The role of urban morphology on outdoor thermal comfort: The case of Al-Sharq City – Az Zarqa

Urban Climate ◽  
2020 ◽  
Vol 34 ◽  
pp. 100706 ◽  
Author(s):  
Hanin Abdel Salam Othman ◽  
Abdulsalam Ahmad Alshboul
Keyword(s):  
Thermal Comfort ◽  
Urban Morphology ◽  
Outdoor Thermal Comfort

scholarly journals Revealing Urban Morphology and Outdoor Comfort through Genetic Algorithm-Driven Urban Block Design in Dry and Hot Regions of China

2019 ◽  
Vol 11 (13) ◽  
pp. 3683 ◽  
Author(s):  
Xiaodong Xu ◽  
Chenhuan Yin ◽  
Wei Wang ◽  
Ning Xu ◽  
Tianzhen Hong ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Thermal Comfort ◽  
Block Design ◽  
Urban Morphology ◽  
Dust Storms ◽  
Outdoor Thermal Comfort ◽  
Climate Index ◽  
Actual Case ◽  
Simulation And Optimization ◽  
Hot Climate

In areas with a dry and hot climate, factors such as strong solar radiation, high temperature, low humidity, dazzling light, and dust storms can tremendously reduce people’s thermal comfort. Therefore, researchers are paying more attention to outdoor thermal comfort in urban environments as part of urban design. This study proposed an automatic workflow to optimize urban spatial forms with the aim of improvement of outdoor thermal comfort conditions, characterized by the universal thermal climate index (UTCI). A city with a dry and hot climate—Kashgar, China—is further selected as an actual case study of an urban block and Rhino & Grasshopper is the platform used to conduct simulation and optimization process with the genetic algorithm. Results showed that in summer, the proposed method can reduce the averaged UTCI from 31.17 to 27.43 °C, a decrease of about 3.74 °C, and reduce mean radiation temperature (MRT) from 43.94 to 41.29 °C, a decrease of about 2.65 °C.

PERANAN UNSUR-UNSUR RUANG TERBUKA PADA TINGKAT KENYAMANAN TERMAL OUTDOOR: ANTARA PERSEPSI DAN PENGETAHUAN

2018 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Floriberta Binarti ◽  
Hanson E Kusuma ◽  
Surjamanto Wonorahardjo ◽  
Sugeng Triyadi
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Spatial Perception ◽  
Psychological Adaptation ◽  
Comfort Level ◽  
Anthropogenic Heat ◽  
Outdoor Thermal Comfort ◽  
Online Questionnaire ◽  
Comfort Perception

Abstract: Surface morphology, surface material, greenery, anthropogenic heat and air pollutants are known as the elements that determine the thermal environment performance. These elements, hence, should determine the outdoor thermal comfort level. However, previous studies mentioned that the role of psychological adaptation in outdoor thermal comfort is greater than in the indoor. Therefore, exploring perceived elements, which determine the thermal environment, could enrich the perspective of a design approach of thermally comfortable open spaces. This study aims to explore the perceived elements of thermal environment, which contribute to the outdoor thermal comfort using open-ended questions of an online questionnaire. Several keywords obtained by the content analysis of 101 respondents’ answers affirm the role of the thermal environment elements in modifying the thermal environment. Tree or greenery, the most frequently appeared keyword, showed as the strongest perceived element. New keywords that significantly appeared; i.e. visual aspects, supporting facilities, and tranquility; indicate the importance of thermo-spatial perception approach in designing livable and thermally comfortable outdoor environment.Keywords: elements of thermal environment, outdoor thermal comfort, perception, psychological adaptation,Abstraksi: Morfologi permukaan, permukaan material, area hijau, panas antropogenik dan polutan udara diketahui sebagai elemen-elemen yang menentukan performansi lingkungan termal. Dengan demikian, elemen-elemen tersebut seharusnya menentukan tingkat kenyamanan termal outdoor. Namun, beberapa studi menyebutkan peranan adaptasi psikis pada kenyamanan termal outdoor yang lebih besar dibandingkan pada kenyamanan termal indoor. Oleh karenanya, eksplorasi elemen-elemen yang dipersepsikan menentukan lingkungan termal dapat memperkaya perspektif pendekatan studi ruang terbuka yang nyaman secara termal. Studi ini bertujuan untuk menggali elemen-elemen lingkungan termal yang dipersepsikan berperan pada kenyamanan termal outdoor dengan menggunakan pertanyaan-pertanyaan yang bersifat open-ended di dalam kuesioner online. Beberapa kata kunci yang dihasilkan oleh analisis konten dari 101 responden mengkonfirmasi peranan elemen-elemen lingkungan termal di dalam memodifikasi lingkungan termal. Pohon atau greenery, kata kunci yang paling sering muncul, menunjukkan sebagai elemen yang dipersepsikan paling kuat. Kata kunci baru yang muncul secara signifikan, yaitu: aspek visual, fasilitas penunjang, dan ketenangan; mengindikasikan pentingnya pendekatan persepsi termo-spasial di dalam merancang lingkungan outdoor yang hidup dan nyaman secara termal.Kata kunci: adaptasi psikis, kenyamanan termal outdoor, persepsi, unsur-unsur lingkungan termal

Assessing the Impact of Vegetation in the Visibility Connection and Thermal Comfort in the Urban Outdoors (Case Study: Shafagh Park)

2021 ◽  
Author(s):  
Alireza Karimi ◽  
Darya Gachkar ◽  
Sadaf Gachkar ◽  
soheila aghlemand
Keyword(s):  
Thermal Comfort ◽  
Urban Parks ◽  
Climatic Conditions ◽  
Outdoor Thermal Comfort ◽  
Favorable Conditions ◽  
The Impact ◽  
The Relationship ◽  
Good Visibility

Abstract Regarding the significant impact of visibility, landscape, and thermal comfort on the presence of users’ attendance in urban parks, there is a severe interest in studies on the amount of visibility and the outdoor thermal comfort especially in a district with hot summers. this research, after investigating the shafagh park based on space laws and the relationship between park spaces with each other in terms of accessibility and visibility to achieve the effect of plants, then, based on the obtained data, the role of plants in evaluating thermal comfort conditions in the park space was investigated and finally, their relationship with each other has been examined. results have revealed that, plants have an undeniable role in improving the conditions of thermal comfort and visual visibility and user movement in spaces, so that, the best points in terms of thermal comfort, had a favorable view and perspective, while, areas of the park that did not have good visibility and landscape did not experience favorable conditions in terms of thermal comfort. Therefore, architects, landscape architects, and urban designers who research the problem of thermal comfort and landscape analysis in urban parks can use the findings of this article for effective outcomes, especially in parks with climatic conditions use similar in Tehran.

Impact of different sub-tropical trees on outdoor thermal comfort in an Indian city – A microclimatic modelling approach

2021 ◽  
Author(s):  
Sana Javaid ◽  
Kameswara Yashaswini Sista ◽  
Stephan Pauleit
Keyword(s):  
Thermal Comfort ◽  
Tree Species ◽  
Tree Height ◽  
Urban Trees ◽  
Urban Setting ◽  
Outdoor Thermal Comfort ◽  
Climatic Zones ◽  
Urban Settings ◽  
Modelling Approach

<p>Indians cities are facing incessant urbanization with lack of adequate green spaces exposing inhabitants to heat stress and increased mortality. Reduction of heat stress or optimization of outdoor thermal comfort (OTC) has been recognized as one of the multiple benefits of urban green infrastructure across different climatic zones. However, there is dearth of such studies in humid-subtropical (Cwa) context, especially India. ‘Urban trees’ are most preferred vegetation type concerning OTC, whereas, ‘parks, streets and gardens’ are most preferred urban green settings in a residential neighbourhood, as indicated by social survey results of another part of this study. But role of urban trees in enhancing OTC in different urban settings remains underexplored. In particular, it needs to be better understood how different morphological characteristics of trees influence their thermal benefits. Hence, we investigated nine sub-tropical tree species in these urban settings of a typical residential neighbourhood in the mid-sized, humid-subtropical city of Dehradun in north India. A sizeable world population inhabits humid-subtropical climates and almost 1/3rd of Indians reside in mid-size cities, making this study widely relevant.</p><p>We used a modelling approach enabling comparison of different trees in similar urban settings which is not possible through on-ground studies. 70 tree species were identified through field surveys and further filtered based on frequency, canopy density, morphology and growth habit. Finally, nine species were selected, three for each urban setting and modelled using Albero, a plugin of the 3D microclimatic simulation software, ENVI-met. Parameters such as tree height, trunk height, canopy shape and density, leaf area density, root spread and diameter etc. were considered for tree modelling. Modelling was validated using the field measurements and indicated a high correlation of 90%. Total nine scenarios were created using ENVI-met for each tree species in the respective urban setting maintaining canopy cover area. Their performance was evaluated by air temperature, relative humidity and mean radiant temperature at 15:00 and 19:00 hours of a peak summer day (2nd July 2019). Thermal comfort was also evaluated using PET (Physiologically Equivalent Temperature) between 9:00-20:00 hours. </p><p>Our results indicate that Mangifera Indica, Azadirachta Indica and Alstonia Scholaris perform best on an average for all parameters in gardens, park and streets respectively. These three trees had dense canopy i.e. high leaf area density (LAD) values and an average tree height between 11-15m. It should be noted that we did not have trees bigger than 15m on our site so results need to be further verified for taller trees. It can, however, be inferred that LAD value and tree height influenced cooling benefits more than trunk height or canopy shape in all urban settings. These results will be used to explore most suitable plantation arrangement in these urban settings. We acknowledge limitation of tree modelling using a software, however, forthcoming ENVI-Met 2021 release will enable detailed tree modelling and further improvise the study. Our results can be used in green space planning in humid subtropical climatic zones with similar urban settings or for further exploration of role of urban tree species. </p>

scholarly journals How to Improve the Liveability in Cities: The Effect of Urban Morphology and Greening on Outdoor Thermal Comfort

2021 ◽  
Vol 65 (2-4) ◽  
pp. 361-370
Author(s):  
Guglielmina Mutani ◽  
Valeria Todeschi ◽  
Simone Beltramino
Keyword(s):  
Built Environment ◽  
Thermal Comfort ◽  
Energy Savings ◽  
Green Roofs ◽  
Urban Morphology ◽  
Outdoor Thermal Comfort ◽  
Water Runoff ◽  
Physiological Equivalent Temperature ◽  
The Impact ◽  
The City

Extensive and intensive green roofs and vegetated walls should be used to improve the livability in cities, especially in densely built-up context, in order to optimize their contribution on energy savings and greenhouse gas emissions, improving thermal comfort conditions and ensuring a greater storm-water runoff. The aim of this study is to evaluate the effect of urban morphology and to quantify the impact of green surfaces and plants on outdoor thermal comfort conditions. The analysis was applied to six neighborhoods in the city of Turin, identified as typical districts with different building geometries, urban contexts and green presence. The outdoor thermal comfort conditions were assessed calculating a set of indicators, such as the predicted mean vote and the physiological equivalent temperature, with the support of ENVI-met tool. Retrofit scenarios were hypothesized, and outdoor thermal comfort conditions were investigated before and after the installation of green roofs and vegetated areas. The result allowed to understand how thermal comfort vary, considering the building geometry, urban morphology, and green areas in different zones of the city of Turin. By analyzing neighborhoods, it is possible to identify the optimal built environment that ensure better thermal comfort conditions. These models and tools could support urban planners in defining the best measures to improve the liveability and quality in the built environment considering local constraints and the real characteristics of the territory or in designing new neighborhoods.

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