Why Dhaka city has become a 'heat island'

Dhaka city

The recent surge in temperatures gripping Dhaka has sparked widespread concern and curiosity among residents, leading many to question the underlying causes behind this unprecedented heat wave. While the impact of global warming cannot be discounted, experts highlight another crucial factor exacerbating the situation: urban warming, also known as the 'Urban Heat Island' effect.

As temperatures soar above 40 degrees Celsius, it's evident that Dhaka is experiencing the dual brunt of global climate change and localized urban heat buildup. The Meteorological Department's warnings of prolonged heat waves only underscore the urgency of addressing these issues.

Urbanists and engineers delve into the complexities of urban heat islands, emphasizing the pivotal role of local regulations and urban planning in mitigating heat-related risks. The transition from rural landscapes rich in vegetation to concrete-laden urban sprawls significantly alters heat dynamics, leading to temperature differentials of up to 10 to 15 degrees Celsius between cities and rural areas.

Central to the phenomenon of urban heat islands is the replacement of natural land cover with impermeable surfaces such as concrete, asphalt, and brick. These structures absorb and retain heat, contributing to elevated temperatures within cities. Dhaka, in particular, grapples with a glaring deficit of green spaces, with only 8 percent allocated on paper, far below the recommended 20 to 25 percent.

Wetlands, often overlooked but crucial in temperature regulation, are conspicuously absent in Dhaka's urban landscape. Unlike areas like Cox's Bazar, where the presence of water bodies helps temper extreme temperatures, Dhaka's wetlands have been encroached upon, further exacerbating heat-related challenges.

The failure to enforce regulations mandating open spaces in urban development projects perpetuates the decline of natural land cover. Instead of lush greenery, these designated areas often accommodate car garages or auxiliary structures, exacerbating urban heat island effects.

As Dhaka grapples with the ramifications of unchecked urbanization and climate change, it becomes imperative to adopt holistic strategies that prioritize green infrastructure, preserve wetlands, and enforce stringent urban planning regulations. Failure to address these underlying issues not only amplifies the risk of heat-related illnesses but also jeopardizes the city's long-term sustainability and resilience in the face of climate uncertainty.