lii
employed can be divided into three main types of intervention, namely buildings,
pavements and vegetation.
As for buildings, the mitigation of their effects on urban heat islands are primarily related to the changes of material properties, as well as on the geometry of the
urban settings created by buildings themselves (street sections and urban canyons).
The first of the aforementioned strategies mainly deals with the thermal performance
of buildings, while the other is mainly related with the way in which air currents can
remove excess heat from areas between buildings (streets, passageways, etc.).
Pavements in turn play a very important role in the formation of the UHI phenomenon, since conventional paving materials (concrete and asphalt among the others)
tend to absorb large amounts of solar radiation during daytime and to release it to
the cooler surrounding air at night. Another important property of paving materials
is their limited permeability to water, which prevents water absorption in the ground,
thus reducing the potential evaporation of the ground surface which may contribute
to the reduction of air temperatures. Last but not least, trees and vegetation in general reduces ambient air temperature mainly by evapo-transpiration and shading and
is therefore expected to help in the mitigation process of UHI intensity. The common practices within this scope are the planting of trees and vegetation in an existing urban fabric (city streets and car-parkings) or the creation and preservation of
wider green areas (parks, groves, lawns, etc.) within the urban fabric.
UHI is obviously a common problem for Europe on a continental scale. Pilot
actions brought together the most relevant metropolitan areas in Central Europe for
a kind of shared study of the urban heat island phenomenon and for a joint experimentation of countermeasures.
UHI project structure deals also with the comparison of the impact of potential
mitigation measures of the urban heat island through the use of different modelling
tools in order to give a quantitative evaluation of the reduction of UHI intensity
implementing the mitigation strategies. These estimate may also be an innovative
strategy in order to support local stakeholders thus contributing to bridge the gap
between two traditionally unrelated disciplines such as meteo-climatology and
urban planning. The development of traditional meteorological models and the
analysis of relative outputs can in turn contribute to the definition of specific strategies to guide the choice of urban development and renewal.
The core of UHI project can be stated as an effort to create a positive relationship
between knowledge and actions. Policy-making is a very complicated process partly
due to the wide range of topics and uncertainty in the scientific results. Research in
UHI project should aim at gaining a greater understanding of the complexities of
meteorological issues with respect to mesoscale interactions, primarily at the urban
boundary layer. One of the goal of this attention is certainly paid to put in place
energy-efficiency and energy-saving approaches in urban and territorial planning.
In addition, systematic and interdisciplinary applied research can help policy
makers to gather intelligence and to monitor and evaluate the efficacy of their
approaches. On the other hand, policy makers in urbanized and urbanizing regions
Introduction
employed can be divided into three main types of intervention, namely buildings,
pavements and vegetation.
As for buildings, the mitigation of their effects on urban heat islands are primarily related to the changes of material properties, as well as on the geometry of the
urban settings created by buildings themselves (street sections and urban canyons).
The first of the aforementioned strategies mainly deals with the thermal performance
of buildings, while the other is mainly related with the way in which air currents can
remove excess heat from areas between buildings (streets, passageways, etc.).
Pavements in turn play a very important role in the formation of the UHI phenomenon, since conventional paving materials (concrete and asphalt among the others)
tend to absorb large amounts of solar radiation during daytime and to release it to
the cooler surrounding air at night. Another important property of paving materials
is their limited permeability to water, which prevents water absorption in the ground,
thus reducing the potential evaporation of the ground surface which may contribute
to the reduction of air temperatures. Last but not least, trees and vegetation in general reduces ambient air temperature mainly by evapo-transpiration and shading and
is therefore expected to help in the mitigation process of UHI intensity. The common practices within this scope are the planting of trees and vegetation in an existing urban fabric (city streets and car-parkings) or the creation and preservation of
wider green areas (parks, groves, lawns, etc.) within the urban fabric.
UHI is obviously a common problem for Europe on a continental scale. Pilot
actions brought together the most relevant metropolitan areas in Central Europe for
a kind of shared study of the urban heat island phenomenon and for a joint experimentation of countermeasures.
UHI project structure deals also with the comparison of the impact of potential
mitigation measures of the urban heat island through the use of different modelling
tools in order to give a quantitative evaluation of the reduction of UHI intensity
implementing the mitigation strategies. These estimate may also be an innovative
strategy in order to support local stakeholders thus contributing to bridge the gap
between two traditionally unrelated disciplines such as meteo-climatology and
urban planning. The development of traditional meteorological models and the
analysis of relative outputs can in turn contribute to the definition of specific strategies to guide the choice of urban development and renewal.
The core of UHI project can be stated as an effort to create a positive relationship
between knowledge and actions. Policy-making is a very complicated process partly
due to the wide range of topics and uncertainty in the scientific results. Research in
UHI project should aim at gaining a greater understanding of the complexities of
meteorological issues with respect to mesoscale interactions, primarily at the urban
boundary layer. One of the goal of this attention is certainly paid to put in place
energy-efficiency and energy-saving approaches in urban and territorial planning.
In addition, systematic and interdisciplinary applied research can help policy
makers to gather intelligence and to monitor and evaluate the efficacy of their
approaches. On the other hand, policy makers in urbanized and urbanizing regions
Introduction