Analysing the Impact of Microclimatic Variation on Urban Residential Environment: A Study of Dhaka City

Abstract

Rapid and unplanned urbanization in Dhaka has led to diverse microclimatic conditions across its residential neighbourhoods, with significant implications for thermal comfort, public health, and community resilience. This study investigates the impact of microclimatic variation on thermal comfort, health outcomes, and resilience capacity across three contrasting residential typologies in Dhaka: the planned neighbourhood of Dhanmondi, the dense mixed-use area of Chawkbazar, and the informal settlement of Korail Slum. Field-based micrometeorological measurements of air temperature, relative humidity, and wind speed were conducted across all three areas during April to June, supplemented by structured resident questionnaire surveys, Key Informant Interviews, and a Thermal Resilience Index. Thermal comfort was assessed through both objective indices, including Predicted Mean Vote (PMV) and Physiological Equivalent Temperature (PET), and a Subjective Thermal Comfort Index (STCI) derived from resident surveys. Outdoor mean temperatures ranged from 32.41°C in Korail to 33.19°C in Chawkbazar, while mean outdoor air speeds varied from 0.0816 ms⁻¹ in Chawkbazar to 0.75 ms⁻¹ in Dhanmondi, indicating that ventilation restriction is a more significant determinant of thermal discomfort than temperature alone in the denser areas. Chawkbazar recorded the highest mean PET of 42.64°C, classified as "Very Hot," while Korail recorded the highest subjective thermal discomfort with an STCI of 7. Thermal Resilience Index scores of approximately 13, 9, and 4 for Dhanmondi, Chawkbazar, and Korail respectively reveal a substantial resilience gap rooted in disparities in energy access, housing quality, and adaptive capacity rather than climatic exposure alone. Residents of Korail further reported perceived associations between thermal conditions and elevated rates of respiratory illness, dermatological infections, and heat exhaustion among children and the elderly. The findings indicate that thermal vulnerability in Dhaka is structurally determined, with informal settlements bearing the compounded burden of the most demanding thermal environments and the weakest capacity to cope with them. The findings provide empirical evidence to support urban heat adaptation planning in rapidly urbanising megacities of the Global South.

The Dhaka University Journal of Earth and Environmental Sciences, Vol. 15(1), 2026, P 27-45