Networks and Fragments: An Integrative Approach for Planning Urban Green Infrastructures in Dense Urban Areas

The reintroduction of natural components into the urban environment has several benefits for the adaptation of urban environments. The urban green infrastructure (UGI) approach makes it possible to develop greening programs on a sound scientific basis and in connection with the ability to provide ecosystem services. However, in practice, UGI programs are almost exclusively based on the concept of a continuous green network, which requires large-scale interventions such as green corridors and parks. This severely limits the extension of UGI in dense urban areas such as historic centers. This article introduces the concept of green fragments and proposes an integrative approach to support greater spatial flexibility of the UGI. By setting appropriate limits on the number and proximity of green fragments, the resulting green system keeps functional connectivity despite being physically discontinuous. The proposed approach was tested in the case study of the historical center of Milan, leading to the proposal of integrations regarding the identification and mapping of the existing UGI and the planning of its future extension.