Sep 7, 2007 - the Cuban standards in order to locate the most affected areas and propose some recommendations to mitigat
19th INTERNATIONAL CONGRESS ON ACOUSTICS MADRID, 2-7 SEPTEMBER 2007
URBAN NOISE IN HAVANA, SOME CONSIDERATIONS FOR ITS MITIGATION.
PACS: 43.50.Rq. Díaz, Gisela1; de la Peña Ana M.2, Castillo Maysel3 1 Faculty of Architecture of Havana, CUJAE, Cuba;
[email protected] 2 Faculty of Architecture of Havana, CUJAE, Cuba;
[email protected] 3 Faculty of Architecture of Havana, CUJAE, Cuba;
[email protected]
ABSTRACT This paper deals with urban noise studies carried out in main roads of Havana City. Data of traffic volume, type of transport, circulation speed, pedestrian flux, streets profile and surface material were collected as well as noise levels measured in selected streets. With this information was made a first-shot noise map of the central part of Havana and an evaluation of the Cuban standards in order to locate the most affected areas and propose some recommendations to mitigate the noise impact in the city.
INTRODUCCIÓN The first researches on urban noise in the City of Havana were carried out in 19831. They concluded that in the main roads prevailed noise levels (Leq) between 70 and 82 dBA. At the present time these studies have been restarted with the Cooperation of METRON and the UGZ of the Municipality of Zurich, in the frame of the Cuban-Swiss Project “Urban development and mobility in Havana: strategies for a sustainable integration”. The first results obtained in relation to the sound environment are briefly exposed below. It give a general vision of the territory, essential to produce a first-shot noise map, mitigation plans and proposals to transform some parts of the city. THE RESEARCH The study area The area selected for the first part of the study is the central part of the City of Havana, from the Bay (East), the Almendares River (West), the first ring of the Freeway (South) and the sea (North). (Figure 1) The street grid of this sector is practically the same since the last fifty years. Only some streets of the Historical Centre have been transformed for pedestrians or restricted only to cars circulation. A kind of not wanted mobility and new points of vehicle-vehicle and vehiclepedestrian conflict come out because of new functions that have been incorporated to the city, transformations in service equipments, road pavement deterioration, aged vehicles, between others. Scope of the study Besides the noise levels measurements in Leq, on each point was collected the traffic flow, type of transport, circulation speed, pedestrian flux, streets profile and material surface. The database was linked to other indicators such as air quality, obtained also as part of the research project.
Figure 1.- Havana selected study area.
Measurements procedures Main roads of 1st and 2nd order were selected within the study area. The measurement method corresponds with the described in the Cuban Standard 26:1999: Noise in urban areas. Hygienic requirements. 2 It was measured from 7 to 21 hours, at working days. The measurements and count up of vehicles were carried out during 15 minutes, each hour, for each point. The equivalent sound level was determined (Leq), with an A filter and fast response. The microphone position was 1,50 m height from the floor level with an orientation of its axis perpendicular to the axis of the road. More than 1, 00 m of separation from any vertical surface that could distort the measurements. Simultaneously, the volume and type of traffic were registered (heavy, cars, motorcycles and bikes). Any other existent source of noise was identified according to the observer's perception in each point. Two Integrated precision sound level meters Brüel & Kjaer were used: One Type 2230 Class I and the other Type 2221 Class I. Calibration was made with a BK-4220. THE RESULTS With the collected data was elaborated a noise map (Figure 2) and a traffic volume map (Figure 3). In them can be observed that the prevailing noise levels are between 75 and 80 dBA which corresponds with roads of high and very high traffic for Cuban conditions; consequently, those with levels between 70 and 75 dBA, have a correspondence with medium traffic volumes. With this observation also a contradiction appears and a deeper analysis turns a necessity. For example, Malecon(1) with high traffic has the same noise levels as others roads of the central part of the city with not so high traffic(2). It is evident that the morphology of the urban area has an important influence, as well as the quality of pavements, the heavy transport and pedestrian circulation. Havana is mainly a pedestrian city, and this characterizes its sound environment. For example, at the Historical Centre(3), tourism together with the residents and workers everyday activities generates equivalents noise levels between 65 and 75 dBA, with some specific musical events that raises this levels up to 95 dBA. Cuban standard 26:1999: Noise in urban areas. Hygienic requirements, establishes limits of 68 dBA in the day period and 58 dBA at night when traffic is the main noise source. It is obvious that most of the city transgress this values, even in the commercial areas where the limits are higher, being accepted up to 75 dBA and 71 dBA, day and night, respectively. The NC 435:2006 Acoustic requirements for buildings3, is even more restricted establishing a limit of 60 dBA. Preliminaries studies of air quality (NO2) related to noise levels and traffic volumes have been made in Havana4. Figure 4 shows the results which demonstrate that vehicular traffic is not always the main pollution source. Wind has a great influence and this is evident in the sea border where NO2 is low instead of the high traffic. The same situation appears in Rancho Boyeros, located in an open suburban area. In the central areas the concentration of this contaminant is higher as well as the noise. 2 19th INTERNATIONAL CONGRESS ON ACOUSTICS – ICA2007MADRID
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Figure 2.- Noise level map (Leq)
Figure 3.- Traffic volume map
Veh/dia (miles)
Heavy trafic (%)
PLAN
Rancho Boyeros y Camaguey
Ly Calzada
Virgen del Camino NO2
23 y 42
20 18 16 14 12 10 8 6 4 2 0 10 de Octubre
50 45 40 35 30 25 20 15 10 5 0 Egido
Number of vehicles
Traffic volume vs NO2
VIEW
Veh pesados/dia
Figure 4 - Air pollution related to traffic volume.
Figure 5- Proposal for a Centro Habana street: with restricted access.
CONCLUSIONS We can conclude that in the City of Havana a great part of its territory do not have healthy environment due to noise pollution. This territory mainly corresponds to the central and dense zones, but do not have a great difference with the rest of the city with respect to noise levels (Leq). It can be said that there are three main situations related to noise pollution in Havana: 1. Produced mainly by community activities, with low volumes of vehicles and medium to high pedestrian circulation. 2. Produced by the two sources: high or very high volume of vehicle, high pedestrian mobility. 3. Produced mainly by traffic noise with high or very high volume of vehicle and low pedestrian circulation. Each of these situations should have a different mitigation strategy. For the first case, a deeper study is needed in order to characterize the local noise sources and specific noise control solutions. New integrated planning at local level is important as well as the environmental education of the community. For the second and third cases noise abatement should be based in traffic volume and velocities reduction strategies 5 At the city level a redistribution of the commercial activities and other services is also necessary. 3 19th INTERNATIONAL CONGRESS ON ACOUSTICS – ICA2007MADRID
References: [1] A. Ambou. Primer nomograma acústico para las construcciones en Cuba.Investigación Construcción. MICONS. Cuba (1983). [2] Cuban Standard 26:1999: Noise in urban areas. Hygienic requirements.
[3] Cuban Standard 435:2006 Acoustic requirements for buildings, [4] CENIC – UGZ Zurich. Evaluación de la concentración de NO2 en Ciudad de La Habana. Informe de investigación. La Habana, Cuba (2007). [5] L. Martín. Propuesta para “calmar el tráfico” en Centro Habana. Trabajo de Curso. Facultad de Arquitectura.(2007)
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