Page - 399 - in Biodiversity and Health in the Face of Climate Change

399 Mayer et  al. (2012) explored whether voluntary incentives were effective at dis- tributing storm water management throughout a small suburban catchment, and whether the number and placement of rain gardens and rain barrels were sufficient to alter the hydrology, water quality and aquatic biology of the catchment. In total, 83 rain gardens and 176 rain barrels were installed onto more than 30% of the 350 eligible residential properties in a 1.8  km2 catchment area in Ohio, USA.  The inter- vention had an overall small but statistically significant effect of decreasing storm water quantity at the sub-watershed scale. In a similar study in the same area (Shuster and Rhea 2013; Roy et  al. 2014), the installation of 81 rain gardens and 165 rain barrels at four experimental areas was compared to two control areas. In contrast, Case Study: Bristol Street Green Screens, Birmingham, England, UK Bristol Street in Birmingham is a dual carriageway with a wide grassed cen- tral reservation along which runs, almost continuously, a metal highway pedestrian guardrail. This greening intervention involved fitting green vege- tated screens to 141  m of existing guardrail. Installation of the green screens was completed in 2015 costing approximately €29,000. Follow-up analysis of particulate matter (PM10, PM2.5 and PM1) 2 months post installation showed significant increases (p  <  .001) of particulates on green screen leaves in com- parison to nursery stock of the same plants. In addition to the potential air quality improvement role of the green screens, they also improve the aesthet- ics of the street and may benefit local businesses through increased pedestrian traffic. The green screens require minimal maintenance and through utilizing existing infrastructure may provide a cost-efficient and practical solution to increasing green space within dense urban areas (Fig.  17.3). Fig. 17.3 The left panel shows Bristol Street, Birmingham in 2014 before green screen implementation and the right panel shows the street in 2016 after green screen implementa- tion as part of the Bristol Street Green Screens Trial Project, Birmingham, UK. (Image: Chris Rance) 17 Environmental, Health and  Equity Effects of  Urban Green Space Interventions