Development of an urban green space indicator and the public health rationale

Aims: In this study, the aim was to develop and test an urban green space indicator for public health, as proposed by the World Health Organisation (WHO) Regional Office for Europe, in order to support health and environmental policies. Methods: We defined the indicator of green space accessibility as a proportion of an urban population living within a certain distance from a green space boundary. We developed a Geographic Information System (GIS)-based method and tested it in three case studies in Malmo, Sweden; Kaunas, Lithuania; and Utrecht, The Netherlands. Land use data in GIS from the Urban Atlas were combined with population data. Various population data formats, maximum distances to green spaces, minimum sizes of green spaces, and different definitions of green spaces were studied or discussed. Results: Our results demonstrated that with increasing size of green space and decreased distance to green space, the indicator value decreased. As compared to Malmo and Utrecht, a relatively bigger proportion of the Kaunas population had access to large green spaces, at both shorter and longer distances. Our results also showed that applying the method of spatially aggregated population data was an acceptable alternative to using individual data. Conclusions: Based on reviewing the literature and the case studies, a 300 m maximum linear distance to the boundary of urban green spaces of a minimum size of 1 hectare are recommended as the default options for the indicator. The indicator can serve as a proxy measure for assessing public accessibility to urban green spaces, to provide comparable data across Europe and stimulate policy actions that recognise the importance of green spaces for sustainable public health.