Numerical study of the impact of vegetation coverings on sound levels and time decays in a canyon street model

Given a constantly increasing urban population, the mitigation of environmental impacts caused by urbanization has become a critical concern. Sprawling cities accelerate the phenomenon of soil sealing, whose impacts relative to climatology, water cycle and ecology are substantial. The VegDUD project, which provides the framework for the present paper, lays out a possible alternative for limiting these deleterious effects through focusing on the role of vegetation in promoting sustainable urban development. The study presented herein addresses the beneficial effect of greening building facades and rooftops in terms of both acoustic level and sound-decay time indicators at low frequency third-octave bands. This is carried out through numerical simulations in the time-domain of sound propagation in a canyon street of infinite length for various scenarios of surface vegetalization. Numerical predictions show a more significant effect in the upper part and outside the street, depending on the location of the vegetalized surfaces, frequency bands and number of reflections on the treated materials. (C) 2014 Elsevier B.V. All rights reserved.