Special Acoustics Area: The Center of the Malaga City (Spain) Fernando López Santos, David Carretero de la Rocha, Isabel Gimenez Anaya, and Ricardo Hernández Molina Citation: Proc. Mtgs. Acoust. 28, 040006 (2016); View online: https://doi.org/10.1121/2.0000520 View Table of Contents: http://asa.scitation.org/toc/pma/28/1 Published by the Acoustical Society of America Articles you may be interested in Laboratory measurements of reflection coefficient from a water-mud interface after varying bottom water salinity Proceedings of Meetings on Acoustics 29, 070001 (2017); 10.1121/2.0000517 The investigation of the method for measuring the low-frequency radiated sound power in a reverberation tank Proceedings of Meetings on Acoustics 29, 070002 (2017); 10.1121/2.0000518 Individual head-related impulse response measurement system with 3D scanning of pinnae Proceedings of Meetings on Acoustics 28, 055007 (2017); 10.1121/2.0000519 Simulating cognitive feedback in the context of binaural scene analysis Proceedings of Meetings on Acoustics 28, 055008 (2017); 10.1121/2.0000522 Relation between violin timbre and harmony overtone Proceedings of Meetings on Acoustics 29, 035001 (2017); 10.1121/2.0000376 Acoustic and structural resonances of the cajon Proceedings of Meetings on Acoustics 25, 035005 (2017); 10.1121/2.0000516
Volume 28 http://acousticalsociety.org/ 22nd International Congress on Acoustics Acoustics for the 21 st Century Buenos Aires, Argentina 05-09 September 2016 Noise: Paper ICA2016-901 Special Acoustics Area: The Center of the Malaga City (Spain) Fernando López Santos and David Carretero de la Rocha SINCOSUR Ingeniería Sostenible S.L, SPAIN, flopez@sincosur.es, dcarretero@sincosur.es Isabel Gimenez Anaya SINCOSUR Ingeniería Sostenible S.L, SPAIN, isabel@sincosur.es Ricardo Hernández Molina Acoustical Engineering Laboratory, Cadiz University, SPAIN, ricardo.hernandez@uca.es An analytical study of the results of central Malaga's strategic noise map, of over 20,000 complaints related to noise pollution, of the city's noise monitoring and of a thorough study of the different noise sources existing in the area shows that the city centre of Malaga is a Special Acoustic Area. Diagnosed noise pollution requires a specific action plan to achieve the noise quality standards. This paper develops an analytical method stressing the need to quantify noise sources from leisure activities and the concentration of people in the street. Published by the Acoustical Society of America 2017 Acoustical Society of America [DOI: 10.1121/2.0000520] Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 1
1. INTRODUCTION Strategic noise maps (SNM) of a town are drawn in accordance with current regulations [1] and define as noise sources those generated by road, air and rail traffic as well as industrial activities, thus painting a picture of the city's annual average noise levels from those sources. Given these results, we can ask ourselves the following question: are the noise problems that people perceive reflected in the SNM? To answer this question, besides the analytical and objective study of the SNM, we carry out a more subjective assessment of the problem of noise pollution based on how it affects the citizens. A. Starting Point The studies conducted by SINCOSUR Ingeniería Sostenible S.L. for the Malaga City Council and related to "SERVICIO DE CONSULTORÍA Y ASISTENCIA TÉCNICA RELATIVA A REVISIÓN Y ACTUALIZACIÓN DE LOS PLANES DE ACCIÓN CONTRA EL RUIDO DE MÁLAGA" [2], with file number 84/14, have allowed us to gain extensive knowledge of the issues brought up by noise pollution in the city of Malaga. The problematic areas, that is, those exceeding the noise levels set in the quality standards, were identified using the noise zoning of the city and the results of the 2nd strategic noise map. [3] Figure 1. Detail of the conflict map of the Malaga metropolitan area. The city centre does not appear as a problematic area since it consists mostly of pedestrian zones. However, among the tasks of the action plan, the complaints and claims regarding noise pollution filed at Malaga's city council [4] (20,315 in 2013 and 2014) were processed following statistical and spatial criteria. This work has allowed us to learn, from both quantitative and qualitative points of view, the citizens' perception of noise pollution problems and to identity problematic areas not shown in the SNM, since these problems are caused by noise sources which are not included in the SNM. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 2
Regarding the total number of filed complaints, we noted that most of them were related to anti-social activities and behaviours (14,188, 70% of the overall claims), followed by those related to neighbour activities (3,204, 16%) and by the hospitality industry (2,413, 12%). The remaining complaints and claims only represent less than 3% of the total number. Of this percentage, only 0.04% is related to the noise sources included in the SNM, i.e. road, rail and air traffic, industrial activities and port operations. B. Special Noise Area The current acoustic regulation defines noise protection zones (NPZ) as "the areas where noise exposure does not meet the quality standards in force". [1] Article 20 of Decree 6/2012, of 17 January, relating to the approval of the noise protection regulations in Andalusia, defines acoustically saturated zones (ASZ) as "the areas in a town where, because of the existence of various activities aimed at the use of establishments and which, despite individually meeting the noise levels set by the current regulation on the noise which is noticeable from the street, due to the concentration of activities and to the people participating in them, the overall noise levels exceed the noise quality standards, when they are above or equal to the nighttime values established in the following chart, according to the zone of noise exposure in which they appear. Table 1. Noise exposure quality standards. 2. OBJECTIVES The main objective of this paper is to develop a thorough characterization and diagnosis of the noise pollution that exists in the city centre of Malaga. A secondary objective is to determine whether the city centre is a special acoustic zone and to propose its categorization as a noise protection zone or as an acoustically saturated zone, devising the corresponding zonal plan for noise pollution which will tackle the needs of the city centre of Malaga. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 3
3. MATERIALS AND METHODS A. Study Area The study area is the historic centre of the city. Figure 2. Study area. B. Available Data The following information is already available in order to develop this research: - Data generated by the environmental noise monitoring system of the city council, from a total of 41 Type I stations. - Geo-tagged and characterized noise-related complaints and claims during the years 2013 and 2014, with a spatial analysis showing the number of incidents per 100 inhabitants. - Catalogue of economic activities which are susceptible of directly or indirectly producing noise, with geo-tagged registers indicating the type of activity (bar or restaurant, café, nightclub, etc.) - Study of public street use by bar and restaurant terraces in the centre of Malaga. - Social media and popular knowledge as sources of information about nightlife areas: walking zones, areas to drink in the street, etc. C. Method The method used for this research consists of the following stages: - Inventory of the existing noise sources. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 4
We identified all noise sources within the historic centre using acoustic parameters. However, due to their irregular and unpredictable nature, as well as a difficulty to measure, we purposely excluded noise sources coming from neighbour activities and occasional anti-social behaviours. - Acoustic characterization based on the source. We organized a noise measurement campaign in order to characterize the existing noise levels of every identified area and source. - Data processing of the noise monitoring system and results of the short measurements. We analysed the data provided by the noise monitoring system of the city council, identifying tendencies and assessing the behaviour of the existing noise levels, which we used as a basis to acoustically evaluate the sources based on the results of the short measurements and the correlation between them and their related station. - Noise affection measurement To determine the degree of affection, we defined a new global indicator of limit value exceedance, which we called Indicator of Global Affection (IGA). - Study of the designation of acoustically saturated zones (ASZ) and/or noise protection zones (NPZ). With the data gathered in this study, we proposed that the areas which do not meet the noise quality standards should be designated as special acoustic zones. Also, we defined their corresponding zonal plan for the specific area. 4. RESULTS A. Identifying and Characterizing the Acoustic Sources: Through the analysis of the existing information and the fieldwork done on the 202 streets that make up the study area, we have determined the noise sources not suitable for being modeled: - Terraces with or without enclosure. - Areas in the vicinity of bars and restaurants which, despite not having designated terraces, are likely to produce noise due to people talking outside while smoking and/or drinking. - Areas near nightclubs where the music is loud and which, despite not having a terrace, are likely to produce noise due to people talking outside while smoking and/or drinking as well as noise coming from inside the venue. - Crowds, especially when related to nightlife. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 5
Figure 3. 217 identified noise sources. Example of existing sources on a pedestrian walkway. According to the 217 identified sources, we designed a measurement campaign which included itinerant short-term measurements and monitoring stations with permanent data sampling: Figure 4. Location of the measurements. Yellow = short-term sampling. Blue = permanent sampling. B. Analysing the Collected Data Monitoring stations provide us with continuous equivalent levels that can be grouped by time period, e.g. 24-hour average evolution for each day of the week. If we compare the values gathered to the noise quality standards of the area, we find: - Failure to meet the standards during the three periods (morning, afternoon and night), except for the morning period from 9:00 to 13:00. - Generally, the noise level is very high. It rises sharply at weekends until it reaches maximum values of 80 db from 01:00h to 02:00h (25 dba above the limit values). - Minimum values exist from 05:00h to 07:00h, although still over the night-time limit values. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 6
Figure 5. 24-hour evolution for each day of the week and noise quality standards. While analysing the registers of the monitoring stations, we identified clear acoustic variation patterns during the different periods. These patterns depend on the location of the stations and the noise sources of the environment. Knowing how noise behaves depending on the characteristics of the environment allows us to predict the acoustic levels in any area by performing a temporary sampling of the noise within that area and determining the noise sources in that environment. For example, an identified tendency is typical of the areas where several terraces are found in one street. Figure 6. Noise tendency for a group of terraces. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 7
By knowing the location and sources of existing noises in each roaming measurement, it is possible to establish a noise evolution tendency that allows us to predict the equivalent levels for each period. This tendency will be determined by the evolution shown in the nearest monitoring station, provided that we consider it to have a similar evolution to that of the measurement. This station is known as a related station. C. Calculating the noise affection In order to determine the degree of affection of each point, we defined a new global indicator of limit value exceedance using the weight factor and penalties given by the Lden indicator. This Indicator of Global Affection (IGA) will be used to assign one of the defined affection categories to each zone. IGA = 10log ( 1 24 12(100.1(Ld 65) ) + 4(10 0.1(Le 65)+5 ) + 8(10 0.1(Ln 55)+10 )) (1) The degree of noise affection can be measured by applying the indicator to the stations and measurements: Table 2. Indicator of Affection. Measurement Monitoring Station Indicators Quality Nivel Lday Levening Lnight Lden Day Evening Night 98 60,94 63,26 59,84 66,95-4,06-1,74 4,84 10,30 105 73,26 74,11 79,68 85,24 8,26 9,11 24,68 29,94 106 68,93 69,78 75,35 80,91 3,93 4,78 20,35 25,61 108 64,47 67,71 66,35 72,76-0,53 2,71 11,35 16,71 Mlg - 5 61,90 63,00 70,60 76,10-3,10-2,00 15,60 20,84 Mlg - 6 66,70 71,70 68,70 75,40 1,70 6,70 13,70 19,10 Mlg - 9 63,70 66,90 64,60 71,20-1,30 1,90 9,60 15,00 IAG D. Study of the Designation of Acoustically Saturated Zones (ASZ) and/or Noise Protection Zones (NPZ) At this point, we have enough information to propose the delimitation boundaries of noise protection zones and acoustically saturated zones. More precisely, we have defined an acoustically saturated zone which includes 5 sub-zones, as shown in Fig. 7. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 8
Figure 7. Defined ASZ zone. Noise is one of the most important pollutants in our society today. Also, in Spain, 7% of nighttime noise annoyances are related to nightlife, coming in third as one of the most disturbing noise sources for that period (Spanish Sociological Research Centre, 2006). However, despite causing an increasing number of citizens' complaints, environmental noises coming from leisure activities are not included in the European initiatives regarding environmental noise management. We have devised a zonal action plan based on a state-of-the-art study of the actions that relieve the population from the annoyances caused by this type of source. This plan includes generic actions for the whole of the acoustically saturated zone as well as specific actions for every subzone according to the tendency of the noise and its degree of affection to the population. 5. CONCLUSIONS SNM results conclude that the city centre of Malaga is not a problematic area. However, the analysis of people's perception based on their complaints indicates that the historic centre is the most affected area (37% of 7,539 complaints). This situation requires a specific study identifying and quantifying the existing acoustic sources by measuring their emission values to allow us to assess whether noise levels comply with noise quality standards and, simultaneously, to determine the degree of affection to the population. The effects on the population amount to 3,790 affected residents, and night-time noise exposure exceeds the quality standards by up to 20 db. A zonal action plan is necessary. This plan must include action measures with goals, a schedule and a periodic assessment of the affection, the noise levels and the improvement in noise affection. Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 9
ACKNOWLEDGMENTS Environmental department of the Malaga City Council. REFERENCES [1] Directive 2002/49/EC of the European Parliament and Council, of 25 June 2002, relating to the assessment and management of environmental noise. «OJ» No. 189, of 18 July 2002, pages 12-25. Act 37/2003, of 17 November, relating to noise. «BOE» No. 276, 18 November 2003, pages 40494-40505. Royal Decree 1513/2005, of 16 December, relating to the development of Act 37/2003, of 17 November, relating to noise, environmental noise assessment and management. «BOE» No. 301, of 17 December 2005, pages 41356-41363. Royal Decree 1367/2007, of 19 October, relating to the development of Act 37/2003, of 17 November, relating to noise, noise zoning, quality standards and acoustic emissions. «BOE» No. 254, of 23 October 2007, pages 42952 42973 [2] Lopez Santos, Fernando et al, revisión y actualización de los planes de acción contra el ruido en Málaga, June 2015 [3] UTE Tecnitax Eygema revisión y actualización del mapa estratégico de ruido de la aglomeración de Málaga. Year 2013. [4] Medina-Montoya Hellgren, Luis et al, comparativa entre la percepción ciudadana de los conflictos acústicos y los conflictos determinados del análisis del mapa estratégico de ruido (MER) de la ciudad de Málaga, Valencia, Tecniacustica, October 2015 Proceedings of Meetings on Acoustics, Vol. 28, 040006 (2017) Page 10