The interplay between urbanization, vegetation loss and surface heat island in cities: two decadal empirical evidence from Pakistan

Urbanization frequently results in a rise in impervious surfaces, reducing the vegetation cover and subsequently impacting urban surroundings. This study examines the correlation between changes in vegetation cover (Delta EVI) and variations in land surface temperature (LST) to assess the intensity of the Surface Urban Heat Island Intensity (SUHII) in nine major cities of Pakistan over two decades (2001-2020). Remotely sensed data from MODIS satellite were used to analyze the spatio-temporal trends and relationship of Delta EVI and SUHII. The Mann-Kendall trend test revealed statistically significant declining trends in Delta EVI, with the most noticeable decreases occurring during Autumn (-0.00224 yr- 1). In contrast, SUHII exhibited a significant rise, particularly during the spring season (0.041 degrees C yr- 1) and winter season (0.005 degrees C yr- 1). The Pearson correlation and continuous wavelet coherence have established a statistically significant inverse relation between Delta EVI and SUHII in all seasons except for winter. These findings emphasize the immediate requirement for geospatial monitoring and efficient measures to improve urban sustainability and reduce the impact of heat islands. This study offers crucial insights for formulating methods to guarantee urban comfort and sustainability in the face of rising urbanization. It is recommended that urban planning initiatives prioritize the expansion and preservation of green spaces and implement climate mitigation strategies, such as increasing vegetation cover and using reflective materials in urban infrastructure, to combat the adverse effects of urban heat islands effectively.