Developing open space networks in shrinking cities

Urban green spaces provide essential ecosystem services and improve resident quality of life, but open space networks are often fragmented by urban development, and it is difficult to reclaim natural lands after they have been built up. Shrinking cities (i.e., cities experiencing population decline) typically contain an abundance of vacant and abandoned residential buildings that are demolished for safety and maintenance reasons. The resulting empty lots can potentially be reclaimed as natural areas to defragment the green network and increase open space connectivity. To date however, planning efforts have largely ignored post-demolition land uses for these lots, allowing many to become empty wastelands. This research approaches this gap by presenting an alternative plan for residential demolition sites using landscape ecology principles and methods to incorporate them into the open space network. Using Buffalo, NY - a typical rustbelt shrinking city - as a case study, areas most at risk for experiencing demolitions are identified using a clustering technique, and each building within the cluster is assigned a likelihood it will be demolished using a logit model. Properties with the highest risk for demolition are then prioritized based on their ability to contribute to and connect the open space network using landscape connectivity metrics. Results indicate the approach can foster large increases in green network connectivity using small parcels (a 356% increase in total open space area was observed in this study after three years of purposeful selection), allowing cities to reclaim unused urban areas and defragment the open space network.