2022-05-03 イリノイ大学アーバナ・シャンペーン校
屋上庭園やエコルーフとしても知られるグリーンルーフは、通常、屋根の上に土で育てた植物の層があり、さらに防水、構造支持、断熱のための材料が使用されています。リード大学は、イリノイ大学およびポートランド州立大学と共同で、屋上緑化の利点と、ポートランド市民が市内に屋上緑化を増やすためにいくら支払ってもよいと考えるかを調査しました。
＜関連情報＞
- https://aces.illinois.edu/news/green-roofs-are-worth-cost-urban-residents
- https://www.sciencedirect.com/science/article/pii/S0169204622000755
屋上緑化の公共的メリットの評価 Valuing the public benefits of green roofs
Noelwah R.Netusil,LaurenLavelle,SahanDissanayake,Amy W.Ando
Landscape and Urban Planning Published:11 April 2022
DOI:https://doi.org/10.1016/j.landurbplan.2022.104426
Abstract
Green roofs are being incorporated into stormwater management programs around the world. While numerous studies have estimated the private benefits to the owners and residents of buildings with green roofs, the value of the multiple public benefits received by non-building residents are less well known. We use a choice experiment survey to estimate the public benefits for a proposed green roof program in Portland, Oregon, USA. These benefits include reduced combined sewer overflows, reduced urban heat island effects, and an increase in pollinators such as birds, bees and butterflies. Past investments in stormwater infrastructure have exposed some residents to poor water quality and urban flooding, so we also explore if respondents’ willingness to pay varies based on where new green roofs are located. Across models, the largest estimated benefit in our study area is from a reduction in combined sewer overflows. Model results also show that respondents prefer to not fully concentrate new green roofs in Portland’s Central City area, which is where most green roofs are currently located. Total willingness to pay estimates for the 1-year program range from around $202 to $442 per household, or $54.4 to $116.8 million for the city of Portland, Oregon, depending on program characteristics.
