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4.1 Introduction
Urban areas, with their artificial materials and specific morphology, act as an obstacle to the atmosphere, altering energy-balance, the chemical composition as well as
the wind field (Landsberg 1981; Oke 1982; Oke and Cleugh 1987; Helbig et al.
1999). The urban heat island (UHI), describing the urban-rural surface and air temperature differences, is the most prominent and world-wide studied phenomenon of
urban climate (eg Böhm and Gabl 1978; Katsoulis and Theoharatos 1985; Kuttler
et al. 1996; Runnalls and Oke 2000; Johansson and Emmanuel 2006).
In fact, the intensity of the urban heat island depends on eg land-use, building
ratio, population density and vegetation (eg Landsberg 1981; Oke 1981; 1982;
1988). Before establishing mitigation and adaptation measures counteracting the
urban heat island, city planners and officials need to comprehend the spatial and
temporal dimensions of the meteorological and climatological conditions in a city
(Matzarakis et al. 2008; Ketterer and Matzarakis 2014a, b). As city dwellers are the
main target of city planners, the integral effect of air temperature, air humidity, wind
speed and radiation fluxes on humans in a city has to be quantified and assessed
(Eliasson 2000; Ketterer and Matzarakis 2014a, b). Hence, modern humanbiometeorological methods for quantification of the spatial and temporal distribution of the UHI as well as to assess mitigation and adaptation measures for improving
outdoor meteorological conditions have to be applied (Kuttler 2011, 2012;
Matzarakis 2013).
Urban planners require information about the human biometeorological conditions in terms of frequencies (eg number of days or hours per year or season), as
well as the quantification of temperature differences between different planning
scenarios Fröhlich and Matzarakis (2011, 2013). The quantification of heat stress
and its reduction by planning measures is a big challenge, especially in the light of
climate change (Matzarakis and Endler 2010). Due to climate change, the mean air
temperature is expected to increase and also heat waves are assumed to became
more frequent, more intense and longer lasting (Matzarakis and Amelung 2008;
Meehl and Tebaldi 2004; Schär et al. 2004; Muthers and Matzarakis 2010;
Matzarakis and Nastos 2011). Thus, there is a demand for the assessment and quantification of adaptation measures improving the urban climate, ie street morphology,
different types of vegetation (Hwang et al. 2011; Ketterer et al. 2013; Lin et al.
2012; Matzarakis 2001, 2006, 2007, 2010). This approach is twofold: the analysis
and description of single places for urban planning measures and the construction
of maps for the detection of areas with frequent heat stress (Svensson et al. 2003).
The aim is to show and describe methods based on long term measured data and
their analysis for a comprehensive quantification of urban-rural differences and
possible strategies for adaptation and mitigation in urban areas, focused on micro
scale conditions.
A. Matzarakis et al.
4.1 Introduction
Urban areas, with their artificial materials and specific morphology, act as an obstacle to the atmosphere, altering energy-balance, the chemical composition as well as
the wind field (Landsberg 1981; Oke 1982; Oke and Cleugh 1987; Helbig et al.
1999). The urban heat island (UHI), describing the urban-rural surface and air temperature differences, is the most prominent and world-wide studied phenomenon of
urban climate (eg Böhm and Gabl 1978; Katsoulis and Theoharatos 1985; Kuttler
et al. 1996; Runnalls and Oke 2000; Johansson and Emmanuel 2006).
In fact, the intensity of the urban heat island depends on eg land-use, building
ratio, population density and vegetation (eg Landsberg 1981; Oke 1981; 1982;
1988). Before establishing mitigation and adaptation measures counteracting the
urban heat island, city planners and officials need to comprehend the spatial and
temporal dimensions of the meteorological and climatological conditions in a city
(Matzarakis et al. 2008; Ketterer and Matzarakis 2014a, b). As city dwellers are the
main target of city planners, the integral effect of air temperature, air humidity, wind
speed and radiation fluxes on humans in a city has to be quantified and assessed
(Eliasson 2000; Ketterer and Matzarakis 2014a, b). Hence, modern humanbiometeorological methods for quantification of the spatial and temporal distribution of the UHI as well as to assess mitigation and adaptation measures for improving
outdoor meteorological conditions have to be applied (Kuttler 2011, 2012;
Matzarakis 2013).
Urban planners require information about the human biometeorological conditions in terms of frequencies (eg number of days or hours per year or season), as
well as the quantification of temperature differences between different planning
scenarios Fröhlich and Matzarakis (2011, 2013). The quantification of heat stress
and its reduction by planning measures is a big challenge, especially in the light of
climate change (Matzarakis and Endler 2010). Due to climate change, the mean air
temperature is expected to increase and also heat waves are assumed to became
more frequent, more intense and longer lasting (Matzarakis and Amelung 2008;
Meehl and Tebaldi 2004; Schär et al. 2004; Muthers and Matzarakis 2010;
Matzarakis and Nastos 2011). Thus, there is a demand for the assessment and quantification of adaptation measures improving the urban climate, ie street morphology,
different types of vegetation (Hwang et al. 2011; Ketterer et al. 2013; Lin et al.
2012; Matzarakis 2001, 2006, 2007, 2010). This approach is twofold: the analysis
and description of single places for urban planning measures and the construction
of maps for the detection of areas with frequent heat stress (Svensson et al. 2003).
The aim is to show and describe methods based on long term measured data and
their analysis for a comprehensive quantification of urban-rural differences and
possible strategies for adaptation and mitigation in urban areas, focused on micro
scale conditions.
A. Matzarakis et al.