Equitable public green infrastructure for cooling off from extreme heat in Bochum, Germany: A public participation geographic information system (PPGIS) survey

Abstract

Extreme heat in urban areas is projected to increase due to climate change. While the elderly and infirm are particularly vulnerable, other factors such as social status and education level can also increase the risk of negative impacts due to heat. Consideration of such individual and social characteristics is relevant for promoting environmental justice - defined as the “avoidance and reduction of the spatial concentration of environmental burdens relevant to health and as a guarantee of socio-spatially equitable access to environmental resources (BMUB 2016, 7)”. Equitable and environmentally just adaptation to climate change should be an increasingly urgent priority for cities in the coming years to ensure the safety of those who may be most negatively affected.

One adaptation measure is to develop urban green infrastructure (UGI), a type of nature-based solution (NbS) that includes green and blue spaces and can reduce temperatures in cities (e.g., through mitigation of the urban heat island effect) as well as provide cooling oases for local citizens on hot days. UGI and associated benefits can thus be considered ‘environmental resources’ that may have varying degrees of availability, access, and quality within different neighborhoods and for different people. In addition, individual preferences and values can influence why people visit or avoid certain UGI, and characteristics such as shade, air movement (breeze), and the presence of water can both reduce temperatures and attract users. Thus, to effectively plan environmentally just UGI, it is necessary to understand how they are being (under)used, by whom, and why.

We use the public participation geographic information system (PPGIS) platform (MaptionnaireTM) to conduct a survey (closed 28.02.23) exploring UGI use in relation to extreme heat among residents of Bochum, Germany. We are guided by three research questions: i) To what degree do different residents rely on UGI to reduce exposure to extreme heat?; ii) What places within the UGI are preferred for visiting to cool off during extreme heat?; and iii) What characteristics of UGI are visitors most satisfied with for cooling off during extreme heat? We conduct spatial and statistical analyses and assess environmental justice by comparing satisfaction of UGI characteristics with an index of social vulnerability, perceived heat risk, and residential location of respondents. The potential of PPGIS for informing urban climate adaptation to extreme heat is a current research gap. Our findings can inform the environmentally just adaptation planning of UGI in Bochum and provide a methodological template for researchers and other global cities facing extreme heat.

BMUB. 2016. “Umweltgerechtigkeit in Der Sozialen Stadt: Gute Praxis an Der Schnittstelle Von Umwelt, Gesundheit Und Sozialer Lage.” https://www.bundesregierung.de/breg-de/suche/umweltgerechte-stadt-2156340.