Improving urban sustainability through microscale configuration of green infrastructure

With rapid urbanization and population expansion, the urban microclimate is becoming one of the most important determinants of urban sustainability. Uncontrolled urban growth often leads to land use and land cover changes, intensifying urban heat, altering wind patterns, and causing seasonal microclimatic variations. These changes reduce human comfort, increase cooling loads and elevate energy consumption, thus making cities major contributors to climate change. To address these challenges, the adoption of sustainable practices is essential. Green Infrastructure (GI) is one such potential strategy. However, its efficacy is highly dependent on spatial distribution, coverage ratio, seasonality and building configuration, which makes it necessary to consider at the neighbourhood scale. This study employs Computational Fluid Dynamics to assess the year-round impact of GI on microclimate regulations in a prototypical urban neighbourhood in hot-arid climatic conditions of Ahmedabad, India. It also involves investigating the effects of GI on annual energy consumption and carbon dioxide emissions. The study also introduced the comfort energy performance index (CEPI) to holistically assess performance to determine the influence of different spatial distributions and coverage ratios on an urban domain. The results reported that implementing GI led to variations in air temperature, energy consumption, and carbon dioxide emissions, ranging from approximately -4 to +1 C, -30 to +4 %, and -25 to +5 %, respectively. These findings emphasize the importance of strategic GI placement, as improper configuration of GI can lead to limited or even adverse effects. Ultimately, the insights from this study can inform urban planners and policymakers, providing a pathway to mitigate urban heat, lower energy consumption, and address climate change through GI interventions.