Heat Resilience - Outdoor exposure LSOA

Mean land surface temperature Satellite based land surface temperature. The readings are based on the average of different summertime images. In degrees Celsius, these readings are then averaged across the LSOA, to give one reading per LSOA. Land surface temperature is often used as a proxy for air temperature to help understand variation in temperature across a city. Normalised Difference Vegetation Index Normalised Difference Vegetation Index or NDVI and can be used to estimate the density of greenness of an area of land. The index ranges from +1 to -1 with higher values representing more greenspace. The readings are based on the average different satellite images. % of homes near busy roads % of homes per LSOA which sit within 50m of a B-road or larger. Population density Population density per LSOA (population per Km2). Higher population density can be used as a proxy for increased anthropogenic heat emissions (from human activities) which might influence the Urban Heat Island effect. This factor is based on data from the 2019 mid-year population estimates. [Office for National Statistics Lower Super Output Area population estimates (supporting information) (ons.gov.uk).] Air pollution (NOx) Mean NOx reading per LSOA, based on modelled background air pollution data provided by DEFRA. [Department for Environment Food & Rural Affairs - UK Air Information Resource - Modelled background pollution data (uk-air.defra.gov.uk)]. NOx refers to a combination of nitrogen dioxide (NO2) and nitric oxide (NO) which are produced by combustion processes. Higher pollution levels may make it less likely that people will open windows (when done at the right time this can help with cooling homes). Air pollution (PM 10) Mean PM10 reading per LSOA, based on modelled background air pollution data provided by DEFRA. [Department for Environment Food & Rural Affairs - UK Air Information Resource - Modelled background pollution data (uk-air.defra.gov.uk)]. Higher pollution levels may make it less likely that people will open windows (when done at the right time this can help with cooling homes). Air pollution (PM 2.5) Mean PM2.5 reading per LSOA, based on modelled background air pollution data provided by DEFRA. [Department for Environment Food & Rural Affairs - UK Air Information Resource - Modelled background pollution data (uk-air.defra.gov.uk)]. Higher pollution levels may make it less likely that people will open windows (when done at the right time this can help with cooling homes). Building height Mean building height per LSOA. Ordnance Survey Building Height data containing spatially referenced outlines and heights of all buildings in Bristol was used. Here GIS was used to assign buildings per LSOA to calculate the mean building height in metres for each LSOA. Land covered by buildings The % of land within an LSOA covered by buildings. Ordnance Survey Building Height data containing spatially referenced outlines and heights of all buildings in Bristol was used. Here the area of land covered by buildings per LSOA was calculated using GIS. Mean distance to greenspace This layer gives a proxy for the mean distance to greenspace (in metres) for each LSOA. LSOA's were covered in points at 100m intervals and the distance to greenspace larger than 600m2 was calculated for each one. The mean for each LSOA of these distances was then found. Greenspace was derived from UK's Centre for Ecology and Hydrology 2020 Landcover maps. [UK Centre for Ecology & Hydrology Land Cover Maps (ceh.ac.uk]). Normalised Difference Built-up Index Normalised Difference Built-up Index or NDBI can be used to estimate the density of built-up areas. The index is based on a 2020 summer Landsat 8 image. [US Geological Survey EarthExplorer (ugs.gov).] Greenspace The % of land per LSOA classified as greenspace using the UK's Centre for Ecology and Hydrology 2020 Landcover maps. The land classifications of Broadleaved Woodland, Coniferous Woodland, Arable and Horticulture, Improved Grassland, Improved Grassland, and Fen Marsh and Swamp were all included in greenspace. [UK Centre for Ecology & Hydrology Land Cover Maps (ceh.ac.uk)]. Blue space The % of land per LSOA classified as blue space using the UK's Centre for Ecology and Hydrology 2020 Landcover maps. The land classifications of Saltwater and Freshwater were both included in blue space. [UK Centre for Ecology & Hydrology Land Cover Maps (ceh.ac.uk)]. Urban (%) The % of land per LSOA classified as 'Urban' according to the UK's Centre for Ecology and Hydrology 2020 Landcover maps. [UK Centre for Ecology & Hydrology Land Cover Maps (ceh.ac.uk)]. Suburban (%) The % of land per LSOA classified as suburban according to the UK's Centre for Ecology and Hydrology 2020 Landcover maps. [UK Centre for Ecology & Hydrology Land Cover Maps (ceh.ac.uk)].