Effect of reducing the street trees in terms of the ratio of green

緑視率から見た街路樹削減効果に関する数理的考察

A large amount of budget is spent on managing street trees, but these years public work-related expenditures that can be spent on the maintenance of them are shrinking. For saving budget, trees are pruned badly so they won't need any pruning for some years, and these trees which lost their functions as street tree lead to urban landscape deterioration. This research will discuss if there is an optimum strategy to cut down managing cost of sideway trees, in other words, to reduce the trees, but still keep ratio of green to a certain degree. The change on ratio of green by reducing trees has effect on two kind of audience: (1) Drivers of vehicles who have relatively fixed point of view; and (2) Pedestrians and other residents whose visual line can be seen as random line.高度成長期以後進んだ都市の街路緑化が，縮小時代ではその剪定とメンテナンスが自治体財政の負担となっている．街路樹の管理費削減のため，強剪定などで対処している自治体は，景観上の問題がみられる．街路樹の維持管理が喫緊の課題となっている．本研究では，緑のインフラの減少時代に向けて，街路樹の削減と緑視率の関係を単純化モデルで分析する．まず，運転者の目線から樹木密度（道路延長あたりの樹木数）と緑視率との関係を考察する．次に，沿道住民の視線をランダムな直線に置き換えて議論する．結論として次の知見が得られた．第一に，樹木密度を半減させても緑視率は半減しない．第二に，高速運転となる道路では，樹間距離を長くしても緑視率は大きく減少しない．第三に，街路樹の伐採方式により，沿道住民視点での緑視率の減少傾向が異なる．

• Record URL:
  https://doi.org/10.11361/journalcpij.50.273
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=Effect+of+reducing+the+street+trees+in+terms+of+the+ratio+of+green&author=X.+Zhang&author=N.+Ishii&author=M.+Amemiya&author=Y.+Osawa&publication_year=2015
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09160647
• Authors:
  • Zhang, Xindi
  • Ishii, Norimitsu
  • Amemiya, Mamoru
  • Osawa, Yoshiaki
• Publication Date: 2015

Language

• English
• Japanese

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 273-278
• Serial:
  • Journal of the City Planning Institute of Japan
  • Volume: 50
  • Issue Number: 3
  • Publisher: City Planning Institute of Japan
  • ISSN: 0916-0647
  • EISSN: 2185-0593
  • Serial URL: https://www.jstage.jst.go.jp/browse/journalcpij/-char/en

Subject/Index Terms

• TRT Terms: Costs; Drivers; Landscape maintenance; Optimization; Pedestrians; Roadside flora; Trees; Visibility
• Subject Areas: Environment; Finance; Highways; Materials; Pedestrians and Bicyclists; Planning and Forecasting; I10: Economics and Administration; I15: Environment; I60: Maintenance; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01579849
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Oct 28 2015 10:20AM