Blue infrastructure is not only an element related to rainwater retention in a city but also a factor shaping urban space. As a result of the impact of blue infrastructure on form, function and character of urban space, a unique space is created – an urban blue space. The subject of the article is associated with the blue infrastructure on shape and character of urban spaces, as well as water-land spatial relations within urban blue space. Author of the article analised spatial relations occurring in port cities between aquatic and terrestrial space from perspective of the land, but also water, which is an equally important part of city’s area. As a result models of two-dimensional water-land relations have been recognised and described.

Rapid urban development in the second half of the 20th century led to increasingly urbanized structures. As a result, industrial areas that were previously located on the periphery have found themselves in the inner city areas, contributing to the deterioration of the environmental quality and the attractiveness of these areas. Their closure requires the revitalization of decayed areas. The aim of this paper is to present parks built in post-industrial areas in the context of the need to preserve the post-industrial heritage and place-based identity, and to improve the environmental and climatic values of cities. The study’s methodology consists of literature studies, in-situ field research and the use of geo-information systems. Based on an analysis and a detailed comparative study of selected projects carried out in Paris, Barcelona and Turin over the last forty years, the authors demonstrated that brownfield sites are transformed into green parks for leisure and recreation, forming part of the green-blue infrastructure of cities. They improve the environmental conditions of congested city centres, which is particularly important in the face of rapid climate change. The use of decayed brownfield sites for the redevelopment of high and medium-height greenery can help to reduce the urban heat island effect and air pollution. The struggle for a clean environment can be fought using natural structures, with greenery in parks and gardens becoming a tool for improving the climate and increasing urban water retention.