• Title/Summary/Keyword: Urban tree

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Application of a Decision Tree to Alternative Plans for the Urban Flood Mitigation (Decision Tree를 이용한 도시유역홍수방어 대안 도출)

  • Byeon, Sung-Ho;Kang, Hyun-Jik;Han, Jeong-Woo;Ahn, Jae-Hyun;Kim, Tae-Woong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.726-730
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    • 2007
  • 우리나라는 6월부터 9월까지의 우기에 강우가 집중 발생하는 기상특성으로 인해 자연재해의 95% 이상이 집중호우와 태풍에 의한 풍수해로 집계되고 있을 만큼 홍수피해에 취약하며, 오래전부터 홍수방어에 대한 구조적 대책이 시행되어왔다. 본 연구의 목적은 의사결정기법인 Decision Tree(의사결정나무)를 활용하여 유역종합치수계획의 구조적 홍수방어 최적대안 선정을 위한 후보대안들을 제시하여 홍수저감능력을 효율적으로 극대화 하는데 그 목적이 있다. 본 연구는 유역이 가지고 있는 치수적 기능을 최대한 살리고 상 하류의 유기적인 방어 기능을 도모하고자 하였으며, 또한 도시유역 홍수방어 대안 조합 지침을 마련하여 실무에 적용가능한 안을 제시하였다.

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Soil Environment's Impact on the Growth of Pinus thunbergii by Season in Urban Forests (도시림의 계절별 토양환경이 곰솔의 생육에 미치는 영향)

  • Kim, Seok-Kyu
    • Journal of Environmental Impact Assessment
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    • v.20 no.4
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    • pp.455-464
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    • 2011
  • The purpose of this study is to clarify correlations between soil environments and the growth of trees in forests and thereon analyze effects of seasonal changes in such environments on such growth. To determine seasonal factors of soil affecting the Tree Vitality of Pinus thunbergii, first of all, the study designated the Tree Vitality as a dependent variable and soil hardness, moisture, pH, K, Na, Mg and Ca as independent variables. Then the study performed Pearson's coefficient analysis. To clarify what soil factors influence the seasonal growth of Pinus thunbergii multiple regression analysis is carried out, and findings are as follow; the growth of Pinus thunbergii was basically influenced by pH, followed by soil hardness in spring, K, followed by moisture in summer, and by soil hardness in winter. However, no soil factors affected the vitality at the significance level of 5% for t.

Urban Forest Monitoring in Korea since 1991: Case Study on Daegu Metropolitan City

  • Kwon, Jino;Cho, HyunJe;Choi, MyoungSnb;Park, Chan-Ryul;Sung, Joo-Han;Cho, Jae-Hyoung;Kim, Sunhee;Park, Jonggyun;Oh, Jeong-Hak
    • Journal of Korean Society of Forest Science
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    • v.95 no.5
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    • pp.591-594
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    • 2006
  • To have better urban forests in future we are focusing on two major issues like other countries. How we could have more urban forest-quantitative approach-against the expanding of urbanization, and how we could produce better urban forest-qualitative approach-to give a chance in contact with better nature for urban people. Prime surveys on urban forests have been carried out in 6 major cities since 1991, and the city of Daegu which is located on the east southern area of Korea have been case studied for qualitative approaches during last 3 years. Major species of the remnant forests were Pinus densiflora, Pinus rigida, Pinus thunbergii and Robinia pseudoacacia. Approximately 20% of the surveyed forests were lost their structure as forests caused by illegal farming, facilities and as the bare ground by excessive visitors. Generally speaking the condition of forests for biotope was very poor in overall. From two years data of monitoring of birds, we found that wooded parkways and woodland squares had more species than street tree areas. Nests were found mainly on the branch of Zelkova serrata, Pinus densiflora and Quercus myrsinaefolia. The size of urban forests mainly determined the species richness of birds. According to the oxygen output and carbon input by photosynthesis measurement, the capability was in order of Platanus occidentalis, Zelkova serrata and Ginko biloba. Air conditioning effects of trees through transpiration measurement was found and the quality of forests also related to the reducing of urban heat-island.

Analyzing the Cooling Effect of Urban Green Areas by Using the Multiple Observation Network in the Seonjeongneung Region of Seoul, Korea (최근 2년간 서울 선정릉 지역의 복합센서 관측망을 활용한 녹지 냉각효과 분석)

  • Kim, Geun-Hoi;Lee, Young-Gon;Lee, Dae-Geun;Kim, Baek-Jo
    • Journal of Environmental Science International
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    • v.25 no.11
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    • pp.1475-1484
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    • 2016
  • To analyze the cooling effect of urban green areas, we conducted micrometeorological measurements in these areas and their surroundings in Seoul, Korea. From the average hourly temperature measurements through each month for the last two years (March 2013 to February 2015), we found that the maximum temperature difference between urban and green areas was about $2.9^{\circ}C$ at 16:00 LST in summer, and the minimum was about $1.7^{\circ}C$ at 22:00 LST in winter. In summer, the temperature difference was the largest during the day, rather than at night, due mainly to shading by the tree canopy. The specific humidity difference between the two areas was about $1.5g\;kg^{-1}$ in summer, and this decreased in the winter. The specific humidity difference between urban and green areas in summer is relatively large during the day, due to the higher evapotranspiration level of biologically active plants.

Performance Assessment of Three Turfgrass Species, in Three Different Soil Types, and their Responses to Water Deficit in Reinforced Cells, Growing in the Urban Environment

  • Ow, L.F;Ghosh, S.;Chin, S.W.
    • Weed & Turfgrass Science
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    • v.4 no.4
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    • pp.338-347
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    • 2015
  • Reinforcement cells are used to aid grass growth and taken together, this serves to extend greenery beyond the conventional spaces of lawns, tree pits, gardens, and parks, and is advantageous to urban cities since space for greening is often limited. Drought has variable effects on plant life and the resilience of turf to drought resistance also varies with species. Changes in photosynthetic ability were more pronounced for media rather than grass species. The media of sand without organic matter was found to be least suited for drought resistance. Normalized difference vegetation index (NDVI) and digital image analysis (DIA) data were generally in favour of Zoysia species as oppose to A. compressus. In A. compressus, selective traits such as, a more extensive root system and lower specific leaf area (SLA) were not an underlying factor that assisted this grass with enhanced drought resistance. Generally, WUE was found to be strongly related to plant characterises such as overall biomass, photosynthetic features as well as the lushness indexes, and specific leaf area. This study found a strong relationship between WUE and a suite of plant characteristics. These traits should serve as useful selection criteria for species with the ability to resist water stress.

A Study on the Method of Urban Planning for Adaptation to Climate Change (기후변화 적응을 위한 도시계획 방안 연구)

  • Lee, Sung Hee;Kim, Jong Kon
    • Journal of Climate Change Research
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    • v.5 no.3
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    • pp.257-266
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    • 2014
  • This study aims to understand abnormal climate caused by impacts of climate change and to suggest the direction of urban planning focusing on adaptation to climate change. The study consists of theory consideration and case study(Chicago, Philadelphia, Seattle). As a result, the main impacts of climate change faced by urban areas are heat wave, precipitation, and drought. To prevent these impacts, it is important to prepare methods of urban planning as followings: planning for land use, park and green considering the climate patterns, establishing and managing water resources systems similar to the nature, securing renewable energy resources, and transportation facilities and exterior space with proof against climate. It is especially necessary to introduce infrastructures related to storm water, green roof, shading tree planting, green space, and permeable pavement. Finally, in order to realize urban planning for adaptation to climate change, it is needed to make the detailed and specific goal and strategy for the climate change adaptation plan and to extend the scope from the goals to an action plan, a detailed plan, and a design guideline.

A Study on the Effect of Air Temperature and Ground Temperature Mitigation from Several Arrangements of Urban Green (도시녹지의 기온 및 지온 완화효과에 관한 연구)

  • 이은엽;문석기;심상렬
    • Journal of the Korean Institute of Landscape Architecture
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    • v.24 no.1
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    • pp.65-78
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    • 1996
  • To study the temperature mitigation effects from urban green, several arrangements of green spaces were selected and air/ground temperatures were measured in Chongju city area. The results of this study can be summarized as follows; 1. It was found that the natural ground materials effect more affirmatively on the air and ground temperature than artificial ones do. The best results were recorded from the grass surface presenting highest mitigation effect and lowest daily temperature deviation. 2. Temperature mitigation effects of Tree-Shade on ground are different from season, ground material, and crown-size. Them most effects were found in interlocking block, the least in grass surface among recorded 2 seasons and 3 materials. In case of air temperature, the effects were more or less decreased in most cases. 3. From the survey, it was confirmed that the smaller urban greens can do its role of temperature mitigation as larger ones does. In case of this study, the effect was recorded about 2.3$^{\circ}C$.

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A Graph-based Model for RSUs Deployment in Vehicular Networks by Considering Urban and Network Limitations and QoS Requirements of Service Advertisement and Discovery

  • Balouchzahi, Nik Mohammad;Fathy, Mahmood;Akbari, Ahmad
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.5
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    • pp.1662-1681
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    • 2015
  • The efficient send and receive of information in VANET improves the efficiency of the safety and traffic services advertisment and discovery. However, if the V2V is the only communication system used, the restrictions of the urban environment and network drop the performance of VANET. In order to improve the performance of the network, it is necessary to use V2I communication as well as V2V communication. Therefore, RSUs must be placed in the environment. However due to the high costs of placement, the full coverage of the environment would not be possible. Therefore, it is necessary to optimally install a limited number of RSUs in the environment.

A Study on the Waterways in Traditional Urban Area of Late 1960s Cheongju Korea (1960년대 후반 청주 도심 내 물길에 관한 연구)

  • Kim, Tai-Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.2
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    • pp.27-34
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    • 2015
  • As part of the waterway restoration to renew traditional urban area, this paper is to assume and research Gyoseocheon(Gyoseo waterway) in Late 1960s Cheongju Korea. The main stream of Gyoseocheon flew from Sangjwagol(the head of the valley) of Uam Mt. to the north gate under Cheongju castle at first, and meandering from Sangdang Park, flew through Sudongseongdang and Bangadari Road to Musimcheon since open railroad of 1920s. This waterway, the eco-friendly figure of Gyoseocheon, that flew to inside the downtown with a planted tree and that is open space was so. The sub stream of Gyoseocheon originated in Seoundong and Tapdong were divided into two parts. One was to join the main stream of Gyoseocheon on Sangdang Park via Munhwadong, and the other was to join the sub stream of Musimcheon at northwest corner via south and west gate of Cheongju castle. This waterway as branch sewer were built into the road culvert.