Integrated green grey infrastructure (IGGI) - Green screen guard rail.

Area characterisation: 

The A38 Bristol Street in in central Birmingham is a busy thoroughfare with heavy traffic - private, commercial and public vehicles. It is a densely urbanised area with little permeable surface. Opportunities for greening were limited to a central reservation.

Objective: 

Air quality in urban areas is a known issue for health and quality of life. Motorised vehicles produce a range of pollutants that can affect human health. These include very small particles emitted from exhaust (especially from diesel-fuelled vehicles), and from wear-and-tear on brakes and tyres. If inhaled these particles can cause a range of both short-term and more chronic health problems, including increased chances of death from respiratory and cardiovascular disease. This Particulate Matter (PM) is measured in microns (one micron is one millionth of a metre). Health concerns start with particulates of 10 microns (PM10) in diameter or finer, where the smaller the size (e.g. PM2.5), the greater the health risk. Some plants can provide amelioration to some of these effects by capturing PMs but little is known about how this can best be exploited for practical application. The Constructor was looking for a site to conduct some research on this topic and recruited support from a local University and business development group.

Actions: 

Installation of pre-grown plants, hand-wound on Mobilane.co.uk mesh panels, in biodegradable pots and growing medium. In this case study they are attached to pre-installed rails beside a busy city centre dual carriageway in central Birmingham, providing an instant green screen to improve the aesthetic of the area and provide some air pollution reduction. The same techniques can also be used in residential and industrial areas on a range of support structures, including purpose built options, with this supplier offering a choice of around a dozen different plant species and screens in a number of sizes.

Potential impacts/benefits: 

Analysis of the leaves of the screen compared to those from a control site shows the capacity to remove pollutants. For relatively little cost this could provide major benefits by reducing local exposure to airborne particulates linked to acute and chronic health issues. Alongside monitoring of impacts on local pollution, this installation was partly an attempt was improve the aesthetic of the area and the economic prosperity of the local businesses as the vegetative element also improves the aesthetic of heavily urbanised areas.In addition, certain species can be important for biodiversity,for example, ivy can be important as a source of cover for birds and, where allowed to flower, provides a valuable nectar source in urban areas for pollinating insects, and berries forbids in winter.

NbS benefits 
  • Developing climate change adaptation; improving risk management and resilience
  • Flood peak reduction
  • Increasing infiltration
  • Reduce flood risk
  • Reduce load to sewer system
  • Reduce run-off
  • Reducing temperature at meso or micro scale
  • Developing climate change mitigation
  • Carbon sequestration and storage
  • More energy efficient buildings
  • Restoring ecosystems and their functions
  • Greater ecological connectivity across urban regenerated sites
  • Improve connectivity and functionality of green and blue infrastructures
  • Increase achievements of biodiversity targets
  • Increase Biodiversity
  • Increase quality and quantity of green and blue infrastructures
  • Enhancing sustainable urbanisation
  • Changing image of the urban environment
  • Creation of green jobs relating to construction & maintenance of NBS
  • Improve air quality
  • Improve water quality
  • Increase amount of green open spaces for residents
  • Increase awareness of NBS solution & their effectiveness and co benefits
  • Increase communities’ sense of ownership
  • Increase population & infrastructures protected by NBS
  • Increase stakeholder awareness & knowledge about NBS
  • Increase well-being
  • Increase willingness to invest in NBS
  • Provision of health benefits
  • Reducing wind speed
  • Social learning about location & importance of NBS
Transferability of the result: 

Pedestrian guardrails have been very widely used across the UK road network. Not all would be suitable for incorporating this technique, but there is widespread potential to apply this across the UK. The example here illustrates retrofitting to existing rail boundaries; for new build projects it is conceivable that a built-in solution may be possible that negates the need to combine the two elements of a green screen with support and guardrail, fencing or wall. Combining the greening into the support during the design phase would likely reduce the costs of installation. Similarly, where crash protection function is not required, the screens can be installed with post supports without guardrails.

Screen slike these present a relatively low cost method to address some of the harmful and costly issues associated with urban air pollution, climate change and urbanisation.

Lessons learned: 

Analysis of the leaves of the screen compared to those from a control site shows the capacity to remove pollutants. This could provide major benefits by reducing local exposure to airborne particulates linked to acute and chronic health issues, at relatively low cost. Vegetation also improves the aesthetic of heavily urbanised areas Alongside monitoring of impacts on local pollution this installation was partly an attempt was improve the aesthetic of the area and the economic prosperity of the local businesses. Ivy can be important for biodiversity as a source of cover for birds and, where allowed to flower, provides a valuable nectar source in urban areas for pollinating insects, and berries forbids in winter.

NbS classification 
  • On Building and Structures
  • Eco managment plan
  • Eco management plans