• Title/Summary/Keyword: Korean rural landscape

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Comparison of Two Methodsto Estimate Urban Sensible Heat Flux by Using Satellite Images (위성 영상을 활용한 두 가지 현열 플럭스 추정 방법 간의 비교)

  • Kim, Sang-Hyuck;Lee, Dong-Kun
    • Journal of Environmental Impact Assessment
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    • v.31 no.1
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    • pp.63-74
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    • 2022
  • In orderto understand the urban thermal conditions, many studies have been conducted to estimate the thermal fluxes. Currently sensible heat fluxes are estimated through various methods, but studies about comparing the differences between each method are very insufficient. Therefore, this study try to estimate the sensible heat flux of the same area by two representative estimation methods and compare their results to confirm the significance and limitation between methods. As a result of the study, the heat balance methods has a great advantage in terms of resolution but it can not consider the anthropogenic heat flux, so sensible heat flux can be underestimated in urban areas. When estimating based on physical equation, anthropogenic heat flux can be considered and the error is relatively small, it has a limitations in time and space resolutons. The two methods showed the largest difference in industiral areas where anthropogenic heat fluxes are high, with an average of 135 W/m2 and a maximum of 400 W/m2. On the other hand, the green and water have a very small difference with and average of 20 W/m2. The results between two methods show significant differences in urban areas, it is necessary to select a suitable method for each research purpose.

Mapping Mammalian Species Richness Using a Machine Learning Algorithm (머신러닝 알고리즘을 이용한 포유류 종 풍부도 매핑 구축 연구)

  • Zhiying Jin;Dongkun Lee;Eunsub Kim;Jiyoung Choi;Yoonho Jeon
    • Journal of Environmental Impact Assessment
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    • v.33 no.2
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    • pp.53-63
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    • 2024
  • Biodiversity holds significant importance within the framework of environmental impact assessment, being utilized in site selection for development, understanding the surrounding environment, and assessing the impact on species due to disturbances. The field of environmental impact assessment has seen substantial research exploring new technologies and models to evaluate and predict biodiversity more accurately. While current assessments rely on data from fieldwork and literature surveys to gauge species richness indices, limitations in spatial and temporal coverage underscore the need for high-resolution biodiversity assessments through species richness mapping. In this study, leveraging data from the 4th National Ecosystem Survey and environmental variables, we developed a species distribution model using Random Forest. This model yielded mapping results of 24 mammalian species' distribution, utilizing the species richness index to generate a 100-meter resolution map of species richness. The research findings exhibited a notably high predictive accuracy, with the species distribution model demonstrating an average AUC value of 0.82. In addition, the comparison with National Ecosystem Survey data reveals that the species richness distribution in the high-resolution species richness mapping results conforms to a normal distribution. Hence, it stands as highly reliable foundational data for environmental impact assessment. Such research and analytical outcomes could serve as pivotal new reference materials for future urban development projects, offering insights for biodiversity assessment and habitat preservation endeavors.

Analyzing Change of Discomfort Index for Transpiration of Street Tree (도시 가로수의 증산 작용으로 인한 불쾌지수 변화 분석)

  • Yun, Seok-Hwan;Lee, Dong-Kun;Park, Chae-Yeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.5
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    • pp.29-43
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    • 2020
  • Thermal environment of city is getting worse due to severe urban heat island caused by climate change and urbanization. The cooling effect of street tree is regarded as a effective way to ameliorate the urban heat environment. The effect is largely made up of shadow formation and transpiration. This study aims to identify how the transpiration affects the discomfort index by analyzing comprehensive impact of the transpiration on the air temperature and relative humidity. The changes in the amount of transpiration, air temperature, and relative humidity were estimated for Seogyo-dong area which has a lot of floating population in Seoul, at 2 p.m. in dry day in July and August. On average, the transpiration of the street tree decreased the temperature 0.3℃ and increased the relative humidity 2.6% in an hour. As a result of these changes in temperature and humidity, the discomfort index rose mostly(0.036 on average). It was always get rise especially on the day when the discomfort index was above 80(0.05 on average). However, compared with the significant change in temperature and humidity, the variation of the discomfort index itself was very slight(up to 0.107). Therefore, the effect of transpiration by the street trees might not be effective in the planning to improve the thermal environment(especially on the day when the discomfort index is high). It is necessary to select the species of trees and planting location considering the cooling effect of shade formation synthetically.

Estimation Carbon Storage of Urban Street trees Using UAV Imagery and SfM Technique (UAV 영상과 SfM 기술을 이용한 가로수의 탄소저장량 추정)

  • Kim, Da-Seul;Lee, Dong-Kun;Heo, Han-Kyul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.6
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    • pp.1-14
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    • 2019
  • Carbon storage is one of the regulating ecosystem services provided by urban street trees. It is important that evaluating the economic value of ecosystem services accurately. The carbon storage of street trees was calculated by measuring the morphological parameter on the field. As the method is labor-intensive and time-consuming for the macro-scale research, remote sensing has been more widely used. The airborne Light Detection And Ranging (LiDAR) is used in obtaining the point clouds data of a densely planted area and extracting individual trees for the carbon storage estimation. However, the LiDAR has limitations such as high cost and complicated operations. In addition, trees change over time they need to be frequently. Therefore, Structure from Motion (SfM) photogrammetry with unmanned Aerial Vehicle (UAV) is a more suitable method for obtaining point clouds data. In this paper, a UAV loaded with a digital camera was employed to take oblique aerial images for generating point cloud of street trees. We extracted the diameter of breast height (DBH) from generated point cloud data to calculate the carbon storage. We compared DBH calculated from UAV data and measured data from the field in the selected area. The calculated DBH was used to estimate the carbon storage of street trees in the study area using a regression model. The results demonstrate the feasibility and effectiveness of applying UAV imagery and SfM technique to the carbon storage estimation of street trees. The technique can contribute to efficiently building inventories of the carbon storage of street trees in urban areas.

Selecting Core Areas for Conserving Riparian Habitat Using Habitat Suitability Assessment for Eurasian Otter (서식지 적합성 평가를 이용한 수변지역 핵심 보전지역 선정 - 수달을 대상으로 -)

  • Jeong, Seunggyu;Park, Chong Hwa;Woo, Donggul;Lee, Dong Kun;Seo, Changwan;Kim, Ho Gul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.2
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    • pp.19-32
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    • 2015
  • In Korea, significant riparian areas have been developed due to river maintenance projects. Introduction of new riparian facilities can negatively affect wildlife in the riparian areas. This study focuses on selecting core conservation areas for Eurasian Otter(Lutra lutra) to support decision making process for development of riparian areas. For the study, first of all, field data of study site were collected by field surveys. Secondly, stream naturalness was assessed to understand physical environments of the study sites. Thirdly, habitat suitability was assessed using occurrence data of Eurasian Otter and environmental data. Lastly, core areas for conservation was selected by comparing and synthesizing stream naturalness map and habitat suitability map. The selected core areas showed several characteristics. The number of artificial facilities is low in the core areas. Rocks which are preferred by Eurasian Otter to eat and excrete are plentiful in the core areas. Also, the ratio of adjacent farmland is high. Based on the analyses, it is expected that this study can contribute to decision making process for environmental spatial plans to better conserve habitats of Eurasian Otter.

Prediction of Heating and Cooling Energy Consumption in Residential Sector Considering Climate Change and Socio-Economic (기후변화와 사회·경제적 요소를 고려한 가정 부문 냉난방 에너지 사용량 변화 예측)

  • Lee, Mi-Jin;Lee, Dong-Kun;Park, Chan;Park, Jin-Han;Jung, Tae-Yong;Kim, Sang-Kyun;Hong, Sung-Chul
    • Journal of Environmental Impact Assessment
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    • v.24 no.5
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    • pp.487-498
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    • 2015
  • The energy problem has occurred because of the effects of rising temperature and growing population and GDP. Prediction for the energy demand is required to respond these problems. Therefore, this study will predict heating and cooling energy consumption in residential sector to be helpful in energy demand management, particularly heating and cooling energy demand management. The AIM/end-use model was used to estimate energy consumption, and service demand was needed in the AIM/end-use model. Service demand was estimated on the basis of formula, and energy consumption was estimated using the AIM/end-use model. As a result, heating and cooling service demand tended to increase in 2050. But in energy consumption, heating decreased and cooling increased.

Phylogenetics and Gene Structure Dynamics of Polygalacturonase Genes in Aspergillus and Neurospora crassa

  • Hong, Jin-Sung;Ryu, Ki-Hyun;Kwon, Soon-Jae;Kim, Jin-Won;Kim, Kwang-Soo;Park, Kyong-Cheul
    • The Plant Pathology Journal
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    • v.29 no.3
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    • pp.234-241
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    • 2013
  • Polygalacturonase (PG) gene is a typical gene family present in eukaryotes. Forty-nine PGs were mined from the genomes of Neurospora crassa and five Aspergillus species. The PGs were classified into 3 clades such as clade 1 for rhamno-PGs, clade 2 for exo-PGs and clade 3 for exo- and endo-PGs, which were further grouped into 13 sub-clades based on the polypeptide sequence similarity. In gene structure analysis, a total of 124 introns were present in 44 genes and five genes lacked introns to give an average of 2.5 introns per gene. Intron phase distribution was 64.5% for phase 0, 21.8% for phase 1, and 13.7% for phase 2, respectively. The introns varied in their sequences and their lengths ranged from 20 bp to 424 bp with an average of 65.9 bp, which is approximately half the size of introns in other fungal genes. There were 29 homologous intron blocks and 26 of those were sub-clade specific. Intron losses were counted in 18 introns in which no obvious phase preference for intron loss was observed. Eighteen introns were placed at novel positions, which is considerably higher than those of plant PGs. In an evolutionary sense both intron loss and gain must have taken place for shaping the current PGs in these fungi. Together with the small intron size, low conservation of homologous intron blocks and higher number of novel introns, PGs of fungal species seem to have recently undergone highly dynamic evolution.

Assessment of National and Regional Plans Using Integrated Management Index of Korea National Planning and Environmental Planning for Present Status Evaluation (국토계획과 환경계획 통합관리 지표의 적용을 통한 통합관리 현황 평가)

  • Heo, Han-Kyul;Lee, Dong-Kun;Sung, Hyun-Chan;Heo, Min-Ju;Park, Jin-Han
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.4
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    • pp.81-91
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    • 2019
  • Integrated management of Korea national and environmental planing for sustainable development is suggested, and basic research is needed. In this study, national and regional plans were assessed using 'integrated management index of Korea national planning and environmental planning' to grasp the current status of integrated management on Korea national planning and environmental planning. As a result of the assessment, it was found that both national and regional plans need to improve considering the natural ecology part and water resource and quality part. In addition, it was derived that the detailed contents of the indicator can not be reflected according to the characteristics in the higher-level plan. Therefore, it has been found necessary to include proclamatory contents so as to be able to establish a detailed plan that reflects environmental goals in the lower-level plan.

Effects of Climate Change on Outdoor Water Activity : The Case of Hangang Park Swimming Pool in Seoul (기후변화가 야외 물놀이 활동에 미치는 영향 : 한강시민공원 수영장을 대상으로)

  • Kim, Song-Yi;Park, Jin-Han;Lee, Dong-Kun
    • Journal of Climate Change Research
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    • v.6 no.3
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    • pp.193-201
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    • 2015
  • The aim of this study is to find preferred climate condition for outdoor water activity and to estimate future change of preferred season for the activity following the climate change. We chose urban public swimming pools, Hangang park swimming pools, which do not have any attractions except pools and allow people to make decision to visit pools in the morning solely based on the weather conditions as study sites. We identified the preferred climate conditions by analyzing the relationship between number of visitors and temperature, wind chill temperature and discomfort indexes. According to the result, the preferred temperature range was from $23.51^{\circ}C$ to $37.56^{\circ}C$, the wind chill temperature range was from $25.90^{\circ}C$ to $39.43^{\circ}C$, the discomfort index range was from 71.61 to 88.98 and the precipitation range was below 22.8 mm per day. When the temperature range is applied as the preferred season, in present, the length of the season is 127 days, from end of May to end of September. However, if temperature increase resulting from lower emission scenario (RCP 6.0), the season would be extended to 162 days, from early May to middle of October. If temperature is increasing under high emission scenario (RCP 8.5), the length of the season would be extended to 173 days from early May to end of October. In addition, the period of between end of July and early August, which is currently the most preferred season, would not be favored anymore due to high temperature. The result of this study further suggests the necessity of climate change adaptation activities.

Analysis of the potential landslide hazard after wildfire considering compound disaster effect (복합재해 영향을 고려한 산불 후 산사태 잠재적 피해 위험도 분석)

  • Lee, Jong-Ook;Lee, Dong-Kun;Song, Young-Il
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.1
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    • pp.33-45
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    • 2019
  • Compound disaster is the type that increases the impact affected by two or more hazard events, and attention to compound disaster and multi-hazards risk is growing due to potential damages which are difficult to predict. The objective of this study is to analyze the possible impacts of post-fire landslide scenario quantitatively by using TRIGRS (Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Analysis), a physics-based landslide model. In the case of wildfire, soil organic material and density are altered, and saturated hydraulic conductivity decrease because of soil exposed to high temperature. We have included the change of soil saturated hydraulic conductivity into the TRIGRS model through literature review. For a case study, we selected the area of $8km^2$ in Pyeongchang County. The landslide modeling process was calibrated before simulate the post-wildfire impact based on landslide inventory data to reduce uncertainty. As a result, the mean of the total factor of safety values in the case of landslide was 2.641 when rainfall duration is 1 hour with rainfall intensity of 100mm per day, while the mean value for the case of post-wildfire landslide was lower to 2.579, showing potential landslide occurrence areas appear more quickly in the compound disaster scenario. This study can be used to prevent potential losses caused by the compound disaster such as post-wildfire debris flow or landslides.