Urban Design and Outdoor Thermal Comfort in Warm Climates. Studies in Fez and Colombo
(2006)- Abstract
- In many developing tropical countries, rapid urban growth leads to several problems, including increased thermal stress. This has negative consequences for people's health and well-being, and affects social and commercial outdoor activities negatively. Consequently, the creation of thermally comfortable microclimates in urban environments is highly important.
The main aim of this thesis is to deepen our knowledge regarding the relationship between urban design, microclimate and outdoor thermal comfort through studies conducted in the hot dry climate of Fez, Morocco, and the hot humid climate of Colombo, Sri Lanka. Both cities have highly uncomfortable climates and are experiencing problems of rapid population growth,... (More) - In many developing tropical countries, rapid urban growth leads to several problems, including increased thermal stress. This has negative consequences for people's health and well-being, and affects social and commercial outdoor activities negatively. Consequently, the creation of thermally comfortable microclimates in urban environments is highly important.
The main aim of this thesis is to deepen our knowledge regarding the relationship between urban design, microclimate and outdoor thermal comfort through studies conducted in the hot dry climate of Fez, Morocco, and the hot humid climate of Colombo, Sri Lanka. Both cities have highly uncomfortable climates and are experiencing problems of rapid population growth, leading to considerable horizontal expansion of urban development, characterised by inefficient land-use.
The research methodology in this study included a combination of microclimate measurements, numerical microclimate simulations and studies of the urban planning process. Field measurements were conducted in areas with significantly differing characteristics, including variations in urban geometry and distance to the sea, to map variations in microclimate and outdoor thermal comfort within each city. To cover a wider range of urban design, to test the impact of different design parameters on outdoor thermal comfort and to achieve optimum design solutions, microclimate simulations using the ENVI-met software were conducted. The urban codes were analysed to determine whether they favour or hinder climate-conscious urban design, while the interviews with urban planners and designers aimed at investigating the extent to which climate aspects are included in urban design.
Microclimate conditions and thermal comfort at street level were found to vary considerably within both Fez and Colombo. Apart from its old city, Fez is a dispersed city dominated by street canyons with low height-to-width ratios. This study shows that new urban areas would need to be far more compact than today's to improve the microclimatic conditions during the warm season. However, deep canyons should be blended with shallower, east-west oriented canyons, as well as shallow open spaces to allow solar access in the winter. In Colombo, the urban form is also dispersed and a more compact form with deeper canyons is needed to improve microclimatic conditions. However, spacing between buildings is necessary to allow air flow. Shallow, east-west oriented canyons are needed near the coastal strip to enable the westerly sea breeze to penetrate the city. In both cities, design details, such as colonnades and shading trees, are important to improve pedestrians? thermal comfort.
The dispersed urban form in both Fez and Colombo is the result of regulations regarding building heights, street widths, plot coverage and setbacks. The current urban codes do not favour a comfortable microclimate in either of the cities and would need to be changed to allow deeper street canyons and to promote the horizontal shading of pedestrians. Such a change would lead to higher building and population densities, which is in line with the aims of the national authorities in both countries. The consideration of climate aspects is limited at all planning levels in both cities. There is a need to educate professionals in climate-conscious urban planning and to develop detailed urban design guidelines and easy-to-use design tools. (Less) - Abstract (Swedish)
- Popular Abstract in Swedish
I många utvecklingsländer i tropiska klimat leder den snabba urbaniseringen till många problem, bl a försämrad termisk komfort i utemiljön. Detta har negativa följder för människors hälsa och välbefinnande och påverkar sociala och kommersiella aktiviteter utomhus negativt. Följaktligen är det mycket viktigt att åstadkomma komfortabla mikroklimat i urban miljö.
Den huvudsakliga målsättningen med denna studie är att fördjupa kunskapen vad gäller förhållandet mellan stadsbyggnad och mikroklimatet i gatunivå genom studier i varmt och torrt klimat, representerat av Fes i Marocko, och varmt och fuktigt klimat, representerat av Colombo i Sri Lanka. Dessa båda städer kännetecknas av... (More) - Popular Abstract in Swedish
I många utvecklingsländer i tropiska klimat leder den snabba urbaniseringen till många problem, bl a försämrad termisk komfort i utemiljön. Detta har negativa följder för människors hälsa och välbefinnande och påverkar sociala och kommersiella aktiviteter utomhus negativt. Följaktligen är det mycket viktigt att åstadkomma komfortabla mikroklimat i urban miljö.
Den huvudsakliga målsättningen med denna studie är att fördjupa kunskapen vad gäller förhållandet mellan stadsbyggnad och mikroklimatet i gatunivå genom studier i varmt och torrt klimat, representerat av Fes i Marocko, och varmt och fuktigt klimat, representerat av Colombo i Sri Lanka. Dessa båda städer kännetecknas av okomfortabelt uteklimat samt problem med snabb befolkningstillväxt vilket har lett till betydande horisontell utbredning kännetecknad av ineffektivt markutnyttjande.
Forskningsmetodiken i denna studie innefattar en kombination av mätningar och simuleringar av mikroklimatet samt studier av urbaniseringsprocessen. Fältmätningar utfördes i områden med betydande skillnader i bl a urban form och avstånd till havet för att kartlägga variationer i mikroklimat och termisk komfort inom varje stad. För att täcka ett bredare spektrum av urban form, för att testa inverkan av olika designparametrar och för att uppnå optimala lösningar gjordes simuleringar av mikroklimatet med dataprogrammet ENVI-met. De urbana normerna analyserades för att utröna huruvida de stimulerar eller hindrar en klimatanpassad stadsbyggnad och intervjuer med planerare gjordes för att undersöka till vilken utsträckning klimataspekter beaktas inom urban planering.
Mikroklimatet och den termiska komforten i gatunivån visade sig variera kraftigt i såväl Fes som Colombo. Fes är, bortsett från den gamla stadskärnan, en till stora delar glest bebyggd stad. Denna studie visar att nya urbana områden skulle behöva ha smalare gator eller högre byggnader än vad som är brukligt idag för att för att uppnå ett bättre mikroklimat under den varma årstiden. Smala gator måste dock kombineras med dels bredare gator orienterade i öst-västlig riktning, dels medelstora öppna platser för att garantera solinstrålning i gatunivå vintertid. Även Colombo är en glest bebyggd stad där en tätare bebyggelse behövs för att förbättra mikroklimatet. Det är dock viktigt med tillräckliga avstånd mellan husen för att öka luftrörelserna i gatunivå. Vidare behövs breda gator orienterade i öst-västlig riktning nära kustremsan för att möjliggöra för den västliga sjöbrisen att nå djupare in i staden. I båda städerna är detaljer i gatumiljön såsom arkader och skuggträd viktiga för att förbättra den termiska komforten för fotgängare.
Den glesa stadsstrukturen i såväl Fes som Colombo är resultatet av regler gällande byggnadshöjd, gatubredder och hur stor del av tomten som får bebyggas. I båda städerna motverkar de urbana normerna ett komfortabelt mikroklimat och dessa regler skulle därför behöva revideras, dels för att tillåta en tätare bebyggelse i form av smalare gator eller högre byggnader, dels för att föreskriva en utformning av gaturummet som garanterar skugga åt fotgängare. Sådana normändringar skulle även leda till större befolkningsdensitet vilket eftersträvas av myndigheterna i båda länderna. Beaktandet av klimataspekter visade sig vara begränsat på alla planeringsnivåer i både Fes och Colombo. Följaktligen finns det ett behov av att utbilda yrkesverksamma i klimatanpassad urban planering samt att utveckla detaljerade riktlinjer för klimatanpassad stadsbyggnad och användarvänliga designverktyg. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/547094
- author
- Johansson, Erik LU
- supervisor
- opponent
-
- Professor Steemers, Koen, The Martin Centre for Architectural and Urban Studies, Dept. of Architecture, University of Cambridg
- organization
- publishing date
- 2006
- type
- Thesis
- publication status
- published
- subject
- keywords
- marklära, geomorfologi, Fysisk geografi, climatology, cartography, pedology, geomorphology, Physical geography, Urban planning, Urban design, Urban climate, Tropical areas, Thermal comfort, Sri Lanka, Planning regulations, Morocco, Microclimates, Land-use, Fez, Humid tropics, Colombo, Developing countries, Climatic design, Climate, Arid zones, Built environment, Physical planning, kartografi, klimatologi, Town and country planning, Stads- och glesbygdsplanering, Fysisk planering
- pages
- 237 pages
- publisher
- Housing development & management
- defense location
- Lilla hörsalen Ingvar Kamprad Designcentrum Sölvegatan 26, Lunds tekniska högskola.
- defense date
- 2006-09-15 10:15:00
- ISBN
- 91-87866-27-7
- language
- English
- LU publication?
- yes
- id
- ed0f969a-2d9b-40a0-a0c0-153b5fa38bd4 (old id 547094)
- date added to LUP
- 2016-04-01 16:20:34
- date last changed
- 2023-11-14 15:48:27
@phdthesis{ed0f969a-2d9b-40a0-a0c0-153b5fa38bd4, abstract = {{In many developing tropical countries, rapid urban growth leads to several problems, including increased thermal stress. This has negative consequences for people's health and well-being, and affects social and commercial outdoor activities negatively. Consequently, the creation of thermally comfortable microclimates in urban environments is highly important.<br/><br> <br/><br> The main aim of this thesis is to deepen our knowledge regarding the relationship between urban design, microclimate and outdoor thermal comfort through studies conducted in the hot dry climate of Fez, Morocco, and the hot humid climate of Colombo, Sri Lanka. Both cities have highly uncomfortable climates and are experiencing problems of rapid population growth, leading to considerable horizontal expansion of urban development, characterised by inefficient land-use.<br/><br> <br/><br> The research methodology in this study included a combination of microclimate measurements, numerical microclimate simulations and studies of the urban planning process. Field measurements were conducted in areas with significantly differing characteristics, including variations in urban geometry and distance to the sea, to map variations in microclimate and outdoor thermal comfort within each city. To cover a wider range of urban design, to test the impact of different design parameters on outdoor thermal comfort and to achieve optimum design solutions, microclimate simulations using the ENVI-met software were conducted. The urban codes were analysed to determine whether they favour or hinder climate-conscious urban design, while the interviews with urban planners and designers aimed at investigating the extent to which climate aspects are included in urban design.<br/><br> <br/><br> Microclimate conditions and thermal comfort at street level were found to vary considerably within both Fez and Colombo. Apart from its old city, Fez is a dispersed city dominated by street canyons with low height-to-width ratios. This study shows that new urban areas would need to be far more compact than today's to improve the microclimatic conditions during the warm season. However, deep canyons should be blended with shallower, east-west oriented canyons, as well as shallow open spaces to allow solar access in the winter. In Colombo, the urban form is also dispersed and a more compact form with deeper canyons is needed to improve microclimatic conditions. However, spacing between buildings is necessary to allow air flow. Shallow, east-west oriented canyons are needed near the coastal strip to enable the westerly sea breeze to penetrate the city. In both cities, design details, such as colonnades and shading trees, are important to improve pedestrians? thermal comfort.<br/><br> <br/><br> The dispersed urban form in both Fez and Colombo is the result of regulations regarding building heights, street widths, plot coverage and setbacks. The current urban codes do not favour a comfortable microclimate in either of the cities and would need to be changed to allow deeper street canyons and to promote the horizontal shading of pedestrians. Such a change would lead to higher building and population densities, which is in line with the aims of the national authorities in both countries. The consideration of climate aspects is limited at all planning levels in both cities. There is a need to educate professionals in climate-conscious urban planning and to develop detailed urban design guidelines and easy-to-use design tools.}}, author = {{Johansson, Erik}}, isbn = {{91-87866-27-7}}, keywords = {{marklära; geomorfologi; Fysisk geografi; climatology; cartography; pedology; geomorphology; Physical geography; Urban planning; Urban design; Urban climate; Tropical areas; Thermal comfort; Sri Lanka; Planning regulations; Morocco; Microclimates; Land-use; Fez; Humid tropics; Colombo; Developing countries; Climatic design; Climate; Arid zones; Built environment; Physical planning; kartografi; klimatologi; Town and country planning; Stads- och glesbygdsplanering; Fysisk planering}}, language = {{eng}}, publisher = {{Housing development & management}}, school = {{Lund University}}, title = {{Urban Design and Outdoor Thermal Comfort in Warm Climates. Studies in Fez and Colombo}}, url = {{https://lup.lub.lu.se/search/files/4643420/547096.pdf}}, year = {{2006}}, }