The study area covers the province of Muğla and a small part of Antalya located in the farthest south – west part of Turkey (36003´- 37000N and 28012´- 29025´E; Fig. 1). The area shelters world famous summer beach tourism resorts and also ancient city of Lycian with a recorded history dating back to 5th century BC at east Mediterranean. Total number of tourists visiting the area is 3.266.650 in 2019.
Meteorological data was obtained from the meteorological stations operated by the official meteorology authority, Turkish State Meteorological Service and established in the settlements (districts) of Fethiye (3m MSL), Dalaman (6m MSL), Koycegiz (4m MSL), Marmaris (16m MSL), Bodrum (26m MSL), Datca (30m MSL), Seydikemer (124m MSL), Kas (153m MSL), Mugla-Mentese (646m MSL), Yatagan (650m MSL) and Elmalı (1050m MSL).
Stations
|
Coordinates
|
Elevation (m, AMSL)
|
Fethiye
|
36°37'36.5"N 29°07'26.0"E
|
3m
|
Dalaman
|
36°46'18.8"N 28°47'55.0"E
|
6m
|
Koycegiz
|
36°58'12.0"N 28°41'12.8"E
|
4m
|
Marmaris
|
36°50'22.2"N 28°14'42.7"E
|
16m
|
Bodrum
|
37°01'58.1"N 27°26'23.3"E
|
26m
|
Datca
|
36°42'28.1"N 27°41'30.1"E
|
30m
|
Seydikemer
|
36°38'57.1"N 29°21'14.0"E
|
124m
|
Kas
|
36°12'00.7"N 29°39'00.7"E
|
153m
|
Mugla-Mentese
|
37°12'34.2"N 28°22'00.5"E
|
646m
|
Yatagan
|
37°20'22.2"N 28°08'12.8"E
|
650m
|
Elmalı
|
36°44'13.9"N 29°54'43.6"E
|
1050m
|
https://mgm.gov.tr/kurumsal/istasyonlarimiz.aspx?il=Mu%C4%9Fla |
https://mgm.gov.tr/kurumsal/istasyonlarimiz.aspx?il=Antalya
Study area has Mediterranean climate characteristics, very hot, dry and long summers with an average annual temperature 34oC, cool and wet winters with an average annual temperature of 17oC. The coldest month is January and the warmest month is July in the study area. Annual rainfall changes between 750 mm and 1200 mm in the area while relative humidity is around 75% all year and sunshine duration is 140 h in winter and 360 h in summer period. The prevailing wind direction is West daytime and East at night from sea and land respectively. Average wind velocity is about 3.5 m/sec. Geography of the study area is diverse causing different types of nature landscapes covering mountains which run perpendicularly to the sea coast and valleys open to the sea winds.
MUGLA
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Jun
|
Jul
|
Aug
|
Sep
|
Oct
|
Nov
|
Dec
|
Annual
|
|
Measurement period (1928 - 2020)
|
Mean temperature (°C)
|
5.3
|
6.1
|
8.5
|
12.7
|
17.7
|
22.8
|
26.4
|
26.2
|
21.9
|
16.2
|
10.8
|
7.0
|
15.1
|
Mean max. tenp. (°C)
|
9.8
|
10.9
|
14.2
|
18.8
|
24.3
|
29.6
|
33.4
|
33.5
|
29.2
|
23.1
|
16.6
|
11.5
|
21.2
|
Mean min. temp. (°C)
|
1.6
|
1.9
|
3.6
|
7.0
|
11.4
|
16.1
|
19.7
|
19.6
|
15.3
|
10.3
|
5.9
|
3.2
|
9.6
|
Mean sunshine duration (hour)
|
3.5
|
4.5
|
5.8
|
7.3
|
8.7
|
10.6
|
11.4
|
11.0
|
9.5
|
6.9
|
4.8
|
3.4
|
7.3
|
Mean wet days
|
15.5
|
13.2
|
11.5
|
9.7
|
8.5
|
4.1
|
2.0
|
1.7
|
2.9
|
7.2
|
9.9
|
14.7
|
100.9
|
Total rainfall (mm)
|
241.4
|
178.6
|
123.1
|
64.7
|
50.9
|
24.5
|
11.7
|
14.7
|
23.3
|
73.4
|
136.5
|
265.5
|
1208.3
|
|
Measurement period (1928 - 2020)
|
Record maximum temp. (°C)
|
20.9
|
25.5
|
28.8
|
31.2
|
39.4
|
40.8
|
42.1
|
41.2
|
39.2
|
36.8
|
29.0
|
23.8
|
42.1
|
Record minimum temp (°C)
|
-12.6
|
-9.9
|
-8.5
|
-3.6
|
1.0
|
6.7
|
10.5
|
9.0
|
5.6
|
0.1
|
-7.0
|
-9.0
|
-12.6
|
Method
At the first stage of the study, all related meteorological data i.e. Ta (°C), RH (%), wind velocity (m/sec) were obtained from the meteorological measurement stations at 12 sites on hourly basis over 10 years (between 2010 – 2020) in the hottest period of the year between May and October. Mean radiant temperature (Tmrt; °C) and PET (°C) values were calculated through the software, Rayman 3.2 (Matzarakis et al. 2010), which can estimate radiation fluxes considering microclimatological modifications of different outdoor environments. While evaluating the PET and Tmrt, different elevations were also evaluated in the study. In addition to obtained meteorological values mentioned above, parameters of clothing (set to 0.9 clo in summer and 1.0 clo in winter), activity (set to 80 w) and global radiation (Gr) were set in the Rayman to calculate PET and Tmrt values.
Tmrt which is defined as the ‘uniform temperature of an imaginary enclosure in which the radiant heat transfer from the human body equals the radiant heat transfer in the actual non-uniform enclosure has been widely adopted for urban thermal comfort studies (Massomoido and Mazaus 2004; Thorsson et al. 2014; Emmanuel et al.2007). Tmrt better describes the spatial thermal pattern within complex urban environment than the air temperature and it also indicates the heat stress and heat related mortality better in clear and warm conditions with high solar irradiance in especially summer season (Winslow et al. 1936; Clark and Edholm 1985; Kolchi1996; Matzarakis 2000; Thorsson et al. 2014; Keny et al. 2008; Vanos et al. 2010). Tmrt is affected by shadows generated by vegetation cover, buildings, topography and surface materials therefore urban green spaces offer advantages for Tmrt against UHI or for the moderation of urban climatic conditions (Luchesa et al. 2016; Rodriguez et al. 2016; Xi et al. 2012 Zhang et al. 2018).
Before the calculation of PET and Tmrt, wind data was adjusted to those at 1.1 m according to the generally adopted empirical formula for human biometeorology (Nikapolia and Lykodis 2007).
W1.1.= w10(1.1./10)(0.12z0+0.18) ; where W1.1 is the estimated wind velocity at 1.1 m, W10 is the wind velocity measured at 10 m, and zo is the surface roughness depending on the characteristics of the study area.
A dataset including PET and Tmrt values was used to prepare coloured graphics and then transformed to GIS software, ArcGis 9.3 to determine the spatial distribution of human thermal comfort conditions calculated. With the help of ArcGis 9.3 software, measurement points were digitized considering national coordinate system. Inverse distance weighted (IDW) belonging to spatial analysis module in ArcGis 9.3 software was applied for the distribution of PET and Tmrt in the study area. IDW interpolation determines cell values using linear weighted combination set of same points (Chang et al. 2006; Yang et al. 2008). The weight is a function of inverse distance. The surface being interpolated is location – dependent variable. The use of IDW provides control over the points with known values to estimate the interpolation values based on their distances from the source point. The IDW function offers 2 options; a fixed search Radius type and a variable search radius type. With a fixed radius, the radius of the circle used to find input points is the same for each interpolated cell. A higher power puts much emphasis on the nearest point, creating a surface that has more details but is less smooth. A lower power gives much influence to surrounding points that are farther away, creating a smooth surface. It makes search radius variable for each interpolated cell depending upon how far it has to stretch to obtain specified number of input points. It determines a maximum distance to limit the potential size of the radius of the circle.
For the interpolation of temperature values according to elevation, the following formula was used to calculate temperature values;
Tr = Ti ± (hi * 0.005)
Tr= Reduced temperature with height;
Ti= Station mean temperature;
hi= Station height (Demircan et al. 2011).
The rates of adiabatic heating and cooling in the atmosphere are described as lapse rates and are expressed as the change of temperature with elevation. The adiabatic lapse rate for dry air is very close to 1°C per 100 m. If vapour condensation occurs in the air parcel, latent heat is released, thereby modifying the rate of temperature change. This retarded rate is called the pseudo-adiabatic lapse rate; it is not a constant for its value depends on the temperature at which the process takes place and the amount of water vapour in the air mass. However, for general descriptive purposes it is assumed as 0.5°C per 100 m (Oliver and Fainbridge 2005).
Even though 24-hour calculation of PET and Tmrt was performed, only daytime values were analysed in the study in order to determine the situation to which the locals and visitors are exposed in the most disadvantageous period for human thermal comfort. For the categorisation of PET values into thermal stress levels, the ranges given in Table 1 were used.
Table 1
Human thermal sensation and stress ranges for PET (Matzarakis and Mayer 1996; Matzarakis et al. 1999; Höppe, 1999; Matzarakis et al.2007).
PET [°C]
|
Thermal sensation
|
Level of thermal stress
|
< 4°C
|
very cold
|
extreme cold stress
|
4.1 - 8°C
|
cold
|
strong cold stress
|
8.1 - 13°C
|
cool
|
moderate cold stress
|
13.1 - 18°C
|
slightly cool
|
slight cold stress
|
18.1 - 23°C
|
neutral (comfortable)
|
no thermal stress
|
23.1 - 29°C
|
slightly warm
|
slight heat stress
|
29.1 - 35°C
|
warm
|
moderate heat stress
|
35.1 - 41°C
|
hot
|
strong heat stress
|
41°C >
|
very hot
|
extreme heat stress
|