scholarly journals Study of urban microclimate conditions in a commercial area of an urban centre and the environmental regeneration potential

2021 ◽  
Vol 899 (1) ◽  
pp. 012017
Author(s):  
Th Rapti ◽  
A Kantzioura
Keyword(s):  
Geographical Location ◽  
Urban Morphology ◽  
Specific Humidity ◽  
Urban Centre ◽  
Urban Microclimate ◽  
The Road ◽  
Urban Geometry ◽  
Commercial Area ◽  
Urban Heat ◽  
Air Speed

Abstract Urban heat island (UHI) is a phenomenon that affects the urban microclimate. Land use, urban geometry, cover materials, vegetation, the water element and human activities are the most important factors that affect the UHI. This research focused on the study and analysis of the urban microclimate of three sections of a commercial street area that differ in their morphology. The first area includes a stream near the road, the second area includes the purely commercial part of the street and the third area includes the fringes of a hill in (Thessaloniki, “Toumpa”, Gr Lampraki Street). Using the Envimet V4 program, three simulations were performed for the selected study areas for the hottest day of the previous year, August 1, 2020. The values with the largest variations in all three areas were those of relative and specific humidity and finally air speed. The air temperature was higher in relation to the suburban area (UHI) and did not show significant differences in the three study areas. This leads us to the conclusion that the urban morphology, orientation and geographical location of the three study areas played the most important role in shaping the urban microclimate. Finally, is suggested one alternative scenario for optimizing the microclimate in the most burdened area of the three.

scholarly journals A study case of urban heat island intensity based on urban geometry

2019 ◽  
Author(s):  
Le Minh Tuan ◽  
Ilkhomzhon Shukurov ◽  
Nguyen Thi Mai
Keyword(s):  
Urban Heat Island ◽  
Negative Impact ◽  
Maximum Intensity ◽  
Heat Island ◽  
Model Calculations ◽  
The Road ◽  
Island Effect ◽  
Urban Geometry ◽  
Urban Heat ◽  
The City

Introduction. The paper presents a method to simulate the maximum intensity of urban heat island (UHI) based on urban geometry using H/W parameters, where H — building height and W — width of neighboring street. Urban heat island is determined by the increase in the temperature in the city centers compared to the surrounding rural areas. Materials and methods. The research is based on remote sensing technology to analyze the thermal surface of Hanoi city. It was run in different seasons thereby determining the expansion of the heat island effect over the years. The research method is based on Oke’s model number theory. An area is selected in the city center with high construction density to simulate the intensity of UHI. Results. The study shows that population growth affects the urbanization process. Over the years the urban land area is affected by the expansion of the heat island effect. Based on Oke’s model, calculations of UHI maximum intensity in Nhan Chinh block (Thanh Xuan district of Hanoi) were made. The estimation showed that the higher the building and the greater the distance from the road, the greater the intensity of the heat island. Accordingly, the lower the building and the smaller the distance from the road, the lower the intensity of the heat island. Conclusions. Using the Oke’s model to estimate heat island intensity based on the height-to-distance ratio of a building to a road makes process modeling possible. As a result, the planner can offer solutions to eliminate the negative impact of the urban heat island effect.

scholarly journals URBAN MICROCLIMATE IMPROVEMENT USING ENVI-MET CLIMATE MODEL

2018 ◽  
Vol XLII-4 ◽  
pp. 69-76 ◽  
Author(s):  
E. Chatzinikolaou ◽  
C. Chalkias ◽  
E. Dimopoulou
Keyword(s):  
Thermal Comfort ◽  
Urban Environment ◽  
Climate Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Urban Morphology ◽  
Urban Microclimate ◽  
3D Space ◽  
Roadside Vegetation ◽  
Urban Heat

<p><strong>Abstract.</strong> The aim of this paper is the modelling of urban microclimate, based on the limits imposed by the complexity of the three-dimensional space of cities. To this purpose, different Bioclimatic Scenarios were investigated through the microclimatic simulations using the micro-scale numerical model, ENVI-met 4v, applied in a case study of a Block in a highly residential neighbourhood of Athens. The study compares the bioclimatic scenarios of the roof top and road side vegetation plan in the current conditions, in order to evaluate how the existence of vegetation can affect the local air temperature and the thermal comfort condition of urban environment. This study also highlights the need to manage those microclimate data, through a geodatabase and provides a GIS approach of data organization and visualization. Creating building facades of the distributed temperature has showed that urban morphology parameters have an obvious impact on temperature distribution in the 3D space. On the other hand, the proposed roadside vegetation scenario has proved to be the most suitable way to improve the thermal comfort conditions of urban environment, as it can eliminate the Urban Heat Island (UHI) effects.</p>

scholarly journals The Urban Heat Island phenomenon modelling and analysis as an adaptation of Maghreb cities to climate change

2018 ◽  
Vol 149 ◽  
pp. 02090 ◽  
Author(s):  
Kaoutar Ouali ◽  
Khalid El Harrouni ◽  
Moulay Larbi Abidi ◽  
Youssef Diab
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
City Planning ◽  
Urban Morphology ◽  
Heat Island ◽  
Urban Microclimate ◽  
Simulation Tools ◽  
Analysis And Evaluation ◽  
Urban Heat ◽  
The Subject

The modeling of the urban microclimate, in particular the phenomenon of the Urban Heat Island (UHI), is becoming increasingly essential for city planning and urban design. The phenomenon analysis is henceforth possible thanks to the increase in computational power, the link between simulation tools and urban databases, which allow to represent explicitly the characteristics of the urban microclimate and to better understand its effects, through the analysis and evaluation of the different impacts of the urban climatic or anthropogenic contributors (urban morphology, land use, building sites, albedo, …). However, the choice of the scaleof the study depends on a balance between the precision of the modeling, the capacities of calculation and the availability and reliability of the data.The UHI phenomenon has been the subject of several research studies in the European countries since the 2000s. Thispaper focuses mainly on the description of the phenomenon, the different methodsused to evaluate and modeled its impacts, using some approaches for mitigating these ones.The contribution aims to highlight the phenomenon of the UHI based on a bibliographic study of the latest research on this topic in Maghreb cities.The state of art focuses on the progress made during the last 15 years taking into account the UHI in the different strategies for adapting cities to climate change and for improving their resilience.

scholarly journals Quantitative Analysis of Factors Contributing to Urban Heat Island Intensity

2012 ◽  
Vol 51 (5) ◽  
pp. 842-854 ◽  
Author(s):  
Young-Hee Ryu ◽  
Jong-Jin Baik
Keyword(s):  
Urban Heat Island ◽  
Single Layer ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Impervious Surfaces ◽  
Additional Heat ◽  
Urban Geometry ◽  
Causative Factors ◽  
Urban Heat ◽  
Vertical Walls

AbstractThis study identifies causative factors of the urban heat island (UHI) and quantifies their relative contributions to the daytime and nighttime UHI intensities using a mesoscale atmospheric model that includes a single-layer urban canopy model. A midlatitude city and summertime conditions are considered. Three main causative factors are identified: anthropogenic heat, impervious surfaces, and three-dimensional (3D) urban geometry. Furthermore, the 3D urban geometry factor is subdivided into three subfactors: additional heat stored in vertical walls, radiation trapping, and wind speed reduction. To separate the contributions of the factors and interactions between the factors, a factor separation analysis is performed. In the daytime, the impervious surfaces contribute most to the UHI intensity. The anthropogenic heat contributes positively to the UHI intensity, whereas the 3D urban geometry contributes negatively. In the nighttime, the anthropogenic heat itself contributes most to the UHI intensity, although it interacts strongly with other factors. The factor that contributes the second most is the impervious-surfaces factor. The 3D urban geometry contributes positively to the nighttime UHI intensity. Among the 3D urban geometry subfactors, the additional heat stored in vertical walls contributes most to both the daytime and nighttime UHI intensities. Extensive sensitivity experiments to anthropogenic heat intensity and urban surface parameters show that the relative importance and ranking order of the contributions are similar to those in the control experiment.

scholarly journals The Psychosocial and Somatic Effects of Relocation from Remote Canadian First Nation Communities to Urban Centres on Indigenous Peoples with Chronic Kidney Disease (CKD)

2021 ◽  
Vol 18 (7) ◽  
pp. 3838
Author(s):  
Denise Genereux ◽  
Lida Fan ◽  
Keith Brownlee
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Indigenous Peoples ◽  
Health Care Professionals ◽  
Medical Condition ◽  
Geographical Location ◽  
Well Being ◽  
First Nation ◽  
Urban Centre ◽  
The Impact

Chronic kidney disease, also referred to as end-stage renal disease (ESRD), is a prevalent and chronic condition for which treatment is necessary as a means of survival once affected individuals reach the fifth and final stage of the disease. Dialysis is a form of maintenance treatment that aids with kidney functioning once a normal kidney is damaged. There are two main types of dialysis: hemodialysis (HD) and peritoneal dialysis (PD). Each form of treatment is discussed between the patient and nephrologist and is largely dependent upon the following factors: medical condition, ability to administer treatment, supports, geographical location, access to necessary equipment/supplies, personal wishes, etc. For Indigenous Peoples who reside on remote Canadian First Nation communities, relocation is often recommended due to geographical location and limited access to both health care professionals and necessary equipment/supplies (i.e., quality of water, access to electricity/plumbing, etc). Consequently, the objective of this paper is to determine the psychosocial and somatic effects for Indigenous Peoples with ESRD if they have to relocate from remote First Nation communities to an urban centre. A review of the literature suggests that relocation to urban centres has negative implications that are worth noting: cultural isolation, alienation from family and friends, somatic issues, psychosocial issues, loss of independence and role adjustment. As a result of relocation, it is evident that the impact is profound in terms of an individuals’ mental, emotional, physical and spiritual well-being. Ensuring that adequate social support and education are available to patients and families would aid in alleviating stressors associated with managing chronic kidney disease.

Arcades City: Early-Modern City Planning Practice of Wuzhou

2014 ◽  
Vol 641-642 ◽  
pp. 616-619
Author(s):  
Ji Li ◽  
Bai Hao Li ◽  
Li Lin
Keyword(s):  
Early Modern ◽  
City Planning ◽  
Planning Process ◽  
Early Stage ◽  
Road Construction ◽  
Urban Morphology ◽  
Planning Theory ◽  
Modern City ◽  
The Road ◽  
Historic City

With regard to planning theory and practical construction of Early-modern City Planning in Wuzhou, the paper discusses the historic city regeneration was adhere to old city structure and regional resource at early stage, and new planning refer to technology of ideal cities in Europe and America later. It also analyzes the urban morphology for the "Road Construction→Historic City Renovation→Experimental Regional Planning" process, summarizes the activities of Wuzhou early-modern city planning and construction has “Arcades City” characteristic.

scholarly journals Seasonal and Diurnal Variations in the Relationships between Urban Form and the Urban Heat Island Effect

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5909
Author(s):  
Ze Liang ◽  
Yueyao Wang ◽  
Jiao Huang ◽  
Feili Wei ◽  
Shuyao Wu ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Form ◽  
Urban Heat Island Effect ◽  
Dominant Factor ◽  
Heat Island ◽  
Relative Contribution ◽  
Island Effect ◽  
Urban Geometry ◽  
Seasonal And Diurnal Variations ◽  
Urban Heat

At the city scale, the diurnal and seasonal variations in the relationship between urban form and the urban heat island effect remains poorly understood. To address this deficiency, we conducted an empirical study based on data from 150 cities in the Jing-Jin-Ji region of China from 2000 to 2015. The results derived from multiple regression models show that the effects of urban geometric complexity, elongation, and vegetation on urban heat island effect differ among different seasons and between day and night. The impacts of urban geometric factors and population density in summer, particularly those during the daytime, are significantly larger than those in winter. The influence of urban area and night light intensity is greater in winter than in summer and is greater during the day than at night. The effect of NDVI is greater in summer during the daytime. Urban vegetation is the factor with the greatest relative contribution during the daytime, and urban size is the dominant factor at night. Urban geometry is the secondary dominant factor in summer, although its contribution in winter is small. The relative contribution of urban geometry shows an upward trend at a decadal time scale, while that of vegetation decreases correspondingly. The results provide a valuable reference for top-level sustainable urban planning.

scholarly journals Local Weather Types by Thermal Periods: Deepening the Knowledge about Lisbon’s Urban Climate

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 840
Author(s):  
Cláudia Reis ◽  
António Lopes ◽  
Ezequiel Correia ◽  
Marcelo Fragoso
Keyword(s):  
Hot Spots ◽  
Urban Areas ◽  
Urban Climate ◽  
Specific Humidity ◽  
Air Masses ◽  
Air Temperatures ◽  
Hourly Data ◽  
Urban Heat ◽  
Thermal Patterns ◽  
Local Weather

Urbanized hot spots incorporate a great diversity of microclimates dependent, among other factors, on local meteorological conditions. Until today, detailed analysis of the combination of climatic variables at local scale are very scarce in urban areas. Thus, there is an urgent need to produce a Local Weather Type (LWT) classification that allows to exhaustively distinguish different urban thermal patterns. In this study, hourly data from air temperature, wind speed and direction, accumulated precipitation, cloud cover and specific humidity (2009–2018) were integrated in a cluster analysis (K-means) in order to produce a LWT classification for Lisbon’s urban area. This dataset was divided by daytime and nighttime and thermal periods, which were generated considering the annual cycle of air temperatures. Therefore, eight LWT sets were generated. Results show that N and NW LWT are quite frequent throughout the year, with a moderate speed (daily average of 4–6 m/s). In contrast, the frequency of rainy LWT is considerably lower, especially in summer (below 10%). Moreover, during this season the moisture content of the air masses is higher, particularly at night. This methodology will allow deepening the knowledge about the multiple Urban Heat Island (UHI) patterns in Lisbon.

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