Introduction

Climate change is no longer a distant threat. People around the world are experiencing more frequent, intense or prolonged extreme weather, putting human lives and real properties, as well as biodiversity, at risk. _{Masson-Delmotte, V., Zhai, P., Pörtner, H.-O., Roberts, D., Skea, J., Shukla, P. R., Pirani, A., … Waterfield, T. (Eds.). (in press). Global Warming of 1.5°C: An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty, pp. 32. Retrieved from https://www.ipcc.ch/site/assets/uploads/sites/2/2019/05/SR15_SPM_version_ report_LR.pdf} Cities today not only have to grapple with the existing vulnerabilities of urban geographies, such as urban poverty, precarious livelihoods, and informal settlements located in hazardous areas, but are increasingly exposed to global environmental changes that exacerbate these vulnerabilities _{Parnell, S., Simon, D., & Vogel, C. (2007). Global environmental change: Conceptualising the growing challenge for cities in poor countries. Area, 39(3), 357-369. https://www.jstor.org/stable/40346051} such as urban heat island effect _{Grimmond, S. (2007) Urbanization and global environmental change: Local effects of urban warming. The Geographical Journal, 173(1), 83-88. https://doi.org/10.1111/j.1475- 4959.2007.232_3.x} and coastal flooding caused by sea level rise and extreme weather events. Amongst all of the environmental, social, and economic challenges, flood risk may be one of the most ubiquitous and challenging for policy makers and planners in the 21st century. _{Jha, A. K., Bloch, R., & Lamond, J. (2012). Cities and flooding: A guide to integrated urban flood risk management for the 21st century. Washington, D.C.: World Bank Publications} Flood risk in cities is caused by a variety of factors, chief among them being land use changes which have affected the natural hydrological cycle. _Ibid.  

River restoration is seen as an increasingly important strategy for reducing flood hazard, increasing access to open space, and restoring hydrological functionality simultaneously. _Ibid. However, many urban river restoration initiatives are limited in their potential by a lack of space for restoration due to high density urban development in the surrounding areas. We argue that relocation of vulnerable assets from floodplains is one way to enable more transformative river restoration projects while permanently eliminating risk to flood-vulnerable assets and people. However, removal of structures and relocation of people is not straight forward, especially due to a lack of suitable relocation sites in areas that lack open space for redevelopment. 

This article highlights the opportunity to restore degraded urban floodplains while increasing urban resilience using a swap strategy that replaces a proposal for open space in a low-vulnerability area with open space in a high-vulnerability area as part of the redevelopment of a decommissioned airport site. Using the Ayamama River and the Ataturk Airport site in Istanbul, Turkey as a case study, this approach provides a conceptual model for urban designers interested in maximizing floodplain restoration projects in urban centers, reducing risk to built assets and infrastructure, and more effectively ensuring the rights of relocated individuals and businesses.