QUIETE: A scheme for a new index of the environmental quality of green areas

Abstract

Notwithstanding the green areas are important for preserving and promoting the health of population, they are often exposed to noise pollution, especially in urban areas. However, the perceived quality of a green area does not depend only by its sonic environment, as all the human senses contribute to form the individual appraisal together with other features of the area. Thus, an holistic approach is required like that offered by the soundscape approach. The present paper proposes the scheme of a new index, QUIETE, to quantify the quality of a public park, taking into account its perceived overall quality and the relative sound level determined by the difference between the noise descriptor LA (i.e. LAeq, LA50,⋯) and a reference level Lref. By the QUIETE index it is easy to identify the areas requiring noise mitigation actions, and provide understandable information to the users of the park on the areas for their enjoyable fruition. The formulation of the QUIETE index is rather flexible and the reference level Lref has to be fixed considering the objective to accomplish. To evaluate the feasibility and potential of QUIETE, it has been applied to the data collected in 8 urban parks in Milan and Rome with different location (from downtown to suburban area) and size. The Lref value has been set at the noise limit issued by current Italian legislation for green areas (LAeq = 50 dBA for day-time). A "tentative" rating scale for QUIETE is also proposed and its values are reported by a colored scale on the map of the park to summarize the data and to provide information easy to be understood by non-experts.