Impact of Urbanization on Urban Climate: A GIS and Remote Sensing Approach on Dhaka City (2000-2025)

Abstract

Unplanned and swift urbanization from 2000-2025 has changed Dhaka’s land use and climate significantly. GIS and remote sensing were utilized in this thesis to quantify land cover change and the impact of the urban heat island (UHI) effect in Dhaka City. Four land cover categories (Built-up, Vegetation, Open Land, Water,) were classified through using multi-date Landsat satellite images (2000, 2010, 2020, 2025) to assess spatiotemporal transformations. To retrieve land surface temperatures (LST) for each period, thermal infrared data were processed which enabled analysis of how urban expansion affects and increases heating of the surface. Methodology included change detection, supervised classification, and LST retrieval, validated with field data and literature. Findings of a sharp increase in built-up area (from 29% to 41% of the area) and loss of vegetated land (from 28% to 11%) between 2000 and 2025 were recorded. Higher mean and maximum LST in urbanized zones were correlated with these land cover shifts, emphasizing the increasing UHI effect. Hottest surfaces were discovered in developed bare lands recently and also in dense urban areas. Water bodies and green spaces remained cooler on average. Some irregularity in LST patterns were observed due to seasonal differences in image acquisition, highlighting the need for interpretation cautiously. Dhaka’s urban expansion has led to greater heat retention and spatially increased UHI hotspots according to the findings of this research. Academic contributions of this thesis was by exploring updated, spatially explicit evidence of relation between land cover change and urban climate in Dhaka. These insights are significant for urban environmental management, illustrating the critical importance of sustainable planning interventions (e.g. preserving green infrastructure) to mitigate rising urban heat and improve livability in megacities like Dhaka.