Urban noise functional stratification for estimating average annual sound level

Abstract

Road traffic noise causes many health problems and the deterioration of the quality of urban life; thus, adequate spatial noise and temporal assessment methods are required. Different methods have been proposed for the spatial evaluation of noise in cities, including the categorization method. Until now, this method has only been applied for the study of spatial variability with measurements taken over a week. In this work, continuous measurements of 1 year carried out in 21 different locations in Madrid (Spain), which has more than three million inhabitants, were analyzed. The annual average sound levels and the temporal variability were studied in the proposed categories. The results show that the three proposed categories highlight the spatial noise stratification of the studied city in each period of the day (day, evening, and night) and in the overall indicators (L(And), L(Aden), and L(A24)). Also, significant differences between the diurnal and nocturnal sound levels show functional stratification in these categories. Therefore, this functional stratification offers advantages from both spatial and temporal perspectives by reducing the sampling points and the measurement time.

Analysis of Sampling Methodologies for Noise Pollution Assessment and the Impact on the Population

“…Three sampling methods were analysed: the grid method [ 42 ], road types established by the Ministry of Transport and Telecommunications of Chile (MTT) [ 46 ], and the categorisation method [ 45 ]. In order to compare the uncertainties using a similar sampling time the same number of sampling points (52) was selected for each measurement method.…”

“…In contrast to previous statistical tests, the receiver operating characteristics analysis ( ROC ) was used to evaluate the discriminative capacity of the MTT road types and of categorisation method to differentiate the sound values of the sampling points between pairs of strata (stratum i versus stratum j ) [ 45 ]. For the categorisation method and for MTT, the strata are the road categories and road types, respectively.…”

“…This has produced significant improvements in both the reduction of the number of sampling points and in the estimation of noise levels in unsampled streets. Its usefulness has mainly been studied in Spanish cities with a wide range of populations: from 2000 to 3,250,000 inhabitants [ 43 , 44 , 45 ]. However, the economic development and urban planning of Chilean cities are different from the European cities analysed with the categorisation method in previous studies.…”

Investigation on clusters stability in DYNAMAP’s monitoring network during Covid-19 outbreak

“…The idea that noise emission from a street generally depends on its activity, its use in the urban context rather than strictly from its geometric characteristics, suggested an approach based on a categorization method for the analysis of urban noise. It lies on the generally accepted assumption that road traffic is the most important source of noise in towns, and can therefore be considered the main cause of its spatial and temporal variability [21][22][23].…”

DYNAMAP – Development of low cost sensors networks for real time noise mapping

“…This is the reason why we decided to approach the sampling issue not inside each functional group (stratified sampling) by firstly statistically analyzing the temporal profiles series, δ ij , in order to obtain homogeneous groups of roads with similar noise behavior. This approach has the advantage of providing a better description of the real behavior of the complex road network of the city of Milan and, therefore, of improving the sampling efficiency [17][18][19][20][21] based upon cluster categorization. We applied an unsupervised clustering analysis to the 24-h hourly normalized level profiles, δ ij , found to be statistically similar to one another.…”