Determining the Effect of Green Space Ratio and Urbanization on the Land Surface Temperature, a Case Study in the Istanbul Metropolitan

Studies have shown that the greenspace ratio has a cooling effect on the land surface temperature (LST) in different regions. Sample plots were obtained from 32 different regions in Istanbul. For 1985, 2000, 2013, and 2021, LSTs were determined using Landsat satellite images, and their relationships with GI, NDVI, and NDBI were examined. In the 1985–2021 period, the rate of greenspace in the sample plots decreased from 23 to 6.9%. The lowest LSTs were obtained in 1985, whereas the highest LSTs were found in 2013. Generally, low LSTs values were obtained in areas with a high greenspace ratio. The GI index decreased from 0.23 to 0.07 from 1985–2021. There was an increase of 10.07°C in average LST values in the 1985–2021 period. Negative correlations were found between NDVI and GI indices and LST, and positive correlations were found between NDBI and LST. In 1985, the lowest LST value was obtained in the 31st region with a greenspace ratio of 54%, while in other periods it was 27th region, some of which was covered with forests and the percentage of greenspace ratio decreased from 21 to 11%. The areas with the highest LST values were generally obtained in areas with dense population and urbanization and with a greenspace rate of 1% or less. The DUNCAN test was used to separate regions in terms of LST values.