Green infrastructure: The future of urban flood risk management?

Abstract

Urban flooding is a key global challenge which is expected to become exacerbated under global change due to more intense rainfall and flashier runoff regimes over increasingly urban landscapes. Consequently, many cities are rethinking their approach to flood risk management by using green infrastructure (GI) solutions to reverse the legacy of hard engineering flood management approaches. The aim of GI is to attenuate, restore, and recreate a more natural flood response, bringing hydrological responses closer to pre‐urbanized conditions. However, GI effectiveness is often difficult to determine, and depends on both the magnitude of storm events and the spatial scale of GI infrastructure. Monitoring of the successes and failures of GI schemes is not routinely conducted. Thus, it can be difficult to determine whether GI provides a sustainable solution to manage urban flooding. This article provides an international perspective on the current use of GI for urban flood mitigation and the solutions it offers in light of current and future challenges. An increasing body of literature further suggests that GI can be optimized alongside gray infrastructure to provide a holistic solution that delivers multiple co‐benefits to the environment and society, while increasing flood resilience. GI will have to work synergistically with existing and upgraded gray infrastructure if urban flood risk is to be managed in a futureproof manner. Here, we discuss a series of priorities and challenges that must be overcome to enable integration of GI into existing stormwater management frameworks that effectively manage flood risk. This article is categorized under: Engineering Water > Sustainable Engineering of Water Engineering Water > Planning Water Science of Water > Water Extremes

Analysis of the influence of urban spatial and green infrastructure on flood adaptation

“…Although definitions of green infrastructure vary considerably (Bartesaghi et al 2017), generally green infrastructure refers to the use of nature to protect, restore, and mimic the natural water cycle of floodplains, rivers, and coasts to manage flood risk effectively (Kattel et al 2021). Green infrastructure fits the broader generic term of nature-based solutions and is an approach to water management that regenerates the natural water cycles, preserving the natural ecosystem while reducing the risk of surface water overflow (Green et al 2021). The use of green infrastructure as a complementary method of urban flood risk management along with traditional gray infrastructure is increasingly recognized in many international cities (Lennon et al 2014;O'Donnell and Thorne 2021).…”

“…Green infrastructure fits the broader generic term of nature-based solutions and is an approach to water management that regenerates the natural water cycles, preserving the natural ecosystem while reducing the risk of surface water overflow (Green et al 2021). The use of green infrastructure as a complementary method of urban flood risk management along with traditional gray infrastructure is increasingly recognized in many international cities (Lennon et al 2014;O'Donnell and Thorne 2021). Its effectiveness has been studied for a long time, but few studies have quantified its hydrological performance.…”

“…Proper green infrastructure design and implementation will enable broader and more sustainable flood risk strategies in urban areas (Fenner 2017;Ghofrani et al 2020). Green infrastructure provides a sustainable and realistic approach to addressing uncertain flood events by designing systems to operate using natural processes rather than trying to control rainfall runoff unnaturally (Green et al 2021). Additionally, it Urban parks, a part of green infrastructure, play an important role as measures to control urban floods caused by heavy rain (Miguez 2017).…”

“…The impact of urbanization and global warming on flooding will increase in the future as urbanization progresses to accommodate urban population growth and greenhouse gas emissions increase (IPCC 2013). Urban flooding is a major global challenge that is expected to be exacerbated in the future by the intensification of extreme climates, land use changes (e.g., extensive urbanization and reduction of permeable green space), and outdated major infrastructure (Green et al 2021).…”

“…Urban spatial factors (land use and green infrastructure) are a key component of a progressive global management strategy in achieving this goal. Urban spaces must be designed in a way that manages water and improves the environment and society while adapting to the growing threat of urban flooding (Green et al 2021). In particular, urban green space is an important component in promoting resilience to climate change (Reynolds et al 2020).…”