scholarly journals Using Climate-Sensitive 3D City Modeling to Analyze Outdoor Thermal Comfort in Urban Areas

2020 ◽  
Vol 9 (11) ◽  
pp. 688
Author(s):  
SeyedehRabeeh HosseiniHaghighi ◽  
Fatemeh Izadi ◽  
Rushikesh Padsala ◽  
Ursula Eicker

With increasing urbanization, climate change poses an unprecedented threat, and climate-sensitive urban management is highly demanded. Mitigating climate change undoubtedly requires smarter urban design tools and techniques than ever before. With the continuous evolution of geospatial technologies and an added benefit of analyzing and virtually visualizing our world in three dimensions, the focus is now shifting from a traditional 2D to a more complicated 3D spatial design and assessment with increasing potential of supporting climate-responsive urban decisions. This paper focuses on using 3D city models to calculate the mean radiant temperature (Tmrt) as an outdoor thermal comfort indicator in terms of assessing the spatiotemporal distribution of heat stress on the district scale. The analysis is done to evaluate planning scenarios for a district transformation in Montreal/Canada. The research identifies a systematic workflow to assess and upgrade the outdoor thermal comfort using the contribution of ArcGIS CityEngine for 3D city modeling and the open-source model of solar longwave environmental irradiance geometry (SOLWEIG) as the climate assessment model. A statistically downscaled weather profile for the warmest year predicted before 2050 (2047) is used for climate data. The outcome shows the workflow capacity for the structured recognition of area under heat stress alongside supporting the efficient intervention, the tree placement as a passive strategy of heat mitigation. The adaptability of workflow with the various urban scale makes it an effective response to the technical challenges of urban designers for decision-making and action planning. However, the discovered technical issues in data conversion and wall surface albedo processing call for the climate assessment model improvement as future demand.

2020 ◽  
Vol 158 ◽  
pp. 01002
Author(s):  
Yuqiao Huang ◽  
Dayi Lai ◽  
Yiqing Liu ◽  
Huang Xuan

Since urban open spaces provide various benefits to the citizens, it is necessary to improve the outdoor thermal comfort in urban open spaces. However, global warming increases heat stress and at the same time decrease cold stress of outdoor spaces. The final impact of climate change on outdoor thermal comfort is not evident, and depends on the climate characteristics. This study investigated the influence of climate change on outdoor thermal comfort conditions of five selected cities (Minneapolis, New York City, San Francisco, Miami, and Las Vegas) with distinctive climate patterns in the United States. It is found that all cities suffered from deterioration in thermal comfort. This is because the increases in the heat stress rate were greater than the decreases in cold stress rate. In the 2080s, the greatest reduction in acceptable thermal stress rate happened in Miami from 44.7% to 21.3% under high emission scenario.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4730
Author(s):  
Mohamed Elhadi Matallah ◽  
Waqas Ahmed Mahar ◽  
Mushk Bughio ◽  
Djamel Alkama ◽  
Atef Ahriz ◽  
...  

Climate change and expected weather patterns in the long-term threaten the livelihood inside oases settlements in arid lands, particularly under the recurring heat waves during the harsh months. This paper investigates the impact of climate change on the outdoor thermal comfort within a multifamily housing neighborhood that is considered the most common residential archetype in Algerian Sahara, under extreme weather conditions in the summer season, in the long-term. It focuses on assessing the outdoor thermal comfort in the long-term, based on the Perceived Temperature index (PT), using simulation software ENVI-met and calculation model RayMan. Three different stations in situ were conducted and combined with TMY weather datasets for 2020 and the IPCC future projections: A1B, A2, B1 for 2050, and 2080. The results are performed from two different perspectives: to investigate how heat stress evolution undergoes climate change from 2020 till 2080; and for the development of a mathematical algorithm to predict the outdoor thermal comfort values in short-term, medium-term and long-term durations. The results indicate a gradual increase in PT index values, starting from 2020 and progressively elevated to 2080 during the summer season, which refers to an extreme thermal heat-stress level with differences in PT index averages between 2020 and 2050 (+5.9 °C), and 2080 (+7.7 °C), meaning no comfortable thermal stress zone expected during 2080. This study gives urban climate researchers, architects, designers and urban planners several insights into predicted climate circumstances and their impacts on outdoor thermal comfort for the long-term under extreme weather conditions, in order to take preventive measures for the cities’ planning in the arid regions.


Climate ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Dirk Lauwaet ◽  
Bino Maiheu ◽  
Koen De Ridder ◽  
Wesley Boënne ◽  
Hans Hooyberghs ◽  
...  

In urban areas, high air temperatures and heat stress levels greatly affect human thermal comfort and public health, with climate change further increasing the mortality risks. This study presents a high resolution (100 m) modelling method, including detailed offline radiation calculations, that is able to efficiently calculate outdoor heat stress for entire urban agglomerations for a time period spanning several months. A dedicated measurement campaign was set up to evaluate model performance, yielding satisfactory results. As an example, the modelling tool was used to assess the effectiveness of green areas and water surfaces to cool air temperatures and wet bulb globe temperatures during a typical hot day in the city of Ghent (Belgium), since the use of vegetation and water bodies are shown to be promising in mitigating the adverse effects of urban heat islands and improving thermal comfort. The results show that air temperature reduction is most profound over water surfaces during the afternoon, while open rural areas are coolest during the night. Radiation shading from trees, and to a lesser extent, from buildings, is found to be most effective in reducing wet bulb globe temperatures and improving thermal comfort during the warmest moments of the day.


Biomimetics ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 48
Author(s):  
Kevin Araque ◽  
Paola Palacios ◽  
Dafni Mora ◽  
Miguel Chen Austin

In recent years, demographic growth has caused cities to expand their urban areas, increasing the risk of overheating, creating insurmountable microclimatic conditions within the urban area, which is why studies have been carried out on the urban heat island effect (UHI) and its mitigation. Therefore, this research aims to evaluate the cooling potential in the application of strategies based on biomimicry for the microclimate in a historical heritage city of Panama. For this, three case studies (base case, case 1, and case 2) of outdoor thermal comfort were evaluated, in which the Envi-met software was used to emulate and evaluate the thermal performance of these strategies during March (highest temperature month) and October (rainier month). The strategies used were extracted from the contrast of zebra skin, human skin, evaporative cooling, and ant skin. The results showed a reduction of 2.8 °C in the air temperature at 11:00, the radiant temperature decreased by 2.2 °C, and the PET index managed to reduce the thermal comfort indicator among its categories. The importance of thinking based on biomimicry in sustainable strategies is concluded; although significant changes were obtained, high risks of discomfort persist due to the layout and proximity of the building.


2021 ◽  
Author(s):  
Barry O'Dwyer ◽  
Roberta Paranunzio ◽  
Edward Dwyer

<p>Ireland’s climate is changing and these changes are projected to intensify into the future posing an increasing risk to Ireland’s environment, society and economy. For Ireland and its urban areas in particular, projected changes in the frequency and intensity of heatwaves is considered a moderate but real risk. For example, it is considered likely that Ireland’s capital city Dublin will experience increases in the frequency and intensity of heatwaves under projected climate change. Moreover Ireland’s population is ageing faster than other parts of Europe and becoming increasingly vulnerable to heat stress.</p><p>To date, little attention has focussed on heat-related risks for Ireland’s urban areas, focussing primarily on risks associated with sea level rise and changing patterns of precipitation. Through this work, we provide an innovative approach that allows for the integrated assessment of current and future heat risk for the Greater Dublin Area.  Employing a range of modelling approaches, landcover projections have been developed and future changes in urban heat projected, and spatiotemporal variations in level of exposure to heat stress have been calculated using the Universal Thermal Climate Index (UTCI) for current and future periods (2020s – 2050s) under a range of radiative forcing scenarios (RCP4.5 and 8.5).  These assessments are combined with vulnerability information (socio-economic data) to obtain spatially-explicit indexes of heat risk and for different scenarios (RCPs). As a result of projected changes in landcover and temperatures, our assessments show that the level of exposure to extreme heat stress will increase in the coming decades and this is particularly the case for the RCP 8.5 scenario. In combination with assessments of vulnerability, this study identifies significant spatial clusters in the denser urban core of the city and peri-urban areas that are considered to be at relatively high levels of heat risk.</p><p>Spatial planning and land use planning are emerging as policy areas that can have significant influence on adaptation to and mitigation of climate change. Through spatial planning, the ways in which cities are designed in order to minimise risks can be re-evaluated and the complexity and uncertainty of climate change tackled.  This study provides spatially explicit information at a fine scale on the evolution of exposure and vulnerability related to thermal heat stress that will support stakeholders to implement strategies and policies aimed at mitigating and adapting to ongoing and future urban heat risk.  </p><div> </div>


2020 ◽  
Vol 12 (10) ◽  
pp. 4082 ◽  
Author(s):  
Tom Assmann ◽  
Sebastian Lang ◽  
Florian Müller ◽  
Michael Schenk

Mitigating climate change and improving urban livability is prompting cities to improve sustainability of urban transportation and logistics. Cargo bikes, in combination with urban transshipment points, are gaining momentum as a green last mile alternative. Although a wide body of research proves their viability in dense urban areas, knowledge about planning urban transshipment points is very limited. This also entails the siting of such facilities and the assessment of effects on emissions. This study therefore presents a first quantitative scenario-based model that assesses the impacts on a district. It examines different strategies for siting urban transshipment points in a single district and its effect on traffic, the carbon footprint, and air quality to give strategic insights where to create candidate locations for such facilities. Our result contributes to knowledge of planning urban transshipment facilities and assessing the impact of different configurations. The findings demonstrated that the use of cargo bikes to make courier, express, and parcel (CEP) deliveries in urban districts could reduce greenhouse gas (GHG), particulate matter (PM10), and nitrogen oxides (NOx) emissions significantly. However, the choice of vehicles completing inbound and outbound processes and the strategies for siting urban transshipment points display widely differing and even conflicting potential to reduce emissions.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hanna Leona Lokys ◽  
Jürgen Junk ◽  
Andreas Krein

Projected climate change will cause increasing air temperatures affecting human thermal comfort. In the highly populated areas of Western-Central Europe a large population will be exposed to these changes. In particular Luxembourg—with its dense population and the large cross-border commuter flows—is vulnerable to changing thermal stress. Based on climate change projections we assessed the impact of climate change on human thermal comfort over the next century using two common human-biometeorological indices, the Physiological Equivalent Temperature and the Universal Thermal Climate Index. To account for uncertainties, we used a multimodel ensemble of 12 transient simulations (1971–2098) with a spatial resolution of 25 km. In addition, the regional differences were analysed by a single regional climate model run with a spatial resolution of 1.3 km. For the future, trends in air temperature, vapour pressure, and both human-biometeorological indices could be determined. Cold stress levels will decrease significantly in the near future up to 2050, while the increase in heat stress turns statistically significant in the far future up to 2100. This results in a temporarily reduced overall thermal stress level but further increasing air temperatures will shift the thermal comfort towards heat stress.


2014 ◽  
Vol 2 (2) ◽  
pp. 25-36 ◽  
Author(s):  
Modeste Kameni Nematchoua ◽  
Gholamreza Roshan ◽  
René Tchinda ◽  
◽  
◽  
...  

2021 ◽  
Vol 30 (3) ◽  
pp. 95-107
Author(s):  
Anna Haładyj ◽  
Katarzyna Kułak-Krzysiak

The aim of the article was to explore pet welfare in Municipal Adaptation Plans (MAPs), based on a literature review and case studies of 40 MAPs accepted in Poland as part of the “Let’s Feel the Climate” project, supported by the Polish Ministry of Environment in 2017–2019. The study summarizes the concept of climate change and the importance of adaptation measures with particular emphasis on urban heat islands and heat stress, acknowledged by climate change literature, and outlines pet welfare in the context of thermal comfort and threats caused by heat stress. Because the authors subsequently presented an empirical study of the 40 accepted MAPs, they also discussed the role and legal nature of MAPs. The main hypothesis of this survey of Polish MAPs was that pet welfare in the context of their thermal comfort is an example of the adaptive measures clearly stipulated in Polish MAPs, which was examined after presenting the MAPs’ findings. The starting point was the assumption that the welfare of pets should also be assessed from the perspective of their thermal comfort – a new element of broadly understood animal welfare. This is due to the fact that pets are exposed to the risk of heat stress resulting from urban heat islands and, just like people, have to endure the inconvenience of extreme weather phenomena, which is impossible without the support of amenities such as drinkers or water shelters and the development of green and blue infrastructure.


Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1013
Author(s):  
Max Anjos ◽  
António Lopes ◽  
Andrews José de Lucena ◽  
Francisco Mendonça

Characterizing the behaviour of the sea breeze phenomenon is the foremost factor in the reduction in the heat stress and the achievement of the pleasant environment in coastal cities globally. However, this seminal study shows that the Sea Breeze Front (SBF) development can be related to an increase in outdoor thermal discomfort in a northeastern Brazilian city during summer. We explored the relationship between SBF and thermal comfort conditions using in situ meteorological observations, the SBF identification method, local climate zones (LCZs) classification, and the Physiological Equivalent Temperature (PET) thermal comfort index. SBF days and Non-SBF days were characterized in terms of weather conditions, combining meteorological data and technical bulletins. SBF days included hot and sunny days associated with the centre of the Upper Tropospheric Cyclonic Vortices (UTCV). In contrast, Non-SBF days were observed in UTCV’s periphery because of cloudy sky and rainfall. The results showed that the mean temperature and PET in the SBF days were 2.0 °C and 3.8 °C higher, respectively, compared to Non-SBF days in all LCZ sites. The highest PET, of 40.0 °C, was found on SBF days. Our findings suggest that SBF development could be an aggravating factor for increasing heat stress of the people living in the northeastern coast of the Brazilian city, after SBF passage.


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