A review of the Impact of Blue Space on the Urban Microclimate

The urban heat island (UHI) phenomenon represents a major public health issue and has received great attention due to rapid urbanisation. Blue spaces have long been considered a possible mitigation strategy to ameliorate the UHI. However, our knowledge regarding the interaction of waterbodies with their urban surroundings is still limited. This review attempts through a comparative analysis of the available literature to examine the thermal effects of static blue spaces on the urban climate. Remote sensing studies are the most common approach analysed in this review but there is a clear disparity between the cooling potentials reported by remote sensing as opposed to field measurements or numerical simulations, likely due to a lack of nocturnal measurements, when warming due to thermal inertia can occur and consideration of the latent heat flux. The size and shape of blue spaces are shown to be important variables for the cooling achieved in urban settings but there is no consensus in the literature. This is likely due to the different locations and climates of the studies, it can be hypothesised that in locations with an even distribution of wind directions a rounder waterbody is more effective while in locations where wind direction is more uniform an elongated waterbody aligned to the wind is more effective due to the increased fetch. From the analysis of the literature, it is clear that there is still a distinct knowledge gap regarding the physical interpretation of waterbodies’ contribution to the urban climate. There is also a current lack of information about the diurnal and seasonal variability of the various structures and processes. There is evidence, however, that the comfort achieved by sensible cooling can be offset by the increased water vapour content and that during the night blue spaces may actually exacerbate the UHI, reducing urban thermal comfort

A review of the Impact of Blue Space on the Urban Microclimate

The urban heat island (UHI) phenomenon represents a major public health issue and has received great attention due to rapid urbanisation. Blue spaces have long been considered a possible mitigation strategy to ameliorate the UHI. However, our knowledge regarding the interaction of waterbodies with their urban surroundings is still limited. This review attempts through a comparative analysis of the available literature to examine the thermal effects of static blue spaces on the urban climate. Remote sensing studies are the most common approach analysed in this review but there is a clear disparity between the cooling potentials reported by remote sensing as opposed to field measurements or numerical simulations, likely due to a lack of nocturnal measurements, when warming due to thermal inertia can occur and consideration of the latent heat flux. The size and shape of blue spaces are shown to be important variables for the cooling achieved in urban settings but there is no consensus in the literature. This is likely due to the different locations and climates of the studies, it can be hypothesised that in locations with an even distribution of wind directions a rounder waterbody is more effective while in locations where wind direction is more uniform an elongated waterbody aligned to the wind is more effective due to the increased fetch. From the analysis of the literature, it is clear that there is still a distinct knowledge gap regarding the physical interpretation of waterbodies’ contribution to the urban climate. There is also a current lack of information about the diurnal and seasonal variability of the various structures and processes. There is evidence, however, that the comfort achieved by sensible cooling can be offset by the increased water vapour content and that during the night blue spaces may actually exacerbate the UHI, reducing urban thermal comfort

Thermal Efficiency of Courtyards for Residential Buildings in Iraq

This thesis investigates adopting the courtyard pattern in Iraq to provide a thermally efficient architectural solution that contributes towards solving the housing challenges in the country. As a result of more than three decades of wars and instability, the country suffers from having a large housing shortage and a major production shortfall. This shortage is estimated at around 1.0 million housing units, which is equivalent to one-quarter of the total housing stock in the country. The current housing production is around 30000 housing units per annum only, which, therefore, does not alleviate the housing needs in the country. The country has developed a new national housing policy and adopted the mass construction of multi-family buildings as an architectural solution towards solving the large quantitative problems. This research aimed to investigate the potential thermal efficiency of courtyards with considering this housing context. To achieve this aim, this research started by investigating the housing context in Iraq. It, then, focussed on the use of courtyards in modern multi-family residential buildings in Iraq, and explored the level of thermal comfort that courtyards can offer to Iraqi residents. The study developed a novel Courtyard Thermal Usability Index (CTUI) to quantify the ability of courtyards to offer a thermally comfortable environment to occupants. CTUI is the fraction of thermally comfortable hours in a courtyard to the total occupation hours during a specific period. To underpin the quantification, the research conducted a thermal comfort survey in Iraq and carried out a series of simulation experiments. The aim of the survey was to determine the thermal comfort limits of Iraqis to be used in judging the thermal efficiency of courtyards. The aim of the simulation was to explore the thermal conditions of courtyards in Iraq. Two simulation tools, Envi-met and IES-VE, were used to determine the thermal conditions across a search space of 360 different courtyard variants. The simulation experiments were conducted for Baghdad and six other Iraqi cities of different climatic conditions. The tested courtyards represent a wide range of possible courtyard geometric configurations, which enabled the research to provide a good overview of possible thermal conditions of courtyards in Iraq. The survey results indicate that the minimum and maximum thermally comfortable globe temperatures for Iraqis in winter and summer are, respectively 14 °C and 35 °C. Within this comfort range and during the daily occupation hours, which are from 8:00 to 22:00, the annual CTUI of courtyards, in Baghdad, ranges between 0.16 and 0.38. Expressed in a different way, courtyards can offer 875 - 2078 comfortable hours out of 5470 occupation hours per annum. The rest are not comfortable hours, mostly due to overheating. In comparison to current typical urban settings, courtyards offer higher levels of thermal comfort. The most effective geometric property on courtyards’ thermal conditions and the level of thermal comfort in courtyards is the width/height ratio. This ratio has a significant impact on the insolation level and Mean Radiant Temperature, which highly affect the thermal sensation of occupants. In conclusion, this research suggests that the courtyard can help to provide thermally comfortable environments for occupants in Iraq. However, other passive and active strategies need to be considered as courtyards are not comfortable for around two-thirds of the occupation hours around the year. This research advances the knowledge on the acceptable thermal comfort conditions in residential buildings in Iraq through presenting the first complete thermal comfort survey in residential buildings in the country. This research presents the first attempt towards a holistic and comprehensive assessment of thermal comfort in courtyards.The Higher Committee of Education Development in Iraq (HCED

Proceedings of the 9th Arab Society for Computer Aided Architectural Design (ASCAAD) international conference 2021 (ASCAAD 2021): architecture in the age of disruptive technologies: transformation and challenges.

The ASCAAD 2021 conference theme is Architecture in the age of disruptive technologies: transformation and challenges. The theme addresses the gradual shift in computational design from prototypical morphogenetic-centered associations in the architectural discourse. This imminent shift of focus is increasingly stirring a debate in the architectural community and is provoking a much needed critical questioning of the role of computation in architecture as a sole embodiment and enactment of technical dimensions, into one that rather deliberately pursues and embraces the humanities as an ultimate aspiration

Urban naturalistic meadows to promote cultural and regulating ecosystem services

This thesis examined the ecosystem services delivered by a new type of vegetation comprised of grasses and forbs organised in biodiverse naturalistic meadows. The study site was a 500 metres retrofitted linear greenway, the Grey to Green, installed in Sheffield (UK) city centre. A street survey showed users highly appreciated the vegetation and had an improved the perception of the urban environment and thus established the delivery of cultural ecosystem services. By means of a questionnaire and micro-climatic measurements, a thermal sensation scale for Sheffield was defined. In addition to evidence for the role of physiological acclimatisation, a link was found between appreciation of the green space and tolerance to thermal discomfort. The influence of psychological factors on thermal comfort was further investigated using a visual questionnaire. Results highlighted interactions between thermal preference, thermal expectation, landscape appreciation and long-term experience. The microclimatic regulating services of meadows was demonstrated via a yearlong comparative study of surface temperature against that of shaded and exposed turf and concrete. The results highlighted meadows have a measurable impact on reducing the Urban Heat Island effect; and, at times, more efficiently so than trees. The environmental simulation software Envi-Met was tested against field data and was showed to predict realistically surface temperature. This thesis demonstrated the usefulness of urban meadows in cultural and regulating ecosystem services delivery. They may ease surface heat accumulation, improve perceptual qualities of the urban environment and improve the sensation of thermal comfort. Thus, they contribute to making cities more liveable

Urban naturalistic meadows to promote cultural and regulating ecosystem services

This thesis examined the ecosystem services delivered by a new type of vegetation comprised of grasses and forbs organised in biodiverse naturalistic meadows. The study site was a 500 metres retrofitted linear greenway, the Grey to Green, installed in Sheffield (UK) city centre. A street survey showed users highly appreciated the vegetation and had an improved the perception of the urban environment and thus established the delivery of cultural ecosystem services. By means of a questionnaire and micro-climatic measurements, a thermal sensation scale for Sheffield was defined. In addition to evidence for the role of physiological acclimatisation, a link was found between appreciation of the green space and tolerance to thermal discomfort. The influence of psychological factors on thermal comfort was further investigated using a visual questionnaire. Results highlighted interactions between thermal preference, thermal expectation, landscape appreciation and long-term experience. The microclimatic regulating services of meadows was demonstrated via a yearlong comparative study of surface temperature against that of shaded and exposed turf and concrete. The results highlighted meadows have a measurable impact on reducing the Urban Heat Island effect; and, at times, more efficiently so than trees. The environmental simulation software Envi-Met was tested against field data and was showed to predict realistically surface temperature. This thesis demonstrated the usefulness of urban meadows in cultural and regulating ecosystem services delivery. They may ease surface heat accumulation, improve perceptual qualities of the urban environment and improve the sensation of thermal comfort. Thus, they contribute to making cities more liveable

Climate-Led Urban Landscape Planning: A Simulation Data-driven Analytics, Design and Decision-Making Process for Ipoh, Malaysia

芝浦工業大

Empirical and Computational Issues of Microclimate Simulation

Part 1: Information & Communication Technology-EurAsia Conference 2014, ICT-EurAsia 2014International audienceThe dynamic variability of weather conditions and complex geometry and semantics of urban domain impose significant constraints on the empirical study of urban microclimate. Thus, numerical modeling is being increasingly deployed to capture the very dynamics of urban microclimate. In this context, the present paper illustrates the basic processes of calibrating and preparing a numerical model for the simulation of the urban microclimate