentage of Landscape, Number of Patches, Patch Density, Largest Patch Index, Total Edge, Edge Density, Landscape Shape Index, Mean Patch Area, Euclidean Nearest Neighbor. In the Chungnam province major groups and sub-groups of colonies classified based on the proportion of pine and oak species, and pine species was the principal one in terms of distribution area. As for the competition between pines and oaks, while the coverage of pine-centered colonies were three times larger than those of oak-centered ones, pine colonies showed the greater number of patches and therefore higher fragmentation than oaks at the major group level. For the sub-groups, the largest coverage colonies were not only indicated by Pinus densiflora-Quesrcus mongolica colonies among P. densiflora-centered colonies, Q. accutissima colonies among Q. accutissima-centered ones, Q. accutissima-P. densiflora colonies among Q. accutissima-centered ones, Q. mongolica colonies among Q. mongolica-centered ones, P. thumbergii colonies among P. thumbergii-centered ones, and Q. serrata-Q. acutissima colonies among Q. serrata-centered ones, but also revealed more severely mosaicked than other smaller colonies. The overall mosaicking degree estimated by landscape metrics was considered useful for monitoring and investigating vegetation. However, in order to develop management strategy based on analyzing the reason for the mosaicking process and anticipating a trend in vegetation succession, it is essential to further study about ecological characteristics of each colony in the vegetation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.4
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• pp.57-67
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• 2014

The vigor condition of trees is an important indicator for the management of urban forested area. But difficulties in how to assess the tree vigor condition still remain. Previous efforts were limited in the 1) measurement of single indicator rather than using multiple indices, 2) purpose-oriented measurement such as for air-pollution effect or specific pathological symptom, and 3) ordinal-scale evaluations by field crews 4) despite human errors based on his/her experiences or prior knowledge. Therefore, this study attempted to develop a quantitative and objective methodology for assessing tree vigor condition, by measuring multiple modules and building the profile inventory. Furthermore, the possibility and limitations were discussed in terms of schematic frames describing tree vigor condition. The vigor condition of 56 flowering cherry plants in urban park were assessed by in-situ measurements of following eight items; growth of crown(Gc), growth of shoots, individual tree volume(Vol), plant area index, woody area index, leaf area index, leaf chlorophyll content(Lc) and leaf water content(Lw). For validation, these measurements were compared with the ranks of holistic tree vigor condition, which were visually assessed using a 4-point grading scale based on the expert's knowledge. As a result, the measures of each evaluation item successfully highlighted a variety of aspects in tree vigor condition, including the states of both photosynthetic and non-photosynthetic parts. The variation in the results depending on evaluated parts was shown within an individual tree, even though the broad agreement among the results was found. The result of correlation analysis between the tested measurements and 4-point visual assessment, demonstrated that the state of water-stressed foliage of the season (Lw) or the development of plant materials since sapling phase (Vol) could be better viewed from the outer appearance of trees than other symptoms. But only based on the visual assessment, it may be difficult to detect the quality of photosynthesis (Lc) or the recent trend in growth of trees (Gc). To make this methodology simplified for the broad-scale application, the tested eight measurements could be integrated into two components by principal component analysis, which was labelled with 'the amount of plant materials' and 'vigor trend', respectively. In addition, the use of these quantitative and multi-scale indicators underlies the importance of assessing various aspects of tree vigor condition, taking into account the response(s) on different time and spatial scale of pressure(s) shown in each evaluated module. Future study should be advanced for various species at diverse developing stages and environment, and the application to wide areas at a periodic manner.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.528-536
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• 2014

The aim of this study was to investigate the damage characteristics induced by winter freezing of evergreen broad-leaved trees distributed in urban area of warm temperate forest zone, which are gaining increased interest recently as climate change. The results of the study indicated that, as for 'stem injury', Camellia japonica Linne (59.6%) had the weakest damage, while Ternstroemia gymnanthera Sprague (83.3%) had the most severe damage. By the visual evaluation of freezing injury according to the characteristics of plantations environment, the observations of single planting (p<0.01) in planting method had weaker damage than those of group planting, the observations of under tree (p<0.001), plain (p<0.001), and organic matter plenty (p<0.05) in plantations characteristics had significant differences with relatively weaker damage than the observations of open space, slop, and scarcity, respectively. Tree height (-0.432) and crown width (-0.470) among growth factors were negatively correlated with the severity of damage, respectively. Therefore, the selection of tree species is vital for the successful creation of these urban forested area by making considerations of planting environment, and further research on evergreen broad-leaved trees is needed in this aspect.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.109-120
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• 2016

This study aims to assess vulnerability in urban thermal environments of Seoul by using indicators frequently used in previous studies as well as effective indicators for spatial planning like urban and environmental planning. For this purpose, fifteen indicators that influence urban thermal environments such as heat waves, urban heat island effects, and urban micro-climates were identified based on literature reviews. Indicators for presenting urban structure and spatial properties were included; for example, building volume as 'exposure to climate', buildings completed before 1980 as 'sensitivity', and green space areas as 'adaptive capacity'. Among them, twelve indicators were applied to assess vulnerability in urban thermal environments of Seoul by using a GIS spatial analysis combined with fuzzy logic. The results show that the Gangnam area is identified as more vulnerable to a heat environment as compared to the Gangbuk area. In the Gangnam area, Seocho-gu, Gangnam-gu, Dongjak-gu, Yeongdeungpo-gu, Gangseo-gu were relatively high in vulnerability, while Dongdaemun-gu, Gangbuk-gu, Gwangjin-gu, Jungrang-gu were relatively high in the Gangbuk area. Gwanak-gu, Dobong-gu, Eunpyeong-gu, and Nowon-gu, which include forested areas, have low vulnerability in the sectors of 'exposure to climate' and 'sensitivity' due to the impact of Gwanaksan and Bukhansan. However, some areas with high vulnerability like Seocho-gu and Gangnam-gu may have lower vulnerability if the indicator 'status of air conditioning' from the sector of 'adaptive capacity' is used. This study could support the establishment of a practicable thermal environment policy and spatial planning to reduce heat-related risks in the field of urban and environmental planning.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.441-448
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• 2008

The purpose of this study was to analyze chemical water quality, fish trophic guilds, tolerance indicators, and fish community conditions in the Gap Stream and to compare the stream conditions between the unimpacted site and impacted site. This study was conducted in the physically stable season (May 2008) to minimize physical impacts such as flow and hydrological disturbance, and applied the study in the Gap Stream with two sites of unimpacted upstream site (Unim-S), mainly surrounded by forested area and impacted site (Im-S), influenced by the wastewater disposal plants and industrial complex in the urban region. Chemical data analysis showed that the degree of organic matter pollution, based on BOD, and COD, was $2{\sim}3$ fold greater in the Im-S than the Unim-S, and that TP, as eutrophication indicators, was 4.7 fold greater in the Im-S. Also, $NH_3-N$ was in 8.2 fold greater in the Im-S ($6.25\;mg\;L^{-1}$) than the Unim-S ($0.76\;mg\;L^{-1}$), indicating a massive influence of wastewater from the disposal plant. Similar results were found in other chemical parameters. Thus, chemical impacts in the Im-S were evident, compared to the unimpacted site. Evaluations of tolerant indicator species indicated that sensitive species were dominant in the Unim-S (23.9%) and tolerant species were dominant (97.8%) in the Im-S. Condition factor (CF) was averaged 0.95 ($0.68{\sim}1.18$) in the Unim-S and 1.08 ($0.93{\sim}1.22$) in the Im-S. Fish community in the Unim-S and Im-S was categorized as Zacco-community and Hemibarbus-community, respectively, and the community diversity index (H') was significantly (p<0.05) higher in the Unim-S (0.810) than the Im-S (0.466). Overall, our results suggest that the comparison approach of various chemical and ecological indicators provide important information in identifying multiple stressors in the stream ecosystems.

• Journal of Korean Society of Rural Planning
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• v.22 no.3
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• pp.21-31
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• 2016

This is a comparative study focused on the scenic landscape preferences derived from visitors's perceptions at the Dulle-gil and the uphill trail in Bukhansan National Park. Unlike previous landscape assessment methods, this study contains more direct and on-site analysis with methods of understanding the visitors' perceptions by using 'visitor employed photography(VEP)' which requires each visitor to take preferable scenic landscape with one's own smart phone camera. The scenic landscape types at two different trails were categorized and then the types favoring most of participants were verified. There are total number of 16 visual landscape types preferred by participants at both the Dulle-gil and the uphill trail in Bukhansan National Park. As in terms of consensus photography(CP) on the Dulle-gil was found to have more diverse elements including both natural and artificial elements compare to the uphill trail. Furthermore, the perceptually excited node(PEN) at the Dulle-gill were found to be more scattered evenly whereas PEN at the uphill trail were concentrated on the entrance and the top of the mountain. It is necessary to consider that the scenic landscape management at the Dulle-gil and the uphill trail require different approaches. Facilities were set based on careful consideration of distinctive geographical features and vegetation in the Dulle-gil. And the management need to be focus on the 'forested area' maintaining natural state in the uphill trail. Futhermore, the result of the CP and PEN in the trails would be helpful to proceed the next step of landscape perception study depending on characteristics of groups.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.77-87
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• 2012

Discussion on North Korea as UN-REDD (Reduced Emissions from Deforestation and Degradation in developing countries) project target continues with a view to preventing deforestation and to securing CER(certified emission reduction) for South Korea. However, due to North Korea's political shutdown, it is hard to acquire information required for the REDD project registration. This research intends to acquire objective data using satellite images in the Mt. Geumgang. More than 20% of entire forested area were disappeared during the past two decades mainly due to conversion into agricultural farming land. Further, it is expected that persistent deforestation will go on. The reduction potential of the carbon emission is estimated as approximately 617,000 tCO2/year~663.000 tCO2/year. Thus, Mt. Geumgang is considered as realistic REDD target, which is attractive to South Korea, given that the obligation to reduce greenhouse gas emission is likely to be imposed upon the country. Further, political and social benefits due to reduced military conflict make Mt. Geumgang as UN-REDD project target invaluable.

• Journal of Korea Water Resources Association
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• v.34 no.2
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• pp.131-140
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• 2001

The present study is focused on improving the methodology for the determination of parameters involved in USLE(Universal Soil Loss Equation) based on distributed system concept and investigation of sediment delivery ratio. Generally the distributed system concept consists of grid networks throughout the watershed and sediment can be traced from grid to rid in the direction of the steepest descent. The sediment yield data together with physical data of 10 small irrigation reservoirs in Kyounggi-Do are collected. After the sediment delivery ratio of a grid is defined to be related tothe fraction of forested or covered with delivery proofing area of the grid, the preportionality coefficient(C$_1$) is introduced. The distributed system model is calibrated using the available data for 8 reservoirs and is verified with the data for the ramaining 2 reservoirs, and regression analysis is made to express the proportionality coefficient $C_1$ in terms of watershed physical characteristics. By applying this results the verification of the distributed system model for 2 reservoirs showed a fair result, which justifies the applicability of the proposed method in the present study.

• Korean Journal of Remote Sensing
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• v.8 no.2
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• pp.79-91
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• 1992

With recent development in spaceborne imaging radar system, there are growing interests using satellite synthetic aperture radar(SAR) data in various applications. This study attempted to identify the relationships between several forest stand characteristics and radar backscatter, measured from space altitude altitude at three incidence angles. Shuttle Imaging Radar-B(SIR-B) data were collected over a forested area in northern Florida in October, 1984. By using various sources of reference data (forest type maps, inventory records, aerial photographs, and Landsat Thematic Mapper data), about 400 forest stands of known characteristics were carefully located in the radar data. Relative radar backscatter for the three incidence angles of SIR-B data were compared with known forest stand parameters such as mean tree height, diameter at breast height(DBH), stand density, biomass, and relative amount of understory vegetation. The results show that these stand parameters have statistically significant correlations with the radar backscatter. In addition, the SIR-B radar backscatter from a certain stand parameter turned out differently at the three different incidence angles. Finally, the types and characteristics of currently available satellite SAR data are discussed.