Page 132 - Çevre Şehir İklim İngilizce - Sayı 1

Urban Cold Space Cooling Capacity

Discussion

1. The Importance of Vegetation in Mitigating the Effects of Urban
Heat Islands

The results of the study show that as the NDVI value increases, temperature
(A_LST) decreases. Similar results were found in previous studies, but this
study concludes that a relatively high correlation coefficient was measured
between LST and NDVI (Amiri et al, 2009, Carlson and Arthur, 2000, Hung et
al, 2006, Kuşçu Şimşek and Şengezer, 2012, Mackey et al, 2012, Marando et al,
2019, Yuan and Bauer, 2007; Tiangco et al, 2008; Weng and Lu, 2008). There is
a very weak correlation in the negative direction between total tree covered
surface area (T_T) and total grass covered patch in square meter (GRASS_T),
and LST, which are variables referring to the presence of vegetation. In the
literature against these arguments, there is a strong correlation between the
proportion of tree-covered surface areas, which refers to the presence of trees
(Maimaitiyiming et al, 2014, Ren et al, 2013) and the variables of total tree-
covered surface areas, and LST (Kong et al, 2014).

The results of the study show that the spatial formation of trees and grass
is more important in accounting for temperature increases compared to the
presence of trees and grass. These findings are similar to the results of previous
studies (Zhou et al, 2017). According to the results, GRASS_N and T_N have
been the variables that affect temperatures in terms of the presence of green
spaces. This result is in line with the results of previous studies (Maimaitiyiming
et al, 2014). The increase in the number of tree and grass covered patches
means that the green spaces are present in smaller patches in urban cool
areas, but arranged in different locations within a place, and thus displays
spatial continuity. The increase in the number of patches shows that the total
green area perimeter has increased, which decreases temperature further
along with the increase in the interaction surfaces between urban areas and
green areas (Cao et al, 2010, Maimaitiyiming et al, 2014, Li et al, 2017, Zhang
et al, 2016). However, the increase in the number of patches regarding the
presence of vegetation has caused an increase in the maximum (Max_LST)
and standard deviation (SD_LST) values of temperatures. This may result from
the increase in the number of patches and the increase of temperatures due
to the increase in decrepitation and the reduction of spaces. However, due
to decrepitation, the cooling effect of each patch decreases, which increases
its perimeter as well as temperature difference. Thus, LST standard deviation
value may increase. (Table 4).

Year 1 / Issue 1 / Jan 2022 117