The elevated temperatures we experience in cities are largely due to abundance of dark, impervious surfaces and the lack of vegetation. Implementing green and reflective infrastructure (smart surfaces) is an effective strategy for lowering temperatures but requires actionable data to both map where implementation can occur and provide a baseline against which to measure change.

By combining globally available and open data from Open Street Maps and satellite imagery, WRI is mapping urban surfaces that influence heat dynamics like roads, buildings, parking lots and public open space. We are combining this data with satellite remote sensing and AI-generated datasets to map the reflectivity, tree cover and vegetative cover of urban surfaces, allowing us to characterize baseline conditions and identify opportunities for implementing green and reflective infrastructure.

We take the following approaches to advancing understanding of surface conditions and potential for heat mitigation:

  • Using open-source data and methods applicable across all US cities, we map urban land use and land cover (LULC) in a way that cities can use. Because not all cities have access to high-resolutions maps of their built environment, we use only freely available data to improve access and equity. To account for the fact that most existing LULC data does not contain the kinds of features—like roads, buildings, and parking lots—where smart surfaces can be implemented, we create methods to specifically capture these categories.
  • To help cities understand the potential of specific surfaces to mitigate heat, we provide estimates of the quality of a range of surfaces, focusing on reflectivity and greenery. We measure the reflectivity of surfaces like roofs, roads and parking lots and assess the percentage of tree and vegetation cover so cities can have a baseline from which to assess their progress on heat mitigation.
  • While the dynamics of urban heat are complicated, we provide clear, accessible, and data-backed information to help cities make progress. Equipping cities with meaningful interpretations of the data can help them develop effective and context-specific heat-related policies.