Manchester : the role of urban domestic gardens in climate adaptation and resilience

Urban green infrastructure (GI) is a well-known solution to enhance resilience to climate hazards, particularly through the climate regulating functions of green spaces including cooling the city and moderating runoff, in addition to improving health and wellbeing. Domestic gardens provide a valuable contribution to the larger GI network in cities, however, there is less detailed knowledge about these areas and their role in urban climate regulation, in comparison to publicly accessible spaces such as parks. Environmental models require detailed information relating to GI type, structure, and height, since the functionality of different GI types (e.g. mown grass, rough grass, shrubs, trees) is variable in its influence upon urban microclimate. Whilst remote sensing classification techniques can distinguish broad vegetated and non-vegetated classes, they cannot identify the diverse range of surface types within gardens. This chapter presents a novel approach to collecting fine-scale high quality information on urban domestic gardens to produce new climate information for planning healthy cities, within the case study city of Manchester, UK. The approach combines citizen science data with high resolution areal imagery and environmental modelling, to quantify and map cooling potential and runoff attenuation under different scenarios. This found that greening gardens could be the solution to reducing future risk of heat wave events and surface water flooding, particularly in neighbourhoods with a high proportion of gardens. This new climate information was presented in an action plan, co-developed with project partner organisations, embedded within the existing policy framework. Engagement of citizens directly led to positive climate resilient actions within Manchester as residents pledged and implemented climate adaptation solutions within their gardens, such as replacing impervious surfaces with vegetation. This project demonstrates how cross-disciplinary collaboration among scientists, planners, government, non-governmental organizations, the private sector and the general public helps to address the challenges that lie ahead for cities as healthy environments