Quantification of Artificial Surfaces Impact on Urban Heat Island of Novi Sad ( Vojvodina , Serbia )

Introduction It is crucial in land cover and climate change research to systematically describe the environment in order to detect its changes, human-related causes and responses. Earth’s land surface and its changes are central in most of the biophysical processes of global environmental change. Therefore, land change is qualified as a forcing function within the global environmental change (Grugia et al., 2010, Jansen and Di Gregorio, 2002; Turner, 2002; Turner, 2006). Land cover has been defined by the attributes of the Earth’s land surface and immediate subsurface, including biota, soil, topography, surface and groundwater, and human (mainly built-up) structure (Lambin et al., 2006). This paper analyse land cover patches and urban temperature intensity of the City of Novi Sad (Vojvodina, Serbia). The main purpose of the analyses is to quantify land cover patches within zones of annual mean urban heat island (UHI) temperature intensity of Novi Sad. Quantified land cover patches are bringing most useful information about state of UHI that is impacted by human influences.


Introduction
It is crucial in land cover and climate change research to systematically describe the environment in order to detect its changes, human-related causes and responses.Earth's land surface and its changes are central in most of the biophysical processes of global environmental change.Therefore, land change is qualified as a forcing function within the global environmental change (Grugia et al., 2010, Jansen andDi Gregorio, 2002;Turner, 2002;Turner, 2006).
Land cover has been defined by the attributes of the Earth's land surface and immediate subsurface, including biota, soil, topography, surface and groundwater, and human (mainly built-up) structure (Lambin et al., 2006).
This paper analyse land cover patches and urban temperature intensity of the City of Novi Sad (Vojvo-dina, Serbia).The main purpose of the analyses is to quantify land cover patches within zones of annual mean urban heat island (UHI) temperature intensity of Novi Sad.Quantified land cover patches are bringing most useful information about state of UHI that is impacted by human influences.using ArcGIS 9.3 software.Quantification of landscape elements (land cover patches) in this papers were based on following landscape metrics: • NP (Number of patches) -equals the number of land cover patches in each patch type -class.• CA (Class area) -equals the sum of the areas belonging to a given class.Units of equals: quadrate meters (m2).• MPS (Mean patch size) -equals the sums of the area of all land cover patches divided by the number of patches of the same type.Units of equals: quadrate meters (m2).• % (Percentage) -represent ratio of each land cover class.
The classification of land cover patches was based on Corine Land Cover 2006 (CLC2006), that provides consistent information on land cover and land cover changes across Europe.

Results and discussion
Based on previous research of Unger et al. (2011aUnger et al. ( , 2011b) ) and Popov and Savic (2010) there are nine different zones of annual mean UHI temperature intensity in area of Novi Sad (0ºC, +0.5ºC, +1ºC, +1.5ºC, +2ºC, +2.5ºC, +3ºC, +3.5ºC and +4ºC).Evaluation of zones is based on quantification of land cover patches in each zone, and this research is focused on the comparison of artificial surface impacts on each.The main result is land cover patches analyse with highlight on artificial surfaces impact on increasing temperatures in Novi Sad (Figure 1).The zone of 0ºC of UHI intensity occupies 37.11ha, and it is 0.64% of the total urban area (Table 1).This is external zone and the smallest one, with climate conditions the most likely as rural area in Novi Sad surroundings.
Number of patches (NP) in 0ºC zone is 7.That is 3.78% from all patches in research area.That means this zone is moderate fragmented compared with other zones.Total area of artificial surfaces (112,121,141) encompass 36.12% of 0ºC zone.
The area of 0.5ºC zone occupies 661.40ha, that is 11.35% of the total urban area (Table 2).
NP in 0.5ºC zone is 43.That is 23.24% from all patches in research area.That means this zone is extensively fragmented compared with other zones.Total area of artificial surfaces (112,121,141,142,122) encompass 26.76%.Even this is smaller than in the 0ºC zone, the impact of artificial surface is more evidence because there are five artificial surfaces patches.
The area of 1ºC zone occupies 975.40ha, that is 16.74% of the total urban area (Table 3).
NP in 1ºC zone is 44.That is 23.78% from all patches in research area.That means this zone is extensively fragmented compared with other zones.Total area of artificial surfaces (112,121,141,142,122,123) encompass 54.36%.Comparing with previous zone, percentage of area under the artificial surfaces is higher for 27.6% and temperature is higher for 0.5 ºC.
The area of 1.5ºC zone occupies 886.83ha, that is 15.22% of the total area (Table 4).
NP in 1.5ºC zone is 36.That is 19.46% from all patches in research area.That means this zone is extensively fragmented compared with other zones.Total area of artificial surfaces (112,121,141,122,123) encompass  The area of 2ºC zone occupies 852.28ha, that is 14.63% of the total urban area (Table 5).
NP in 2ºC UHI zone is 27.That is 14.59% from all patches in research area.That means this zone is moderate fragmented compared with other zones.Total area of artificial surfaces (112,121,122,123,141) encompass 90.95% of the zone.Comparing with previous zone, percentage of area under the artificial surfaces is higher for 13.48%.
The area of 2.5ºC zone occupies 914.34ha (Table 6), that is 15.69% of the total area.NP in 2.5ºC zone is 12.That is 6.49% from all patches in research area.That means this zone is less fragmented compared with other zones.Total area of artificial surfaces (112,121,122,123) encompass 96.06% of the zone.Comparing with previous zone, percentage of area under the artificial surfaces is higher for 5.11%.
The area of 3ºC zone occupies 705.82ha, that is 12.11% of the total urban area (Table 7).
NP in 3ºC zone is 10.That is 5.41% from all patches in research area.That means this zone is less fragmented compared with other zones.Total area of artificial surfaces (112,121,122,123) encompass 99.98%.Comparing with previous zone, percentage of area under the artificial surfaces is higher for 3.92% and temperature is higher for 0.5 ºC.
The area of 3.5ºC zone occupies 586.71ha, that is 10.07% of the total area (Table 8).
NP in 3.5ºC zone is 5.That is 2.70% from all patches in research area.That means this zone is less fragmented compared with other zones.Total area of ar- Comparing with previous zone, percentage of area under the artificial surfaces is higher for 0.02%.The area of 4ºC zone occupies 206.19ha, that is 3.54% of the total urban area (Table 9).NP in 4ºC zone is 1.That is 0.54% from all patches in research area.That means this zone is less fragmented compared with other zones, i.e. this zone is not fragmented at all.Total area of artificial surfaces (112) encompasses 100%.Comparing with previous zone, percentage of area under the artificial surfaces is the same and temperature is higher for 0.5 ºC.

Conclusion
According to the results of the urban heat island pattern in Novi Sad the main conclusions of this study are as follows: This research examined land cover patches by a set of landscape metrics for area and size and annual mean UHI temperature intensity zones.Evaluation of artificial surface ratio values by temperature zones varies from 26.76% to 100% in densely built-up downtown, and temperatures vary from 0ºC to +4ºC.The impact of artificial surfaces on increasing temperatures is evident, because in almost all zones (except 0.5ºC zone), increasing of percentage of area under the artificial surfaces indicates the increasing temperatures in the same area.Results show that total area of temperature zone is opposite proportional with increasing of temperatures, which indicates that artificial surface impact is more effective in smaller zones.

Figure 1 .
Figure 1.Annual mean UHI temperature intensity and CLC of Novi Sad

Table 1 .
0°C zone of UHI temperature intensity

Table 2 .
0.5°C zone of UHI temperature intensity

Table 3 .
1°C zone of UHI temperature intensity

Table 5 .
2°C zone of UHI temperature intensity

Table 7 .
3°C zone of UHI temperature intensity

Table 8 .
3.5°C zone of UHI temperature intensity

Table 9 .
4°C zone of UHI temperature intensity