Using green infrastructure as a social equity approach to reduce flood risks and address climate change impacts: A comparison of performance between cities and towns

Abstract

Green infrastructure is a promising strategy aiming to address climate change impacts and associated flood risks, as well as bringing social equity benefits such as increased access to greenspace in urban areas. However, not only does it take up valuable development space, but the effectiveness of differing green infrastructure types in alleviating extreme rainfall impacts is unclear. This paper develops and tests scenarios linking various rainfall intensities (historical, RCP4.5 and RCP8.5), types of green infrastructure (bio-retention cells, permeable pavement and rain gardens), and different spatial distributions (5 % and 10 % of the sub-catchment area) to investigate the extent to which green infrastructure can most effectively minimise flood risks while providing targeted equity benefits. Findings indicate that the implementation of 10 % of green infrastructure could reduce runoff peak rate and total runoff volume around 50–75 % at the sub-catchment scale. The paper provides two contributions. First, we develop and test a methodological approach that is able to link green infrastructure to climate and spatial futures. Second, we demonstrate which types of green infrastructure, and in which combinations, can most effectively reduce the impact of extreme weather events. Findings suggest that the strategic implementation of small green infrastructure areas can be hugely effective, particularly if multiple measures are combined.