Md. Hasanur Rahman

and 2 more

Dhaka is the capital and largest city of Bangladesh; it is the world's seventh most densely populated city and is often regarded as the world's most densely populated built-up urban region. This city has experienced a significant increase in the urban heat island (UHI) effect, and temperatures are currently several degrees higher than in the surrounding urban areas. The existing UHI-based studies in the context of Dhaka city have still not addressed the statistical relationship between UHI and several indicators (individually), such as water availability, air quality, and vegetation index. This study intends to investigate urban heat patterns and their associated changes by developing UHI maps from 2013 to 2023. To generate the maps, we are evaluating UHI using land surface temperature (LST) data extracted from USGS Landsat 8 OLI images. The first objective of this study is to examine the temporal evolution of urban heat in Dhaka using the developed UHI map to identify trends, patterns, and hotspots. The second objective is to explore the relationship between air quality, urban heat, water availability, and vegetation index of Dhaka city. The findings of this study show that due to UHI, urban heat increased by nearly 6°C in Dhaka city. This study also found that NO2 (Nitrogen Dioxide) and O3 (Ozone) have positive correlations with Dhaka's UHI, whereas NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index) have negative correlations. The study will be insightful for sustainable urban planning and environmental management by better understanding the above-mentioned complex relationship and help to develop an enhanced understanding of Dhaka's urban heat dynamics and their influence on water availability and air quality. Additionally, the outcomes will be helpful for policymakers to increase resilience to minimize the adverse effect of UHI in quickly rising cities like Dhaka.