| ID | Explanation |
|---|---|
| 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. |
| S2 | Concentrations represent the urban background. This means that it does not reflect local extremes found close to roads or large emission sources. |
| S3 | Applied relative risks originate from studies of both finer and coarser spatial resolution compared to exposure data used here. |
| S4 | Future 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. |
| S5 | This is representative of selected points along the rivers. |
| S6 | Average outdoor, street-level conditions for each grid cell (resolution: 1 km), so does not resolve fine-scale variations resulting from different land uses. |