Increased access to nearby green-blue areas associated with greater metropolitan population well-being

Numerous cities in the world have to handle and support increasing populations, with questions remaining concerning good planning strategies for their growth and development. Among these questions, access to nature for urban residents has been the subject of increased scrutiny in recent years. We here propose and apply a generally applicable new approach to quantitatively investigate the role of close access to natural or nature-based green-blue areas for the well-being of urban populations. A key novel aspect of this approach is to use income level as a measure of people's ability to choose their nearby living environment such that it provides them with the highest affordable level of well-being. Based on this measure, we concretely investigate possible trends in local green-blue area access with increasing local income level in the case-study example of the Stockholm Metropolitan region in Sweden. For this regional case, we find clear relationships between income level (and related degree of nationality homogeneity) and share of natural/nature-based green-blue areas and man-made grey areas within walksheds of different population segments. The results point at the importance of maintaining and restoring nearby natural and nature-based green-blue areas as key solutions for increased well-being of urban populations and call for further testing and comparative investigations of local-scale associations between socio-economic descriptors and physical environment in other parts of the world.