Publications

Khan, N; Shahid, S (2024). Urban heat island effect and its drivers in large cities of Pakistan. THEORETICAL AND APPLIED CLIMATOLOGY.

Abstract
This study assessed the urban heat island (UHI) effect and its driver in five major cities of Pakistan from 2001 to 2022 using Moderate Resolution Imaging Spectroradiometer (MODIS) daily diurnal land surface temperature (LST) data. The study also used the City Clustering Algorithm (CCA) and yearly land cover data from MODIS to quantify the growth of urban areas and statistical data to estimate the changes in population density. The results showed a temperature difference of 4.1 - 5.0 degrees C at night and 2.9 - 4.1 degrees C during the day between the city area and outskirts. More regions showed a significant temperature rise during the nighttime, with an LST increase of more than 0.15 degrees C/year. Major cities of Pakistan have expanded more, ranging from 1.5 to 5.87%, than the population growth (51.6 to 125.5%), which caused a rapid increase in urban population density. This study found a strong correlation between population density and LST, ranging from 0.68 to 0.84 for nighttime LST and from 0.60 to 0.78 for daytime LST. The analysis of changes in urban built-up areas revealed an increase in population density by nearly threefold in some cities. This suggests that dense urbanization is the main factor behind the rapid rise in the UHI effect. Global temperature rise coupled with increased population density would cause a continuous increase in UHI in mega cities of Pakistan. Unless effective mitigation measures are implemented, it will lead to a notable rise in public health risks, water and energy consumption, and damage to urban ecosystems.

DOI:
10.1007/s00704-024-04959-x

ISSN:
1434-4483