Exploring the spatial potential of neglected or unmanaged blue spaces in the city of Warsaw, Poland

Urban Blue Spaces are often treated as a part of Urban Green Infrastructure (UGS). However, the recognition of blue infrastructure as a linked but at the same time separate part of the UGS network is important, since water itself has many values while also posing a range of risks. In this study we identified 427 blue spaces within the administrative border of the city of Warsaw, Poland. We characterised these cases from the perspective of users: their connection, interaction and potential use of the water bodies. Based on a cluster analysis (using PCA and k-mean methods) we distinguished three main clusters of water bodies and from this we created a typology of Warsaw urban water, especially focusing on the importance and potential of abandoned, forgotten and unmanaged (invisible) urban blue spaces. We conclude that the recognition of types and patterns of blue areas in the city provides a good basis for city and local level design decisions for maximising the potential for human-water interactions. This knowledge enhances the potential of the integrated UGS which should be re-named as Urban Blue-Green Infrastructure in order to recognise the particular role of water.