• Title/Summary/Keyword: wind effect index

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Analysis of Thermal Environment Modification Effects of Street Trees Depending on Planting Types and Street Directions in Summertime Using ENVI-Met Simulation (ENVI-Met 시뮬레이션을 통한 도로 방향별 가로수 식재 형태에 따른 여름철 열환경 개선 효과 분석)

  • Lim, Hyeonwoo;Jo, Sangman;Park, Sookuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.2
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    • pp.1-22
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    • 2022
  • The modification effects of street trees on outdoor thermal comfort in summertime according to tree planting types and road direction were analyzed using a computer simulation program, ENVI-met. With trees, the air temperature and wind speed decreased, and the relative humidity increased. In the case of mean radiant temperature (Tmrt) and human thermal sensation, physiological equivalent temperature (PET) and universal thermal climate index (UTCI), there was a decrease during the daytime. The greatest change among the meteorological factors by trees happened in Tmrt, and PET and UTCI showed similar patterns with Tmrt·The most effective tree planting type on thermal comfort modification was low tree height, wide tree crown, high leaf area index, and narrow planting interval (LWDN). Tmrt, PET and UTCI showed a large difference depending on shadow patterns of buildings and trees according to solar altitude and azimuth angles, and building locations. When the building shade areas increased, the thermal modification effect by trees decreased. In particular, results on the east and west sidewalks showed a large deviation over time. When applying the LWDN, the northwest, west and southwest sidewalks showed a significant reduction of 8.6-12.3℃ PET and 4.2-4.5℃ UTCI at 10:00, and the northeast, east and southeast sidewalks showed 8.1-11.8℃ PET and 4.4-5.0℃ UTCI at 16:00. On the other hand, when the least effective type (high tree height, narrow tree crown, low leaf area index, and wide planting interval) was applied, the maximum reduction was up to 1.8℃ PET and 0.9℃ UTCI on the eastern sidewalks, and up to 3.0℃ PET and 0.9℃ UTCI on the western ones. In addition, the difference in modification effects on Tmrt, PET and UTCI between the tree planting types was not significant when the tree effects were reduced by the effects of buildings. These results can be used as basic data to make the most appropriate street tree planting model for thermal comfort improvement in urban areas in summer.

Analysis of Human Thermal Environment in an Apartment Complex in Late Spring and Summer - Magok-dong, Gangseo-gu, Seoul- (아파트 단지의 늦봄·여름철 인간 열환경 분석 - 서울특별시 강서구 마곡동 -)

  • Park, Sookuk;Hyun, Cheolji;Kang, Hoon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.1
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    • pp.68-77
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    • 2022
  • The human thermal environment in an apartment complex located in Seoul was quantitatively analyzed to devise methods to modify human heat-related stresses in landscape and urban planning. Microclimatic data (air temperature, relative humidity, wind speed, and short- and long-wave radiation) were collected at 6 locations [Apt-center, roof (cement), roof (grass), ground, playground, and a tree-lined road] in the late spring and summer, and the data were used to estimate the human thermal sensation, physiological equivalent temperature (PET) and universal thermal climate index (UTCI). As a result, the playground location had the highest thermal environment, and the roof (grass) location had the lowest. The mean difference between the two locations was 0.8-1.1℃ in air temperature, 1.8-4.0% in relative humidity, and 7.5-8.0℃ in mean radiant temperature. In open space locations, the wind speed was 0.4-0.5 ms-1 higher than others. Also, a wind tunnel effect happened at the Apt-center location during the afternoon. For the human thermal sensation, PET and UTCI, the mean differences between the playground and roof (grass) locations were: 5.2℃ (Max. 11.7℃) in late spring and 5.4℃ (Max. 18.1℃) in summer in PET; and 3.0℃ (Max. 6.1℃) in late spring and 2.6℃ (Max. 9.8℃) in summer in UTCI. The mean differences indicated a level change in PET and 1/2 level in UTCI, and the maximum differences showed greater changes, 2-3 levels in PET, and 1-1.5 levels in UTCI. Moreover, the roof (grass) location gave 4.6℃ PET reduction and a 2.5℃ UTCI reduction in late spring, and a 4.4℃ PET reduction and a 2.0℃ UTCI reduction in the summer when compared with the roof (cement) location, which results in a 2/3 level change in PET and a 1/3 level in UTCI. Green infrastructure locations [roof (grass), ground, and a tree-lined road] were not statistically significant in the reduction of PET and UTCI in thermal environment modifying effects. The implementation of green infrastructure, such as rooftop gardens, grass pavement, and street tree planting, should be adopted in landscape planning and be employed for human thermal environment modification.

Research Trends of Randomized Controlled Trials on Herbal Medicine Treatment for Atopic Dermatitis-Focusing on CNKI (아토피 피부염의 한약 치료에 대한 무작위대조군연구 중심의 연구 동향 - CNKI를 중심으로)

  • Yang, Geum-Jin;Jo, Eun-hee;Kang, Su-Jin;Hong, Jieun;Shim, Yu-Hwa;Lee, Ju-Hyun;Park, Min-cheol
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.2
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    • pp.102-116
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    • 2020
  • The purpose of this study was to analyze the research trends of randomized controlled trials on herbal medicine treatment for atopic dermatitis in China for the last 5 years. We searched for randomized controlled trials with the intervention of herbal medicine for the treatment of atopic dermatitis in the CNKI (China National Knowledge Infrastructure) from January 2014 to December 2018. For the screening of the paper, we used '特应性皮炎' and '异位性皮炎' which mean atopic dermatitis and search was limited to three areas within Medicine & Public Health: Traditional Chinese Medicine, Traditional Chinese Medicinal Herbs, Combination of Traditional Chinese Medicine with Western Medicine. Among the 136 searched studies, we selected a total of 34 studies and analyzed a year of publication, subject characteristics, study design and intervention, prescribed herbal medicine and herbs, pattern identification, evaluation criteria, and outcomes. Longmu decoction (龍牡湯) and Polia Sclerotium (茯笭) was the most frequently prescribed medicine and herb. The most commonly used pattern identification was Blood deficiency and Wind-dryness (血虛風燥), and among them, the most frequently prescribed herb is Rehmanniae Radix (生地黃). In most studies using the total effectiveness and SCORAD index as an outcome measure, the herbal medicine treatment group showed statistically better results than the control group. As a result of the safety assessment, the herbal medicine treatment group was reported having significantly fewer side effects compared to the control group. Hence, it was confirmed that the intervention including herbal medicine had a significant effect on atopic dermatitis. This study would be able to provide the basis of clinical research on atopic dermatitis and applied to the treatment of atopic dermatitis.

Study on the Ecological Restoration of Rock-exposed-cut-slope by Natural Topsoil Restoration Methods : In Case of Won-Ju Experiment (자연표토 복원공법에 의한 암절취비탈면의 생태적 복원에 관한 연구 : 원주사례지역을 중심으로)

  • Nam, Sang-Joon;Suk, Won-Jin;Kim, Nam-Choon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.2 no.4
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    • pp.54-63
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    • 1999
  • This study was conducted to suggest the ecological restoration and environmentally friendly revegetation technology for the rock-exposed cut-slopes by the Natural Topsoil Restoration Methods (NTRM) with the following restoration objectives; (1) prevention or reduction of wind and water erosion, (2) provision of food and cover for variety of animal species, (3) improvement of the visual or aesthetic quality of the disturbed slopes. On Nov. in 1995, the 5cm thick layer of artificial soil and 2cm thick layer of straw-mulching was attached at rock-exposed cut-slopes by NTRM without using anchor wire and anchor pin. The main results during four years surveying on the ground-coverage effect, plant growth, species diversity and importance values were summarized as follows. 1. Artificial soil attached at rock exposed cut-slopes was not eroded until recovered by tree and herbaceous vegetation in spite of not using anchor wire and anchor pin. Also it shows low soil hardiness and has almost the same amount of bacteria and fungi with in surrounding natural topsoil. 2. In 'combination for the woody vegetation', Lespedeza cyrtobotrya, Albizzia julibrissin, Rhus chinensis, Indigofera pseudo-tinctoria occupied upper layer vegetation. Since three years after seeding, Indigofera pseudo-tinctoria had overwhelmed the other woody plants and cool season foreign grasses, Erigeron canadensis, Taraxacum mongolicum, Commelina communis, Arundinella hirta (Thunberg) and Oenothera erythrosepala grows at lower part of the vegetation, 3. The heights of the Rhus chinensis grows 1.8m, Indigofera pseudo-tinctoria 2.0m, so it seems that the objectives of woody vegetation with native plants could be accomplished. 4. After 4 years later after seeding in 'combination for the herbaceous vegetation', the most dominant plant was Indigofera pseudo-tinctoria, the next was in order of cool-season grasses, Taraxacum mongolicum, Erigeron canadensis, lxeris dentata (Thunberg), Oenothera erythrosepala, Arundinella hirta (Thunberg). The diversity index in 'combination for woody vegetation' was higher than that in 'combination for the herbaceous vegetation'. The tendency of the intrusion of secondary succession plants was more effective in 'combination for the herbaceous vegetation' than in 'combination for the woody vegetation'.

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Alleviation Effect of Pear Production Loss Due to Frequency of Typhoons in the Main Pear Production Area (배 특화지역에서의 태풍내습 빈도에 의한 낙과 피해 경감 효과)

  • Jeong, Jae Won;Kim, Seung Gyu
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.2
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    • pp.43-53
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    • 2017
  • This study aims to analyze the effect of typhoons on pear production. Pears are typical fruits that are vulnerable to typhoon damages, so typhoons are negatively associated with pear productivity. However, relatively less pear damages by typhoons in the main pear production area, comparing to the average in Korea, have been reported. The main production area seems to adopt better agricultural techniques or practices to cope with natural disasters such as typhoons. Thus, this study tests the hypothesis that there are differences of production losses due to typhoons between the main pear production area and the rest using the stochastic frontier analysis. The main production area is defined by Location Quotient Index (LQI), and we found that LQI had a significant effect to decrease the productivity losses in the main production areas, which shows that those production areas alleviated the pear production loss due to typhoons.

Heavy Metal Contamination around the Abandoned Au-Ag and Base Metal Mine Sites in Korea (국내 전형적 금은 및 비(base)금속 폐광산지역의 중금속 오염특성)

  • Chon Hyo-Taek;Ahn Joo Sung;Jung Myung Chae
    • Economic and Environmental Geology
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    • v.38 no.2 s.171
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    • pp.101-111
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    • 2005
  • The objectives of this study we to assess the extent and degree of environmental contamination and to draw general conclusions on the fate of toxic elements derived from mining activities in Korea. 인t abandoned mines with four base-metal mines and four Au-Ag mines were selected and the results of environmental surveys in those areas were discussed. In the base-metal mining areas, the Sambo Pb-Zn-barite, the Shinyemi Pb-Zn-Fe, the Geodo Cu-Fe and the Shiheung Cu-Pb-Zn mine, significant levels of Cd, Cu, Pb and Zn were found in mine dump soils developed over mine waste materials, tailings and slag. Furthermore, agricultural soils, stream sediments and stream water near the mines were severely contaminated by the metals mainly due to the continuing dispersion downstream and downslope from the sites, which was controlled by the feature of geography, prevailing wind directions and the distance from the mine. In e Au-Ag mining areas, the Kubong, the Samkwang, the Keumwang and the Kilkok mines, elevated levels of As, Cd, Cu, Pb and Zn were found in tailings and mine dump soils. These levels may have caused increased concentrations of those elements in stream sediments and waters due to direct dis-charge downstream from tailings and mine dumps. In the Au-Ag mines, As would be the most characteristic contaminant in the nearby environment. Arsenic and heavy metals were found to be mainly associated with sulfide gangue minerals, and mobility of these metals would be enhanced by the effect of oxidation. According to sequential extraction of metals in soils, most heavy metals were identified as non-residual chemical forms, and those are very susceptible to the change of ambient conditions of a nearby environment. As application of pollution index (PI), giving data on multi-element contamination in soils, over 1.0 value of the PI was found in soils sampled at and around the mining areas.