Spatial representation

S1 This indicator is an average outdoor, street-level conditions for each grid cell at a
resolution of 1 km. This means fine-scale variations resulting from urban geometry
(building or tree heights, for example) are not resolved. Thus, there may be higher
uncertainty in spatially complex settings such as city centres with a high degree of
fine-scale spatial variation in surface geometry (e.g. from building
shadows/reflections, anthropogenic heat sources).
For example, 2 m outdoor urban air temperatures are affected by micro-scale
urban geometry through sky-view factor and longwave radiation energy loss,
thermal surface properties (via overnight storage heat releases), and
anthropogenic heat emissions.
S2Concentrations represent the urban background. This means that it does not reflect
local extremes found close to roads or large emission sources.
S3Applied relative risks originate from studies of both finer and coarser spatial
resolution compared to exposure data used here.
S4Future modelled changes in these indicators are predominantly due to atmospheric
and climate processes operating on larger scales (regional, global) than urban
areas. Thus, spatial variation within an urban area at 1 km x 1 km grid resolution is
expected to be minimal.
S5This is representative of selected points along the rivers.
S6Average outdoor, street-level conditions for each grid cell (resolution: 1 km), so
does not resolve fine-scale variations resulting from different land uses.