Improving urban design to address human thermal discomfort in urban agglomerations characterized by different microclimatic conditions

The Urban Heat Island (UHI) phenomenon has become a significant concern in urban areas worldwide as urbanization continues to intensify. This process leads to notable changes in microclimates within cities, resulting in higher temperatures compared to their surrounding rural areas. Referred to as the Urban Heat Island effect, this phenomenon is mainly caused by human activities such as industrialization, transportation, and construction, which alter land surfaces and increase heat retention.

Identifying hot spots within cities necessitates a thorough understanding of various contributing factors, including land use patterns, building density, surface materials, and the distribution of green spaces. ENVImet modeling facilitates this understanding by allowing precise simulation of microclimates, enabling researchers and planners to pinpoint areas with elevated temperatures and analyze their underlying causes. Once hot spots are identified, ENVImet plays a crucial role in devising optimized mitigation scenarios. By simulating interventions like increasing green space coverage, implementing cool roofs and pavements, optimizing urban layouts for improved airflow, and integrating water bodies, ENVImet enables stakeholders to assess the effectiveness of each strategy in reducing temperatures and mitigating UHI effects.

The objective of this study is to optimize the urban design of established infrastructure within cities experiencing different microclimatic conditions, such as Aspropyrgos in the greater Athens area and Tripolis in central Peloponnese, Greece. We conduct urban design simulations by:

i) Increasing green spaces to absorb heat, provide shade, and promote evapotranspiration, thereby reducing surface temperatures and mitigating UHI effects.

ii) Implementing shading structures and urban canopies to offer shelter from direct sunlight.

iii) Integrating water features to assess the effectiveness of incorporating water bodies like ponds, lakes, and fountains in the studied urban environments. Water features act as natural heat sinks, dissipating excess heat through evaporation and creating cooling microclimates.

Furthermore, the model's optimization capabilities allow for fine-tuning these scenarios to achieve the best outcomes. By iteratively adjusting parameters and variables, planners can tailor mitigation strategies to specific urban contexts, considering factors such as local climate, population density, and infrastructure constraints. Optimizing mitigation scenarios for UHI hot spots represents a proactive approach toward enhancing urban resilience and sustainability. By leveraging simulation and optimization, cities can develop targeted interventions that mitigate heat-related risks and foster more livable and resilient urban environments for current and future generations.