Valuation of greenery and green areas: An attempt at a classification according to types and sizes

摘要

The soundscape perspective has brought a new awareness of the direct and indirect effects of vegetation on the propagation of sounds in outdoor areas, parks, and urban canyons. However, green roofs and walls, trees, bushes and other vegetation also have important non-acoustic effects. Soundscape research thus needs to take into account aesthetics, air quality, and other environmental effects. One challenge is to integrate the results of some decades of non-acoustic research on the value of green areas, recreational and restorative qualities, aesthetics, and biodiversity into soundscape design, and incorporate these non-acoustic properties in the overall economic assessment of noise control and soundscape improvement measures. Valuation of greenery and green areas, as well as changes in noise exposure, usually rely on hedonic pricing methods, and are usually expressed as an percentage of the dwelling prices. In this paper we go through a varied literature presenting economic value estimates of single trees or lines of trees in streets, and of green walls (vertical gardens) and green roofs. These types of greenery and green areas have an impact on the soundscape (sound propagation). Whereas valuation of soundscape changes directly or indirectly can be related to equivalent decibel changes, and thus given a unit price, e.g., EUR/dB(A), there is no readily applicable unit price for greenery and green areas. In valuation studies each case is considered unique. Acknowledging the theoretical and practical objections and challenges to unit pricing of greenery and green areas, we nevertheless apply a practitioner approach by proposing initial classification and unit valuation based on greenery area size.