Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City

One of the greatest issues nowadays is that of the urban heat island effect on the thermal conditions inside cities. The air temperature inside the city core is warmer than that in suburbs, thus deteriorating the quality of life for citizens and making outdoor spaces uncomfortable in terms of therma...

Full description

Bibliographic Details
Main Authors: Georgios Kalogeropoulos, Argiro Dimoudi, Pavlos Toumboulidis, Stamatis Zoras
Format: Article
Language:English
Published: MDPI AG 2022-07-01
Series:Atmosphere
Subjects:
Online Access:https://www.mdpi.com/2073-4433/13/7/1102
_version_ 1827597909344911360
author Georgios Kalogeropoulos
Argiro Dimoudi
Pavlos Toumboulidis
Stamatis Zoras
author_facet Georgios Kalogeropoulos
Argiro Dimoudi
Pavlos Toumboulidis
Stamatis Zoras
author_sort Georgios Kalogeropoulos
collection DOAJ
description One of the greatest issues nowadays is that of the urban heat island effect on the thermal conditions inside cities. The air temperature inside the city core is warmer than that in suburbs, thus deteriorating the quality of life for citizens and making outdoor spaces uncomfortable in terms of thermal comfort. This phenomenon is usually assessed in large scale cities worldwide and less often in medium-sized towns. The current study aimed to investigate the urban heat island effect and, therefore, to assess the outdoor thermal comfort conditions in a medium-sized city. More specifically, the methodology of the current study includes: (i) the combination of different monitoring techniques to quantify the urban heat island effect in a medium-sized Mediterranean city. Both in situ measurements and remote sensing techniques were applied to assess the urban heat island effect in terms of both the canopy layer (CUHI) and the surface (SUHI); (ii) the identification of the parameters that affect thermal comfort and the identification of the most appropriate bioclimatic indices that determine outdoor thermal comfort in the city of interest. Both questionnaire survey and in situ measurements took place on a sidewalk in the city of Xanthi, Northern Greece, during the summer. The CUHI effect was obvious, especially in the morning and afternoon. Downscaled MODIS satellite images also showed that the intensity of SUHI was higher in the morning and afternoon. Apart from air temperature, important differences in the values of most microclimatic parameters were recorded between the meteorological station placed inside the urban area and those gathered from a nearby meteorological station. The narrow roads, the thermal properties of construction materials, and the absence of greenery characterized the area of interest and may be the key factors creating these differences in climate. Concerning the thermal comfort assessment, the most significant parameters were the air temperature and solar radiation, although, both empirical and direct indices were found to describe the comfort values well. According to the results, downscaling techniques are also important for the SUHI effect to be investigating in detail in medium-sized urban environments.
first_indexed 2024-03-09T03:42:03Z
format Article
id doaj.art-013c32e93e034c46908f02dd5b71c17a
institution Directory Open Access Journal
issn 2073-4433
language English
last_indexed 2024-03-09T03:42:03Z
publishDate 2022-07-01
publisher MDPI AG
record_format Article
series Atmosphere
spelling doaj.art-013c32e93e034c46908f02dd5b71c17a2023-12-03T14:38:55ZengMDPI AGAtmosphere2073-44332022-07-01137110210.3390/atmos13071102Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean CityGeorgios Kalogeropoulos0Argiro Dimoudi1Pavlos Toumboulidis2Stamatis Zoras3Department of Environmental Engineering, Democritus University of Thrace, 67100 Xanthi, GreeceDepartment of Environmental Engineering, Democritus University of Thrace, 67100 Xanthi, GreeceDepartment of Environmental Engineering, Democritus University of Thrace, 67100 Xanthi, GreeceDepartment of Environmental Engineering, Democritus University of Thrace, 67100 Xanthi, GreeceOne of the greatest issues nowadays is that of the urban heat island effect on the thermal conditions inside cities. The air temperature inside the city core is warmer than that in suburbs, thus deteriorating the quality of life for citizens and making outdoor spaces uncomfortable in terms of thermal comfort. This phenomenon is usually assessed in large scale cities worldwide and less often in medium-sized towns. The current study aimed to investigate the urban heat island effect and, therefore, to assess the outdoor thermal comfort conditions in a medium-sized city. More specifically, the methodology of the current study includes: (i) the combination of different monitoring techniques to quantify the urban heat island effect in a medium-sized Mediterranean city. Both in situ measurements and remote sensing techniques were applied to assess the urban heat island effect in terms of both the canopy layer (CUHI) and the surface (SUHI); (ii) the identification of the parameters that affect thermal comfort and the identification of the most appropriate bioclimatic indices that determine outdoor thermal comfort in the city of interest. Both questionnaire survey and in situ measurements took place on a sidewalk in the city of Xanthi, Northern Greece, during the summer. The CUHI effect was obvious, especially in the morning and afternoon. Downscaled MODIS satellite images also showed that the intensity of SUHI was higher in the morning and afternoon. Apart from air temperature, important differences in the values of most microclimatic parameters were recorded between the meteorological station placed inside the urban area and those gathered from a nearby meteorological station. The narrow roads, the thermal properties of construction materials, and the absence of greenery characterized the area of interest and may be the key factors creating these differences in climate. Concerning the thermal comfort assessment, the most significant parameters were the air temperature and solar radiation, although, both empirical and direct indices were found to describe the comfort values well. According to the results, downscaling techniques are also important for the SUHI effect to be investigating in detail in medium-sized urban environments.https://www.mdpi.com/2073-4433/13/7/1102urban heat islandthermal comfortthermal remote sensingland surface temperaturequestionnaire surveyin situ measurements
spellingShingle Georgios Kalogeropoulos
Argiro Dimoudi
Pavlos Toumboulidis
Stamatis Zoras
Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City
Atmosphere
urban heat island
thermal comfort
thermal remote sensing
land surface temperature
questionnaire survey
in situ measurements
title Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City
title_full Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City
title_fullStr Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City
title_full_unstemmed Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City
title_short Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City
title_sort urban heat island and thermal comfort assessment in a medium sized mediterranean city
topic urban heat island
thermal comfort
thermal remote sensing
land surface temperature
questionnaire survey
in situ measurements
url https://www.mdpi.com/2073-4433/13/7/1102
work_keys_str_mv AT georgioskalogeropoulos urbanheatislandandthermalcomfortassessmentinamediumsizedmediterraneancity
AT argirodimoudi urbanheatislandandthermalcomfortassessmentinamediumsizedmediterraneancity
AT pavlostoumboulidis urbanheatislandandthermalcomfortassessmentinamediumsizedmediterraneancity
AT stamatiszoras urbanheatislandandthermalcomfortassessmentinamediumsizedmediterraneancity