Urban Green Areas – their functions under a changing lifestyle of ...

a hotel, the public body manage the land must trade off the benefits ahead of business to a
public space (the park). In almost all cities, this essentially political trade-off is not easy to
arrange.
2.5 Urban comfort
The term “urban comfort” describes not another benefit additionally to those mentioned
above of UGAs. HONJO (2009: 43) states that there is a rising demand on studies on urban
comfort for outdoor environment in the recent context of “changing climate and increase of
heat stress in cities”. Main purpose of studying urban comfort is to find the environmental
conditions pleasurable the people. Then planners need to calculate how much the benefit a
park provides to comfort every single person and number of residents living around the
park. For example, people feel comfortable at certain temperature, humidity and wind
speed, these are urban comfort; then how much area of trees or lake is enough to create a
micro climate matching with the certain urban comfort.
Urban comfort is assessed by a number of indices based on empirical data. For example,
Standard Effective Temperatures, outdoor Standard Effective Temperatures, Predicted
Mean Vote, Predicted Mean Values and the Physiological Equivalent Temperature are the
most common indices currently used (see MERTENS 1999: 4119, HWANG et. al. 2010).
HONJO (2009) reviews applications of the broadest indices, Standard Effective
Temperatures, Predicted Mean Vote and Physiological Equivalent Temperature. He
concludes that there “remain problems in the assessment of outdoor comfort indices”, the
three indices “have proven suitable for application at the current state of the art” (HONJO
2009: 46).
Such indices are necessary to summarise data and to make the benefits manageable for city
planning and parks design. Thermal comfort has been studied in fourteen European cities
(NIKOLOPOULOU/LYKOUDIS 2006) and both thermal and acid climate in Asian
(AMED 2003), African (HASSAAN/MAHMOUD 2011) and European cities (COHEN
2012; PANTANOU 2011). Those studies illuminate that thermal comfort is a major issue in
UGA research with important implications for city planning and park design.
Thermal comfort is studied in fourteen European cities (NIKOLOPOULOU/LYKOUDIS
2006). Several specific case studies for hot and acid climate in Asian (AMED 2003),
African (HASSAAN/MAHMOUD 2011) and European cities (COHEN 2012;
PANTANOU 2011) elaborate related issues. Those studies illuminate that thermal comfort
is a vivid issue in studies on UGAs. It either demonstrates for social benefit, or city
planning as well as park designing. Due to “Outdoor spaces are important to sustainable
cities because they accommodate pedestrian traffic and outdoor activities, and contribute
greatly to urban liveability and vitality” (CHEN/EDWARD 2012).
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