Sound propagation at micro‐scale in urban areas.

2011 ◽  
Vol 129 (4) ◽  
pp. 2364-2364 ◽  
Author(s):  
Jian Kang
1965 ◽  
Vol 37 (4) ◽  
pp. 738-747 ◽  
Author(s):  
Francis M. Wiener ◽  
Charles I. Malme ◽  
Creighton M. Gogos

1999 ◽  
Vol 60 (4) ◽  
pp. 4851-4859 ◽  
Author(s):  
J. Picaut ◽  
J. Hardy ◽  
L. Simon

2021 ◽  
Author(s):  
Sebastian Schlögl ◽  
Nico Bader ◽  
Julien Gérard Anet ◽  
Martin Frey ◽  
Curdin Spirig ◽  
...  

<p>Today, more than half of the world’s population lives in urban areas and the proportion is projected to increase further in the near future. The increased number of heatwaves worldwide caused by the anthropogenic climate change may lead to heat stress and significant economic and ecological damages. Therefore, the growth of urban areas in combination with climate change can increase future mortality rates in cities, given that cities are more vulnerable to heatwaves due to the greater heat storage capacity of artificial surfaces towards higher longwave radiation fluxes.</p><p>To detect urban heat islands and resolve the micro-scale air temperature field in an urban environment, a low-cost air temperature network, including 450 sensors, was installed in the Swiss cities of Zurich and Basel in 2019 and 2020. These air temperature data, complemented with further official measurement stations, force a statistical air temperature downscaling model for urban environments, which is used operationally to calculate hourly micro-scale air temperatures in 10 m horizontal resolution. In addition to air temperature measurements from the low-cost sensor network, the model is further forced by albedo, NDVI, and NDBI values generated from the polar-orbiting satellite Sentinel-2, land surface temperatures estimated from Landsat-8, and high-resolution digital surface and elevation models.</p><p>Urban heat islands (UHI) are processed averaging hourly air temperatures over an entire year for each grid point, and comparing this average to the overall average in rural areas. UHI effects can then be correlated to high-resolution local climate zone maps and other local factors.</p><p>Between 60-80 % of the urban area is modeled with an accuracy below 1 K for an hourly time step indicating that the approach may work well in different cities. However, the outcome may depend on the complexity of the cities. The model error decreases rapidly by increasing the number of spatially distributed sensor data used to train the model, from 0 to 70 sensors, and then plateaus with further increases. An accuracy below 1 K can be expected for more than 50 air temperature measurements within the investigated cities and the surrounding rural areas. </p><p>A strong statistical air temperature model coupled with atmospheric boundary layer models (e.g. PALM-4U, MUKLIMO, FITNAH) will aid to generate highly resolved urban heat island prediction maps that help decision-makers to identify local heat islands easier. This will ensure that financial resources will be invested as efficiently as possible in mitigation actions.</p>


2012 ◽  
Vol 111 (11) ◽  
pp. 114906 ◽  
Author(s):  
Miguel Molerón ◽  
Simon Félix ◽  
Vincent Pagneux ◽  
Olivier Richoux

1979 ◽  
Vol 21 (4) ◽  
pp. 523-550 ◽  
Author(s):  
Janice J. Monk ◽  
Charles S. Alexander

In geographic studies of modernization, attention has tended to focus on the processes of urbanization and the characteristics of urban areas rather than on rural areas. The latter have been included in macro-scale studies such as those of Gould and Soja in Africa investigating the spatial diffusion of modernization. In their studies of change in the Pacific, Brookfield (1973) and his associates also worked in rural communities, concentrating on the micro-scale. In research dealing with change in rural Latin America, emphasis has been on colonization studies and ruralurban migration, (Parsons, 1973; Preston, 1974; Stouse, 1971) but study of the effects of urbanization on change within a traditional rural areas has been neglected. Further, there have been few attempts in research on modernization to integrate macro and micro studies or to work at an intermediate scale.


Author(s):  
Axelle Degueurce ◽  
Patrick Dabert ◽  
Victor Argence ◽  
Laurent Blondel ◽  
Anne Le Bihan ◽  
...  

AbstractTo face the increase of waste production and meet the energy demand of urban areas, municipal waste management systems should be rethought. Innovative solutions such as decentralised small-scale anaerobic digestion could be developed. This work presents the design, operation and performances of a new micro-scale anaerobic digester (AD) developed to degrade food waste (FW) in urban areas i.e. highly compact and with low water and energy demand. To meet these objectives, the new micro-scale AD is a semi-continuous and two-stage process built vertically to take advantage of the gravity to mix and move the digested matter instead of using mechanical devices. The first stage consists in a tubular reactor fed weekly with FW and periodically watered with leachate from the second stage reactor located below the tubular reactor. Results show that AD performances were highly correlated to the efficiency of hydric transfer between the tubular reactor and the leachate tank. Indeed, pH, volatile fatty acids and microbial community analysis showed that the hydrolysis occurred in the tubular reactor, while the methanogenesis step occurred in the leachate tank. Overall, the average methane production was 143 ± 87 NL/kgvs with an average methane content of 44 ± 10% and the operation mode of the process has still to be improved. Graphic Abstract


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