Blue and Green Infrastructures: A Dual Solution for Urban Heat Island Effects and Urban Flooding

This review critically examines the interplay between green and blue infrastructures, urban heat island (UHI) effects, and urban flooding. Urban Heat Island (UHI) and increased flood risk are co-located due to common factors like impermeable, heat-absorbing surfaces. By synthesizing recent findings from 2009 to 2024, we explore how using green and blue infrastructures mitigating UHI and urban flood events. We delve into the characteristics and effectiveness of various green and blue infrastructure solutions, including green roofs, bioswales, and wetlands. The analysis reveals that UHI significantly exacerbates urban flooding disasters. Despite advancements in understanding the effect of blue and green infrastructures, significant gaps remain in the literature. Notably, long-term impact assessments and comprehensive evaluations of existing mitigation strategies are scarce. Future investigative pursuits should integrate the simultaneous ramifications of Urban Heat Islands and urban flooding to proficiently inform urban planning strategies. The review emphasizes the importance of interdisciplinary approaches, integrating hydrology, climatology, urban planning, and technology. Moreover, this review systematically examines green and blue infrastructure separately in different sections, detailing their respective influences on urban heat island and flooding, with a focus on specific mechanisms such as reduced runoff velocity and evaporative cooling. While historically, BGI projects may have focused on single objectives, there's a growing trend towards designing BGI for multiple benefits. By consolidating existing research, this review serves as a valuable resource for researchers and policymakers, enriching the current body of knowledge and providing clear directions for future investigations in urban disaster management.