Mapping the intersection of social deprivation and air pollution in London: Identifying domestic garden types

Domestic gardens are widely recognised as a form of green infrastructure (GI) that positively impacts mental health and well-being, but little is known about their local impact on air quality and temperature regulation. Domestic gardens can comprise a significant proportion of GI in cities, yet trends in the UK indicate many planted gardens have been lost to paving. Urban communities could therefore be missing out the numerous benefits 'green' gardens can provide. Especially vulnerable populations live in polluted areas, often home to lower-income communities and marginalised groups with fewer resources to move to less polluted areas. This research to create a map of London neighbourhoods where social deprivation and high levels of air pollution overlap, identifying the type of gardens existing in these areas. Using a geographical information system approach, London neighbourhoods were identified where social deprivation and high levels of air pollution overlap. Using Social Deprivation Index and air quality datasets from the London Atmospheric Emissions Inventory from 2019, a map of London was created. Once the map was created, visual inspection was conducted through Google Streetview and then ground truth by field visits to identify different domestic gardens. Then, streets with domestic gardens that met the following experimental design criteria: open, grey barrier, and vegetated barrier were identified to test the hypothesis ‘vegetated barriers can reduce pollution/temperature in gardens near busy roads’. The mapping exercise provided new insights on hotpots in London of poor air quality and high social deprivation. The findings highlight the prevalence of paved gardens, reducing the potential benefits that vegetated gardens could provide in urban environments. The map shows where efforts should be focused to increase green infrastructure and where welldesigned residential gardens could have the greatest impact on the most vulnerable population. This information could help local authorities and stakeholders in identifying priority areas for green infrastructure.