Cost-Benefit Analyses of Tree Belts for Noise Reduction - Including Aesthetic and Amenity Values

摘要

The noise reduction effects of using a tree belt to protect 19 buildings exposed to road traffic have been calculated. Given a context where a large number of residents benefiting from the measure and accumulation of substantial noise reductions over many years, the benefits can be substantial. A noise reduction of one dBA has for long been given an economic unit value and we can thus obtain an accumulated value for the summed up noise benefits for all residents. However, corresponding economic unit values for the improvement in area amenity/aesthetics of introducing greenery in the form of a tree belt is missing. Without such values, standard economic analyses are only partial, implicitly disregarding the amenity /aesthetic aspects of green measures, effectively setting the value of such benefits to zero. To improve on this situation we have collaborated in the HOSANNA project to obtain initial and tentative unit value estimates based on a literature survey. Coupled with initial cost estimates for the planting and maintenance of the tree belt, we calculate the economic viability of using vegetation in situations where this could be an option. Since cost, benefit and effect estimates are associated with uncertainties we use Monte Carlo simulations to obtain an impression of how robust our estimates of Benefit-Cost Ratios and other result indicators are.