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Abstract
As noise pollution is becoming more and more serious, many researchers are studying the noise attenuation effect provided by plants. This article examines six kinds of evergreens as research subjects so as to compare the different arrangements and densities of plants and their effect on noise attenuation. The authors studied the relationship between each of the plant's characteristics (the characteristics include leaf area, leaf fresh weight, leaf tactility, and leaf shape) and their average relative noise attenuation (deltaLAep). The authors then generated the noise-reducing spectrum of the six plants. The results show that there is a notable difference in noise-reducing effects for low frequency and high frequency (p < .05) when the plants are arranged differently. Also, every plant demonstrates a specific noise-reducing spectrum. By quantifying noise attenuation characteristics and abilities of plants, the authors combine noise attenuation species to achieve the mutual benefits of plant varieties and establish an ecotypic sound barrier model with effective density and arrangement.
... Environmental noise sources can be categorized as transportation, industry, construction, and entertainment and commercial noises resulting from human activities (Akça, 2009;Kurra, 2009). When evaluating noise sources, as seen in Table 1, the most impactful noise source on individuals in a residential area is traffic noise from highways (Fan et al., 2010;Paşaoğlu, 2013). When considering all types of noise sources, there are three main approaches to combat noise, aiming to reduce or prevent it: controlling noise at the source, controlling noise in the area between the source and the receiver (environment), and controlling noise in the receiver, the individual exposed to the noise (user) (Beranek, 1983;Şahin, 2003). ...
Today, environmental issues are rapidly increasing due to the growing population, rapid and unplanned urbanization, industrialization pressure, and advancing technology. Consequently, there is an accelerated search for solutions to environmental problems. As in the formation of these problems, humans will be a key factor in solving them. Therefore, individuals need to be developed and equipped in terms of environmental awareness, environmental consciousness, and environmental sensitivity. Many studies in the literature advocate the necessity of education to increase environmental awareness; however, first and foremost, individuals’ environmental awareness must be identified and their levels must be revealed. In this study, noise pollution, which has been increasingly impactful in the last 30 years and is ranked as the second-highest burden of disease by the World Health Organization after air pollution, with less awareness compared to other environmental issues, is evaluated. In this context, the research area is selected as the Çukurova District of Adana Province, and the awareness of noise pollution among the residents in the region is assessed through survey forms and SPSS software. Additionally, using the survey results, the proportional values of noise pollution as the most significant environmental issue are evaluated as spatial analysis and mapped.
... More than 40 per cent of the population in the European Union is exposed to traffic noise exceeding 55 dB(A) during the day and 20 per cent of the population is exposed to noise levels above 65 dB(A) (Fan et al., 2010;Onay, 2021). ...
The effect of artificial noise barriers (wall) on noise control varies according to the distance and height of the receiver. Therefore, the height of the wall should be increased to increase the coefficient of effect. In this case, while noise pollution is prevented, the cost of noise control increases, traffic safety decreases and visual quality of the city decreases as well as visual pollution. For these reasons, plant material should be used in noise control.
In the effective prevention of noise with the use of plant material, attention should be paid to the existence of the area required for noise screening, the establishment of noise screens and the species to be used. According to Ürgenç (1990), in order to reduce the noise caused by traffic in the city, the width of the noise screen formed by trees and shrubs should be 6-16 m, and the outer edge of this strip should be 5-16 m away from the centre of the nearest traffic line. In a study by Fang and Ling (2003), it was determined that a green belt (green corridor) of large shrubs reduces noise by more than 6 dB(A) at a distance of less than 5 m, a group of trees and shrubs reduces noise by 3-5.9 dB(A) at a distance of 6-19 m, and a group of sparse trees and shrubs reduces noise by less than 2.9 dB(A) at a distance of 20 m. In a study conducted in Ankara, Erdoğan and Yazgan (2007) found that a 3-row noise barriers provided a reduction of approximately 5 dB(A) in the amount of noise.
The main requirement for noise screening after the area width is the installation of noise screening. According to Çepel (1994), planting density is very important in noise reduction with plant materials. For example, he stated that the noise reduction degree of a dense tree community with a width of 30 m is equal to the noise reduction degree of a 140 m wide park consisting of sparse plants and trees. Therefore, according to Çepel (1994), in the establishment of the noise strip, starting from the direction of noise, shrubs should be used first, and inwards trees and short trees, and in the innermost part, tall leafy and coniferous tree species should be used. It is recommended that the leafy species to be used should be hard and broad-leaved and selected from evergreen species that do not shed their leaves in winter. In addition, other features sought in these trees are high stature, dense branch and leaf tissue up to the ground.
... Research indicates that increased leaf area and density enhance the noise reduction effect through leaf vibration (Aylor, 1972;Price et al., 1988). Additional factors such as leaf shape (Yang et al., 2010), branch structure (Cook and Van Haverbeke, 1971), leaf mass (Martens, 1980), and petiole characteristics ) also signi cantly impact noise reduction. Further investigations have shown that leaves exhibit varying effects on different sound frequencies, with notable differences in noise reduction capability for low-frequency versus high-frequency sounds Yang et al., 2013). ...
Street green spaces can effectively attenuate traffic noise, but the crucial role of coniferous trees and shrubs in the reduction of green space noise has not been systematically explored. Therefore, this study aimed to determine the mechanism of the influence of plant morphological characteristics and planting forms on the noise reduction effect using field measurements of the noise reduction effect of 36 street green spaces planted with coniferous trees and shrubs. It was found that for the same width of street green spaces, the noise reduction effects of planting single and multiple trees were significantly different, and this difference increased with an increase in street green space width. The noise reduction effect of planting low shrubs in street green spaces was significantly different from that of planting common shrubs in the same width, and their difference increased with an increase in street green space width. The factors that significantly affected the noise reduction effect of the 5 m–wide street green space were tree height, crown width, and DBH, and all of them were positively correlated. In addition, the noise reduction effect of the street green space planted with conifers was affected by the road and pavement widths. Finally, this study constructed a stepwise regression model for the noise reduction effect of street green spaces based on plant morphological parameters, planting methods, and physical characteristics of the road to quantify the crucial role of each factor in the noise reduction effect of street green spaces. The results of this study can provide plant noise reduction strategies for urban landscape planning and design to create a healthy urban acoustic environment.
... Huge vegetative area in and out of the forest is the reason for that comfort widely. Because vegetation reduces noise through reflecting, absorbing, scattering and refracting (Aylor, 1972;Fan et al., 2010;Fang and Ling, 2003;Ow and Ghosh, 2017). Shading by the vegetation cover restricts the excessive heating of the local environment by controlling the air temperature and provides shelter to the people from the direct thermal exposure (Doick and Hutchings, 2013;Emmanuel, 2005). ...
Bangladesh, as a developing country, is widely focused on its immense development projects without considering the environment and ecosystem. The natural ecosystem provides services to living organisms and contributes to maintaining a balance in the environmental equilibrium. In Bangladesh, Rema Kalenga Wildlife Sanctuary (RKWS) is the largest reserve forest after the Sundarbans, inhabiting a huge number of species, both floral and faunal. This study identifies the products and services (ecosystem services) that the RKWS generates to the population. A total of 212 provisioning services (fruit, fish, vegetables, medicine, flowers, crafts), a huge variety of ecosystem functions as regulating services, 84 cultural services (recreation and relaxation, spiritual and ritual practices, social relations, economic opportunities, academics and research, and different local beliefs), 150 plant species (46% tree, 22.66% shrub, 25.33% herb and 5.33% climber), 37 animal species (7 endangered and 3 vulnerable), 27 fish species (3 vulnerable) and 43 bird species (1 vulnerable and 1 critically endangered) has been identified at RKWS. The study provides an understanding of the huge importance of natural environment and ecosystem. Decision-makers and the government should look at it to consider the environment as an integral component of sustainable development. Also, further research and policy are required to manage not only the forests but also all the open green spaces in a way that is socially equitable and environmentally comprehensive.
... Urban green spaces with diverse vegetation mitigate urban heat island effects, regulate the local climate, and improve air quality by absorbing pollutants and producing oxygen (Gunawardena et al., 2017). They also act as noise buffers, benefiting densely populated areas by reducing the noise pollution (Yang et al., 2010). Madrid, Spain offers a successful example of urban forests and green corridors. ...
... Greenery in parks can play an essential role in reducing noise in the urban environment (Lacasta et al., 2016). First of all, parks are places where vegetation naturally occurs, including trees, shrubs, and grasses, which can act as natural noise barriers if planted sufficiently dense and compact (Yang et al., 2010). This vegetation can absorb sounds (Wong et al., 2010), reducing noise in and around parks. ...
In the contemporary world, where globalization and industrialization are progressing, there are no large cities that do not generate noise. Noise is usually connected with industrial areas, airports, circulation spaces or city centres. However, it is increasingly felt in places that have previously been associated with peace and quiet, such as suburban housing estates, recreational areas, urban forests, and parks. Noise penetrates public space, robbing this landscape of silence, pleasant sounds or positive sounds. The negative impact of noise on the life processes of humans and animals is worrying. Sound quality should be treated as an element of landscape quality, therefore it should be considered in planning processes or urban space development projects. The aim of this paper is to present an analysis of the soundscape in city space and of the level of noise in Centralny Park in Olsztyn, Poland. Guidelines were also drawn up for the proper management of park space in terms of reducing noise impact, and a model (recommendation) for analysed areas was formulated. The study consisted of:
– measurements of sound pressure levels (SPL) at selected points in two periods,
– interviews with park users and the preparation of a mental map,
– preparing a design scheme for a redesign of the park.
The results confirmed the difference between SPL in the leafless and leafy period. They also showed a clear relationship between the perception of sounds and well-being in the park.
... Nonetheless, these noise models still do not consider tree species or composition effects, such as the wider canopy and increased branches of spruce trees, which can reduce both noise and visibility. Several studies have demonstrated that vegetation can reduce noise levels and that certain species are better noise barriers than others (Kellomäki et al., 1976;Tekeyhah et al., 2019;Yang et al., 2010;Van Renterghem et al., 2021). Moreover, the density and structural arrangement of forests have been shown to be effective in reducing noise levels (Swearing and White, 2007). ...
Wind power is one of the fastest growing renewable energy sectors and plays a focal role in the transition to a fossil fuel free society in Europe. Technological developments have enabled the construction of turbines within forested areas, which has raised concerns regarding the audiovisual impact on these landscapes. However, there is a paucity of research with regard to the role that forests may play in mitigating the negative impacts of wind farms. In this study, we created a simplified model for noise attenuation based on the ISO 9613-2 and Nord2000 noise models and a visibility model which both relates the audiovisual effect to forest stand structure and applied them in the GIS environment. Our findings suggest that forests can act as effective noise barriers, with the sound attenuation level dependent on the distance that sound travels through the forest, as well as the size and density of the trees. However, in the case of a high elevation sound source (such as wind turbines), the forest begins to act as a noise shield from a distance of between 500 and 1500 m, depending on the height of the forest and the land topography. While current noise models do not consider the impact of tree species, our visibility model accounts for tree size, density and species, as well as understorey and thinning. Our results indicate that spruce trees provide a better visual constraint whereas visibility distances within mature Calluna-type pine forests tend to be more extensive. Both models include variables that can be adjusted by forest management, thereby allowing integration with forest planning software. Overall, this study presents indicative methods for the evaluation of potential forest landscape shields, a concept that could have broad applications, including Landscape Value Trading.
... Simpson (1998apud LOURENÇO et al., 2016 o esfriamento das temperaturas pode ocasionar uma economia significativa, devido à redução do uso de energia elétrica. • redução de ruídos: As árvores no meio urbano diminuem a poluição sonora, pois, segundo Yang (2010apud LOURENÇO et al., 2016 elas "têm sido associadas à atenuação de ruídos de diferentes frequências, agindo como barreiras verticais." Há estudos que mostram que, locais com maior incidência de áreas verdes tendem a reduzir em longo prazo, os incômodos gerados em locais de alta ou baixa intensidade de ruídos veiculares. ...
Este estudo objetiva discutir a importância das áreas verdes no espaço escolar, apresentando o papel educacional, ambiental e salutogênico desses ambientes. A escola, como um dos principais pilares da sociedade, tem papel fundamental nas mudanças de atitudes em relação às questões ambientais. Estas questões, por sua vez, devem ser trabalhadas de forma contextualizada, prática e significativa. Neste sentido, as áreas verdes possibilitam a quebra da rotina da aula tradicional em um espaço mais eclético, ideal para novos aprendizados e experiências. Em relação à saúde, as áreas verdes podem propiciar aos estudantes hábitos saudáveis, como a prática de exercícios e brincadeiras, que levam a redução da obesidade. Neste trabalho, a partir da revisão sobre o tema, evidenciamos a importância das áreas verdes em diferentes aspectos e apresentamos propostas práticas para a implantação e melhoria desses espaços nas escolas, sejam eles amplos ou restritos.
... A study by Ow and Ghosh (2017) showed that barriers formed by vegetation are very effective in reducing the noise produced on roads, reducing noise by more than 50% with its source. It is important to emphasize that the potential of sound barriers can vary according to the characteristics of the plant species used to form them (Fan et al., 2010). However, temporary artificial barriers produced with material obtained from plant pruning can be built (Gil-Lopez et al., 2017). ...
Abstract
Increasing population, developing technology, rapidly increasing cities and increasing environmental problems as a result of deteriorating natural balance by industrialization cause changes in the economic and social structure of societies. Accordingly, noise pollution, which is seen as one of the environmental problems, has serious negative effects on human health, life and comfort. Individuals and/or institutions that accept noise pollution as an important problem continue to work on detecting traffic noise and reducing noise pollution. Various methods are used in noise control studies. The most widely used of these are vegetative noise barriers. This study presents the results of the research on the use of plant material in noise prevention. In particular, many national and international studies have been examined in which the noise reduction abilities of plants are associated with the morphological characteristics of plant material and measurement methods for determining the noise reduction abilities of species are presented. This research is valuable in terms of revealing the results of these studies and comparing them with each other. The data and evaluations presented will shed light on the planning and design of noise barriers and especially on the selection of species, This will serve as a guide for practices aimed at reducing the effects of environmental problems such as noise pollution on people.
Keywords: Noise pollution, Noise control, Noise barrier, Plant material, Plant morphology.
In this paper, we demonstrate that it is possible to improve the sound attenuation obtained from a mass of trees by arranging them in a periodic lattice. The outdoor experimental results have shown that the largest sound attenuation, within a certain range of frequencies, was obtained for a range of frequencies related to the array periodicity. This behaviour induces us to believe that these arrays of trees work like sonic crystals. The sound attenuation values obtained in outdoor experiments for some periodic tree configurations, especially at low frequencies (f500Hz), were far higher than those obtained from a typical green belt or forest. Therefore, these periodic arrays could be used as green acoustic screens.
The biologic plausibility for noise stress-related cardiovascular responses is well established. Epidemiologic studies on the relationship between transportation noise and ischemic heart disease suggest a higher risk of myocardial infarction in subjects exposed to high levels of traffic noise.
To determine the risk of road traffic noise for the incidence of myocardial infarction (MI), we carried out a hospital-based case-control study in the city of Berlin. We enrolled consecutive patients (n=1881), age 20-69 years, with confirmed diagnosis of MI from 1998 through 2001. Controls (n=2234) were matched according to sex, age, and hospital. Outdoor traffic noise level was determined for each study subject based on noise maps of the city. Standardized interviews were conducted to assess possible confounding factors and the annoyance from various noise sources.
The adjusted odds ratio for men exposed to sound levels of more than 70 dB(A) during the day was 1.3 (95% confidence interval=0.88-1.8) compared with those where the sound level did not exceed 60 dBA. In the subsample of men who lived for at least 10 years at their present address, the odds ratio was 1.8 (1.0-3.2). Noise-exposed women were not at higher risk.
The results support the hypothesis that chronic exposure to high levels of traffic noise increases the risk for cardiovascular diseases.
It has been suggested that noise exposure increases the risk of hypertension. Road traffic is the dominant source of community noise exposure.
To study the association between exposure to residential road traffic noise and hypertension in an urban municipality.
The study population comprised randomly selected subjects aged 19-80 years. A postal questionnaire provided information on individual characteristics, including diagnosis of hypertension. The response rate was 77%, resulting in a study population of 667 subjects. The outdoor equivalent traffic noise level (Leq 24 h) at the residence of each individual was determined using noise-dispersion models and manual noise assessments. The individual noise exposure was classified in units of 5 dB(A), from <45 dB(A) to >65 dB(A).
The odds ratio (OR) for hypertension adjusted for age, smoking, occupational status and house type was 1.38 (95% confidence interval (CI) 1.06 to 1.80) per 5 dB(A) increase in noise exposure. The association seemed stronger among women (OR 1.71; 95% CI 1.17 to 2.50) and among those who had lived at the address for >10 years (OR 1.93; 95% CI 1.29 to 2.83). Analyses of categorical exposure variables suggested an exposure-response relationship. The strongest association between exposure to traffic noise and hypertension was found among those with the least expected misclassification of true individual exposure, as indicated by not having triple-glazed windows, living in an old house and having the bedroom window facing a street (OR 2.47; 95% CI 1.38 to 4.43).
The results of our study suggest an association between exposure to residential road traffic noise and hypertension.
Transmission of random noise through dense corn, a dense hemlock plantation, an open pine stand, dense hardwood brush, and over cultivated soil was measured. The relation between attenuation and frequency in these diverse cases suggested models that permit the prediction of attenuation in any configuration of vegetation and soil. The corn crop had an excess attenuation of 6 dB/100 ft for each doubling of frequency between 500 and 4000 Hz. On the other hand, the stems of the hemlock, pine, and brush all reduced noise by only about 5 dB/100 ft at 4000 Hz. Bare ground attenuates frequencies of 200–1000 Hz, and the frequency of maximum attenuation depends on the soil permeability to air. Thus, tilling the soil reduced the frequency of peak attenuation from 700 to 350 Hz and increased maximum attenuation at 52 m from the source by nearly 80%. Furthermore, earlier conflicting reports of noise attenuation by vegetation appear reconciled if ground attenuation is taken into account. Scattering and ground attenuation are the principal factors in sound attenuation by vegetation. Both factors attenuate relatively less sound as distance from the sound source increases. Hence measurements far from the source can underestimate the effect of a narrow band of vegetation or soil.
Many measurements of sound attenuation rates in forests have been made but there is little in common in the measuring procedures used or the results obtained. Consequently there is a considerable divergence of opinion on the effectiveness of vegetation as a noise control measure. In this paper the factors controlling the transmission of sound through vegetation are examined and the attenuation rates achieved in pine plantations are presented.
The propagation of sound through a large number of scatterers (i.e., trees) is treated in a similar way to a classical diffusion problem. A general differential equation governing the sound intensity is derived which is valid under certain conditions, notably that the depth of the belt of vegetation is large, and absorption small. The predictions of this theory are compared with results derived from a small scale model study, and with some field measurements. They are also compared with published field data. The implications of some of the conclusions reached for the practical achievement of effective sound attenuation are pointed out. In general, it would appear that significant noise reductions may be achieved for a predominantly high frequency source if the existing ground cover is acoustically hard, or if there is no ``ground effect'' attenuation between source and receiver for some other reason. In other cases, the noise reduction will be much lower and may be negative.
The effects of noise reduction of six tree belts were examined. An amplifier was placed in front of each tree belt, while a noise meter was placed at various heights and distances behind the tree belt. Net noise reduction effect termed as “relative attenuation” was obtained by subtracting the sound pressure level at each measurement site behind the tree belt from the sound pressure level at equal distances over open ground. Five parameters, including visibility, height, and width of the tree belt, height of receiver and noise source, and the distance between noise source and receiver, were studied. A multiple regression model demonstrating the order of importance of the five parameters in relation to relative attenuation was developed. The five parameters were then transformed into three-dimensionless parameters, i.e., h′: receiver and noise source height/tree height, d′: distance between noise source and receiver/tree height, and m′: belt width/visibility. By plotting the relative attenuation on the coordinate axis of h′, d′ and m′ and curve fitting, a three-dimensionless map of noise reduction by tree belts was formed. The map can be used as guidance in designing three belts for noise reduction in environmental planning.
Measurements were made at a number of sites of road traffic noise propagating through belts of trees and bushes and above grass-covered ground, respectively. The belt widths were between 3 and 25 m. The distance from the road to the front of the belts also varied from site to site. The microphones were placed 1·5 m above the ground. A comparison between attenuations obtained, expressed as differences in equivalent constant A-weighted sound pressure levels, LAeq, showed no significantly higher attenuation values for propagation through belts of trees than for propagation above grass-covered ground. Only in the frequency range above 2 kHz were attenuations significantly higher through the belts of trees and bushes. The belts of trees selected consisted mainly of deciduous trees and bushes between 5 and 10 years of age. Such types and widths are representative of what could often be used in normal urban situations in an attempt to provide practical noise reduction. According to the results of this investigation, however, these do not significantly reduce LAeq 1·5 m above the ground. Planting of belts of trees and bushes between roads and dwellings might influence the environmental quality of residential areas due to nonacoustic factors or reduce nuisance due to spectral changes not affecting LAeq. This has not been investigated.
This study investigates the noise reduction effect of 35 evergreen-tree belts. A point source of noise was positioned in front of the tree belts and the noise level at various points in the belts was measured with a noise meter. Factors important for noise reduction include visibility, width, height and length of the tree belts. Stepwise regression was employed to examine the factors associated with noise reduction. A negative logarithmic relationship between the visibility and relative attenuation was found. A positive logarithmic relationship between relative attenuation and the width, length or height of the tee belts was also found. A map showing the relationship between visibility together with width was plotted. The map provides some practical suggestions concerning design of tree belts for noise reduction.
The adverse effects of long-term exposure to a high volume of road traffic were studied in socio-acoustic surveys in 1997 and in 1999 after a substantial reduction in road traffic. The results obtained in 1997 showed a similar response pattern as in previously performed studies in the area in 1986 [Ohrström, J. Sound Vib. 122, 277-290 (1989)]. In 1999, road traffic had been reduced from 25000 to 2400 vehicles per day, and this resulted not only in a large decrease in annoyance and activity disturbances, but also in a better general well-being. The results suggest that a reduction in both noise and other pollutants from road traffic contribute to these effects. To be able to use the outdoor environment and to have the possibility to keep windows open is essential for general well-being and daily behavior, which implies that access both to quiet indoor and outdoor sections of the residency is of importance for achievement of a healthy sound environment. More knowledge of long-term health consequences of exposure to noise and simultaneous pollutants from road traffic is needed. Studies should focus more on "softer" health outcomes and well-being than hitherto and preferably be performed in connection with traffic abatement measures.