• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.493-502
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• 2006

This study analyzed greenspace structure focused on greenspace areas and vegetation structure for Yanggu, investigated resident attitudes to the greenspace, and explored strategies to improve greenspace functions in a rural region. Woody plant cover was approximately 29% for parks and only 3% for commercial gardens. The amount of planting for Yanggu was poor, as compared with the results of similar studies for urban areas. Trees, of which dbh was below 20cm, accounted for 91% of all trees and the tree-age structure was largely characterized by a young, growing tree population. Based on the analysis of mean importance values (MIV) of woody plant species, only a few were different in dominant species from urban areas. Four species among 10 species with highest MIV in Yanggu were very common species also ranked among 10 in cities. The most dominant species planted in residential and commercial gardens were practical plants such as fruit or edibles. Greenspace covered about 69% of parks, 39% of residential gardens, 37% of institutional gardens, 24% of streets, and 15% of commercial gardens, respectively. Tree planting potential revealed that present woody plant cover can be increased additionally by 6 times in the streets and by 2 times in the residential and commercial gardens. Based on the results of greenspace structure, planting patterns, and questionary investigation, some strategies were suggested to enlarge greenspace including its environmental functions. They included identifying each street section through setting up themes and planting appropriate species, creating multilayered vegetation structures, and promoting planting in bare grounds of gardens and around a buildings for saving energy.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.1-11
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• 2023

This study intended to develop a technique for quantitatively and 3-dimensionally predicting the potential failure zone and impulse that may occur when trees are fall down. The main outcomes of this study are as follows. First, this study established the potential failure zone and impulse calculation formula in order to quantitatively calculate the risks generated when trees are fallen down. When estimating the potential failure zone, the calculation was performed by magnifying the height of trees by 1.5 times, reflecting the likelihood of trees falling down and slipping. With regard to the slope of a tree, the range of 360° centered on the root collar was set in the case of trees that grow upright and the range of 180° from the inclined direction was set in the case of trees that grow inclined. The angular momentum was calculated by reflecting the rotational motion from the root collar when the trees fell down, and the impulse was calculated by converting it into the linear momentum. Second, the program to calculate a potential failure zone and impulse was developed using Rhino3D and Grasshopper. This study created the 3-dimensional models of the shapes for topography, buildings, and trees using the Rhino3D, thereby connecting them to Grasshopper to construct the spatial information. The algorithm was programmed using the calculation formula in the stage of risk calculation. This calculation considered the information on the trees' growth such as the height, inclination, and weight of trees and the surrounding environment including adjacent trees, damage targets, and analysis ranges. In the stage of risk inquiry, the calculation results were visualized into a three-dimensional model by summarizing them. For instance, the risk degrees were classified into various colors to efficiently determine the dangerous trees and dangerous areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.966-970
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• 2007

하천정비기본계획에는 하천 등급별로 빈도 홍수량과 빈도 홍수위가 제시되어 있다. 홍수위 산정에는 조도계수가 영향을 미치므로 모든 하천정비기본계획에는 하천 구간별 조도계수가 산정, 제시되어 있다. 그런데 하천의 이용은 시대에 따라 변화되고 있으며 최근 환경적 기능이 강조되고 있어 하천 내의 수목에 대한 관점 또한 과거 치수 목적이 위주가 되었던 시대와는 달라졌다. 그러므로 이제는 홍수터를 포함하는 하천 부지내에서 자생 혹은 식재한 수목에 대한 고려가 필요한 상황이다. 수목 생장은 조도계수를 변화시키므로 이를 고려하기 위해서는 다시 조도에 대한 고려한 필요한 상황이다. 이러한 배경에서 본 조사는 국내의 다양한 하천에 대해 기존에 수립된 하천정비기본계획을 토대로 조도계수의 범위와 특성 및 그 산정 방법을 분석하는데 목적을 두었다. 하천정비기본계획 분석 결과, 조도계수는 하천 규모와 관계없이 주로 $0.025{\sim}0.040$ 범위에 있으며, 대체로 과업 구간이 5개의 이하로 분할되어 적용되었다. 산정 방법은 주로 하상재료 및 하도 형태에 대한 현장 판단과 기수립된 하천정비기본계획의 참고, 과거 흔적수위를 기초로 부등류 모형을 적용하는 등이었다. 본 조사의 결과로 현재 조도계수 산정의 문제점이 분석되었으며 향후 조도계수 산정의 개선 방향이 제시되었다.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.535-544
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• 2009

This study was conducted to establish the selection criteria for the trees to be transplanted in the forest reserves which are expected to be developed in the future. The main task in this endeavor was to access the transplantability of the trees focused on their feature, diameter at breast height (D.B.H.), soil feature, etc. The selection of the trees for transplantation consisted of two stages. The first stage was to select trees on the basis of their indigenousness and forest successional stage. The second was to select trees on the basis of their type, D.B.H., the layers of soil, etc. At the first stage, the trees which are not indigenous or expected not to survive were eliminated from the selection list, and the result showed that approximately 5.9% (about 3,841 trees) of the trees proved to be inadequate for transplanting. At the second stage, the investigation of the trees based on the criteria of tree type, D.B.H., the layers of soil was carried out, and the result showed that approximately 33.7% (1,218) out of 3,613 trees turned out to adequate for transplanting however, 23.0% of the trees, which are 829 trees, were found to be impossible to transplant. In addition, it was discovered that in the case of approximately 43.3%(1,566 trees) of the trees there was little difference between transplanting cost and planting cost of new trees. Therefore the investigation indicated that it is more advisable to transplant trees to preserve the ecological environment. However, the study showed that there are other elements to be considered, such as tree feature and soil condition, for the successful tree transplantation, and the necessary information can be provided by the managing personnel who are in charge of the forest.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.4
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• pp.77-84
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• 2013

With the increase in occurrence frequency and severity of natural disasters due to climate changes arising from global warming, damage in the landscaping field is rising. This leads to legal disputes, and is increasing social and economic damage, too. Especially even though landscape trees which are highly affected by external environments, suffer lots of damage from natural disasters, there is no specific scope of disaster criteria and thus it brings plenty of problems of damage restoration and compensation. Therefore, this study aims to suggest that gives ways to improve related criteria for damage of landscape trees from natural disasters. For this objective, this study analyzed damage cases of landscape trees and precedents, and compared Korean and Japanese legal systems and criteria regarding natural disasters with each other. The analysis result showed that opinions of experts have a great deal of influence on judgment results, since there is no definite legal basis on damage from natural disasters in the landscaping field. This implies the need for a professional and objective appraisal process. According to the comparative analysis of Korean and Japanese legal systems and criteria regarding natural disasters, Korea lacked in laws and criteria on natural disasters of landscape plants in Korea, whereas there were concrete disaster assessment standards of landscape trees in Japan. For improving natural disaster-related systems and criteria in the landscaping field, therefore, this study presented 'Revision of related laws', 'Revision of appraisal and loss assessment criteria', 'Revision of standard specification of landscaping project', 'Compulsory insuring against disasters', 'Reasonable fulfillment of contract', and 'Compulsory cost estimation for disaster restoration', as improvement plans.

• Korean Journal of Plant Resources
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• v.34 no.2
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• pp.144-155
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• 2021

This study was conducted to analyze community structure and species composition of Abies koreana forest. Field survey was carried out from June, 2019 to 2020, September. 121 plots (20×20 m) were set up, 5 herb layer plots (3×3 m) were constructed for each plot, and there, Diameter at Breast Height(DBH), height, environmental factor were measured. It was analyzed that water stress did not have a significant effect on the factors affecting the growth of A. koreana in Mt. Halla-san, and in the case of Mt. Deokyu-san, the more forest stands located at the ridge, the higher the tree density. It was found that the factors affecting the distribution of Abies koreana were not consistent according to the environment of study site.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.4
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• pp.441-448
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• 2010

This paper estimates the tree height using Airborne LiDAR that is obtained for each season to analyze its influence based on a canopyclosure and data fusion. The tree height was estimated by extracting the First Return (RF) from the tree and the Last Return (LR) from the surface of earth to assume each tree via image segmentation and to obtain the height of each tree. Each data on tree height that is collected from seasonal data and the result of tree height acquired from the data fusion were compared. A tree height measuring device was used to measure on site and its accuracy was compared. Also, its applicability on the result of fused data that is obtained through the Airborne LiDAR is examined. As a result of the experiment, the result of image segmentation for an individual tree was closer to the result of site study for 1 meter interval when compared to the 0.5 meter interval of point cloud. In case of the tree height, the application of fused data enables a closer site measurement result than the application of data for each season.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.22-30
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• 2019

The demand for National Woodland Burial Grounds is expected to increase as interest in natural burial, including woodland burial, is increasing. This study was performed to provide evaluation criteria applying weighting factors to the evaluation for location selection. Through literature review, location selection evaluation factors for forest facilities, similar to forest welfare facilities, were reviewed and analyzed. As a result of the analysis, 74 preliminary evaluation criteria were selected. Based on the results, three expert groups (public servants in central and local governments and other public agencies in charge of forest welfare facility, related field researchers, and civil experts) reviewed the preliminary evaluation factors. Evaluation factors were classified into two categories, 6 sub-categories, and 22 segments. The selected evaluation factors were layered for the second preference survey. They were classified into Forest Environment and Human Environment, and those categories were further classified into three categories. Then they were further classified into segments. After segmentation, the experts who participated in the first survey checked the differences in the significance of the layered factors by utilizing AHP. The site evaluation criteria table was prepared using the evaluation criteria and the significance of each layer. In order to apply it to the candidate sites, 10 sites including the existing National Woodland Burial Grounds and 9 candidate sites considered in the previous studies were compared and analyzed including Ulju County Ulsan City, Suncheon City Jeollanam-do and Janggun-myeon Sejeong City.

• Nuclear Engineering and Technology
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• v.19 no.4
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• pp.279-291
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• 1987

The event tree/fault tree techniques used in the current probabilistic risk assessment (PRA) of nuclear power plants are based on the binary and static description of the components and the system. While these techniques Bay be adequate in most of the safety studies, more advanced techniques, e.g., the Markov reliability analysis, are required to accurately study such problems as the plant availability assessments and technical specifications evaluations that are becoming increasingly important. This paper describes a Markov model for the Reactor Protection System of a pressurized water reactor and presents results of model evaluations for two testing policies in technical specifications.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.302-306
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• 2016

There are various methods to evaluate tree vigor. Cambial electrical resistance represents tree vigor using the method of electrophysiological diagnosis. This study investigated the vigor of several tree species using Shigometer, and compared the differences among the species. The factors, such as foliation, trunk orientation and bark temperature, which affect electrical resistance were also investigated. The needle penetration into cambium was controlled to keep the depth consistent in order to minimize measurement error. Each of three trees were selected from Zelkova serrata, Ginkgo biloba, Metasequoia glyptostroboides, Pinus koraiensis, and Liriodendron tulipifera. The electrical resistances were measured at 60 and 120 cm height of the stem in 4 directions from March until May 2011. The soil conditions in surrounding areas and tree stress responses were also measured. The results were analyzed for the relationship between electrical resistance and the affecting factors. The electrical resistance showed a relatively higher level before foliation until mid-March. The values started to decline from April and recorded a minimal level on May 11. The changes of soil moisture, soil electric conductivity, and tree stress responses during the measurement period showed a similar trend to that of electrical resistance. The Pinus koraiensis, an evergreen conifer, showed few changes on the electrical resistance values during the measurement period. Zelkova serrata, Ginkgo biloba, and Metasequoia glyptostroboides showed the highest bark temperatures and lowest electrical resistances at their south-facing stem. Shigometer can provide measures simple to assess tree vigor in the fields, and to the management of trees.