Print Email Facebook Twitter A model to predict the sound reflection from forests Title A model to predict the sound reflection from forests Author Wunderli, J.M. Salomons, E.M. TNO Bouw en Ondergrond Publication year 2009 Abstract A model is presented to predict the reflection of sound at forest edges. A single tree is modelled as a vertical cylinder. For the reflection at a cylinder an analytical solution is given based on the theory of scattering of spherical waves. The entire forest is represented by a line of cylinders placed along the forest edge. The spacing between the cylinders is defined as a function of frequency and geometrical properties to account for contributions from the depth of the forest. As a consequence of this model assumption of a single line of reflecting cylinders, a variable segmentation of the forest edge and the use of look-up tables for the reflectivity of a single cylinder, a straightforward calculation procedure can be achieved, which allows an implementation in engineering sound propagation models. A validation of the model showed good agreement with measurements. Nevertheless the measurements indicated a tendency to overestimate the levels at frequencies above 1 kHz. Further measurements should be conducted to shed light on this question and to expand additional aspects such as meteorological influences on forest reflections and the behaviour over hilly terrain where a vertical directivity pattern will become important. © S. Hirzel Verlag EAA. Subject Urban DevelopmentAcoustics and AudiologyBuilt EnvironmentModelsReflectionTable lookupAnalytical solutionsCalculation proceduresDirectivity patternsForest edgesFunction of frequenciesGeometrical propertiesLook-up tablesMeteorological influencesModel assumptionsSound propagationSound reflectionsSpherical wavesVertical cylindersCylinders (shapes) To reference this document use: http://resolver.tudelft.nl/uuid:137891ce-6f27-4503-bd4e-2a7f6ae93dee TNO identifier 241344 ISSN 1610-1928 Source Acta Acustica united with Acustica, 95 (1), 76-85 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.