Urban blue and green spaces: distribution, social equity, and ecological implications in Great Britain

Cities are closely linked to the ‘triple planetary crisis’, climate change, pollution, and biodiversity loss, and urbanisation affects human physical and psychological health. Urban blue-green spaces can lessen impacts by regulating temperature and water, purifying air, and supporting biodiversity, but research remains focused on green spaces. We investigate blue space cover across 500 towns and cities in Great Britain by including high-resolution blue spaces into existing land cover maps. We then assessed how blue and green cover, and land-cover diversity vary across socioeconomic deprivation gradients. Blue space covers less area than green space but is more evenly distributed across socioeconomic gradients. Higher land-cover diversity in deprived areas suggests urban regeneration may contribute to habitat homogenisation. These findings provide the first nationwide comparison of blue space cover, providing a holistic assessment of their ecosystem service distribution. In addition, we highlight the social relevance of overall land-cover diversity for sustainable urban development.