| 1. |
- Andersson-Sköld, Yvonne, et al.
(författare)
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A framework for assessing urban greenery's effects and valuing its ecosystem services
- 2018
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Ingår i: Journal of Environmental Management. - : Academic Press. - 0301-4797 .- 1095-8630. ; 205, s. 274-285
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Tidskriftsartikel (refereegranskat)abstract
- Ongoing urban exploitation is increasing pressure to transform urban green spaces, while there is increasing awareness that greenery provides a range of important benefits to city residents. In efforts to help resolve associated problems we have developed a framework for integrated assessments of ecosystem service (ES) benefits and values provided by urban greenery, based on the ecosystem service cascade model. The aim is to provide a method for assessing the contribution to, and valuing, multiple ES provided by urban greenery that can be readily applied in routine planning processes. The framework is unique as it recognizes that an urban greenery comprises several components and functions that can contribute to multiple ecosystem services in one or more ways via different functional traits (e.g. foliage characteristics) for which readily measured indicators have been identified. The framework consists of five steps including compilation of an inventory of indicator; application of effectivity factors to rate indicators' effectiveness; estimation of effects; estimation of benefits for each ES; estimation of the total ES value of the ecosystem. The framework was applied to assess ecosystem services provided by trees, shrubs, herbs, birds, and bees, in green areas spanning an urban gradient in Gothenburg, Sweden. Estimates of perceived values of ecosystem services were obtained from interviews with the public and workshop activities with civil servants. The framework is systematic and transparent at all stages and appears to have potential utility in the existing spatial planning processes.
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| 2. |
- Thorsson, Pontus, 1974, et al.
(författare)
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Vibrationsdämpande markfilter för reduktion av markvibrationer vid sprängning i bergtäkter
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet som presenteras i denna rapport har studerat möjligheterna att dämpa markvibrationer från sprängningar med hjälp av luftfyllda hål i berg. Principen är att förändringen i materialparametrar mellan berget och luften i hålen skapar reflektion av vibrationerna. Teoretisk och praktisk litteratur visar på möjligheten att skapa destruktiv interferens mellan de olika reflexerna som kan styras till att dämpa markvibrationerna. Detta projekt har utfört praktiska fältförsök i full skala för att utreda om tekniken är möjlig att använda kring bergtäkter.De utförda provningarna i verkliga miljöer visar på att det finns möjligheter att dämpa markvibrationer genom att skapa ett metamaterial som består av borrade hål i berg. Störst effekt får man om man kan skapa tillräckligt stora hål jämfört med vibrationens våglängd. Genom att välja rätt geometri, d v s håldiameter och borrplan, kan man välja vilka frekvenser där vibrationen ska reduceras.I de praktiska försöken som genomförts i detta projekt har det visats att man kan simulera stora hål genom att borra mindre hål tätt samman inom en cirkel. Detta är ett mycket viktigt resultat då de relevanta våglängder i bergtäktsammanhang är långa, vilket kräver stora håldiametrar. De simulerade stora hålen i Glimmingen visade på en potentiell dämpning av vertikala vibrationshastigheter med omkring 50 % i frekvensbanden 100-125 Hz. Detta är stora sänkningar som bör undersökas vidare om de kan realiseras praktiskt vid befintlig bergtäkt. Vid bostäder som ligger nära bergtäkter är det vanligt att vibrationshastigheterna har högst värden vid ca 30 – 40 Hz, vilket medför att de simulerade hålen skall vara 2 – 3 gånger större än de som borrades i Glimmingen. Detta medför grupperingar av borrhål inom cirklar som är omkring 3 m i diameter.Vidare visade de praktiska försöken att effektiviteten av ett sådant filter måste utvärderas med mätningar i samma punkter före och efter ett filter har konstruerats. Annars finns risk att man attribuerar vågdämpnings- och eventuella vågförstärkningseffekter som sker i berget till filtret. Kort sagt, filtrets effektivitet utvärderas felaktigt.Innan metoden med markfilter av borrhål kan användas som ett praktiskt hjälpmedel att minska markvibrationer kring bergtäkter måste ett designverktyg skapas som kan hantera alla platsspecifika variabler.
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| 3. |
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| 4. |
- Ageborg Morsing, Julia, et al.
(författare)
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Wind Turbine Noise and Sleep: Pilot Studies on the Influence of Noise Characteristics
- 2018
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 15:11
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Tidskriftsartikel (refereegranskat)abstract
- The number of onshore wind turbines in Europe has greatly increased over recent years, a trend which can be expected to continue. However, the effects of wind turbine noise on long-term health outcomes for residents living near wind farms is largely unknown, although sleep disturbance may be a cause for particular concern. Presented here are two pilot studies with the aim of examining the acoustical properties of wind turbine noise that might be of special relevance regarding effects on sleep. In both pilots, six participants spent five consecutive nights in a sound environment laboratory. During three of the nights, participants were exposed to wind turbine noise with variations in sound pressure level, amplitude modulation strength and frequency, spectral content, turbine rotational frequency and beating behaviour. The impact of noise on sleep was measured using polysomnography and questionnaires. During nights with wind turbine noise there was more frequent awakening, less deep sleep, less continuous N2 sleep and increased subjective disturbance compared to control nights. The findings indicated that amplitude modulation strength, spectral frequency and the presence of strong beats might be of particular importance for adverse sleep effects. The findings will be used in the development of experimental exposures for use in future, larger studies.
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| 5. |
- Forssén, Jens, 1968, et al.
(författare)
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Road traffic noise propagation to an inner yard – Measurements before and after the construction of gap filling buildings
- 2009
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Ingår i: 8th European Conference on Noise Control 2009, EURONOISE 2009; Edinburgh; United Kingdom; 26 October 2009 through 28 October 2009. - 9781615676804 ; 31:PART 3, s. 7-
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Konferensbidrag (refereegranskat)abstract
- The propagation of noise to inner yards is a subject of large interest, for instance due to new formulations of noise limits. The presented measurements were made within a larger research programme, in one of its application examples, for which also a perceptual study is ongoing. Here, the propagation of noise from the motorway nearby is investigated using acoustic measurements from both before and after gap filling buildings were constructed. As result of the construction, gaps between a row of housing buildings were sealed by additional housing units thus forming a continuous, tall and thick barrier along the motorway. It is shown that the row of separate buildings with gaps in-between, in the before-study, provided minor shielding of the yard behind, whereas, in the after-study, significantly lower noise levels were found. The reduction due to the gap filling buildings is estimated to reach 8-9 dB at most.
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| 6. |
- Hagberg, K., et al.
(författare)
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Uncertainties in standard impact sound measurement and evaluation procedure applied to light weight structures
- 2010
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Ingår i: 20th International Congress on Acoustics 2010, ICA 2010 - Incorporating Proceedings of the 2010 Annual Conference of the Australian Acoustical Society. - 9781617827457 ; 4, s. 2646-2652
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Konferensbidrag (refereegranskat)abstract
- A three year research programme has recently started in Sweden, aiming at improving the mutual connection between the perceived sound, vibration and springiness and their corresponding measured values in lightweight structures. The main goal is to describe new objective measures of assessing the acoustic quality, with the expected result that the experienced sound, vibration and springiness are not dependent of structural bearing system in the building any more. The consequence of new methods will be that various structural systems within one certain sound class in a classification scheme will provide fairly equal evaluation with regard to subjective response. The research programme, Aku- Lite, is divided into seven work packages (WP). Initial results from one work package (WP 4), related to current subjective and objective field data are presented in this paper. The aim of topical part of the study is to investigate the liability of measurements results and evaluation procedure when those are carried out in accordance to ISO 140 and ISO 717. It involves an initial inventory and analysis from objective measurements, according to ISO 140, performed on light weight structures on the field by various consultants in Sweden. The study considers principal problems with current standards, affecting each operator performing field measurements in light weight structures and thereby impacting the final result quality. Typically, the measured sound pressure level and the reverberation time differ a lot in low frequencies, compared to heavy structures. The measurement result (distribution) between various measurement positions is rather random in the low frequency region, i.e. there is no typical pattern for light weight structures in general. The complexity of different light weight structural bearing systems and their sensitivity in the low frequency range requires a more rigid description of the measurement and evaluation procedure. The lack of objective sound and vibration data below 50 Hz is also a problem since subjective disturbance often emanates from this frequency range. Copyright
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| 7. |
- Hedblom, Marcus, et al.
(författare)
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Reduction of physiological stress by urban green space in a multisensory virtual experiment
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Although stress is an increasing global health problem in cities, urban green spaces can provide health benefits. There is, however, a lack of understanding of the link between physiological mechanisms and qualities of urban green spaces. Here, we compare the effects of visual stimuli (360 degree virtual photos of an urban environment, forest, and park) to the effects of congruent olfactory stimuli (nature and city odours) and auditory stimuli (bird songs and noise) on physiological stress recovery. Participants (N = 154) were pseudo-randomised into participating in one of the three environments and subsequently exposed to stress (operationalised by skin conductance levels). The park and forest, but not the urban area, provided significant stress reduction. High pleasantness ratings of the environment were linked to low physiological stress responses for olfactory and to some extent for auditory, but not for visual stimuli. This result indicates that olfactory stimuli may be better at facilitating stress reduction than visual stimuli. Currently, urban planners prioritise visual stimuli when planning open green spaces, but urban planners should also consider multisensory qualities.
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| 8. |
- Hedblom, Marcus, et al.
(författare)
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Sounds of Nature in the City: No Evidence of Bird Song Improving Stress Recovery
- 2019
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1660-4601 .- 1661-7827. ; 16:8
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Tidskriftsartikel (refereegranskat)abstract
- Noise from city traffic is one of the most significant environmental stressors. Natural soundscapes, such as bird songs, have been suggested to potentially mitigate or mask noise. All previous studies on masking noise use self-evaluation data rather than physiological data. In this study, while respondents (n = 117) watched a 360 degrees virtual reality (VR) photograph of a park, they were exposed to different soundscapes and mild electrical shocks. The soundscapesbird song, bird song and traffic noise, and traffic noisewere played during a 10 min recovery period while their skin conductance levels were assessed as a measure of arousal/stress. No significant difference in stress recovery was found between the soundscapes although a tendency for less stress in bird song and more stress in traffic noise was noted. All three soundscapes, however, significantly reduced stress. This result could be attributed to the stress-reducing effect of the visual VR environment, to the noise levels being higher than 47 dBA (a level known to make masking ineffective), or to the respondents finding bird songs stressful. Reduction of stress in cities using masking with natural sounds requires further studies with not only larger samples but also sufficient methods to detect potential sex differences.
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| 9. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Influence of urban vegetation on air pollution and noise exposure – A case study in Gothenburg, Sweden
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 599-600, s. 1728-1739
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution levels (NO2, PAHs, O3) were investigated, before (BLE) and after (ALE) leaf emergence, in the urban landscape of Gothenburg, Sweden. The aims were to study the 1) spatial and temporal variation in pollution levels between urban green areas, 2) effect of urban vegetation on air pollution levels at the same distance from a major emission source (traffic route), 3) improvement of urban air quality in urban parks compared to adjacent sites near traffic, 4) correlation between air pollution and noise in a park. O3 varied little over the urban landscape. NO2 varied strongly and was higher in situations strongly influenced by traffic. Four PAH variables were included: total PAH, total particle-bound PAH, the quantitatively important gaseous phenanthrene and the highly toxic particle-bound benzo(a)pyrene. The variation of PAHs was similar to NO2, but for certain PAHs the difference between highly and less polluted sites was larger than for NO2. At a vegetated site, NO2 and particulate PAH levels were lower than at a non-vegetated site at a certain distance from a busy traffic route. This effect was significantly larger ALE compared to BLE for NO2, indicating green leaf area to be highly significant factor for air quality improvement. For particulate PAHs, the effect was similar BLE and ALE, indicating that tree bark and branches also could be an important factor in reducing air pollution. Parks represented considerably cleaner local environments (park effect), which is likely to be a consequence of both a dilution (distance effect) and deposition. Noise and air pollution (NO2 and PAH) levels were strongly correlated. Comparison of noise levels BLE and ALE also showed that the presence of leaves significantly reduced noise levels. Our results are evidence that urban green spaces are beneficial for urban environmental quality, which is important to consider in urban planning.
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| 10. |
- Kropp, Wolfgang, 1959, et al.
(författare)
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BUILDING ACOUSTICS AND THE “MILLION PROGRAMME” IN SWEDEN
- 2023
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Ingår i: Proceedings of Forum Acusticum. - 2221-3767.
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Konferensbidrag (refereegranskat)abstract
- The paper focus on the development of building acoustics in Sweden exemplified by the activities at Chalmers University of Technology. Developments are often initiated by incidences where people meet at a place in a certain context. So also happened in Sweden in the middle of the forties when Per Bruel came as refugee from the German occupied Denmark to Chalmers where he started the Chalmers Acoustic Laboratory. He was soon joined by Uno Ingård who later was professor at MIT. At that time Sweden was in a transformation process from an agrarian to a highly industrialized nation leading to a large urbanization. Shortage of housing and the need to increase housing standard led to the so-called million programme with the goal to build one million flats. New building technologies (e.g., light concrete walls or the use of prefabricated elements) as well as the need/wish for cost efficiency led however to buildings of varying quality with new challenges with respect to building acoustics. As consequence building acoustics was identified as important part in the education of civil engineers and in 1962 Chalmers established a professorship in building acoustics. In 1969 Tor Kihlman became the first professor in building acoustics in Sweden.
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