Micro-scale urban surface temperatures are related to land-cover features and residential heat related health impacts in Phoenix, AZ USA

Abstract

Context With rapidly expanding urban regions, the effects of land cover changes on urban surface temperatures and the consequences of these changes for human health are becoming progressively larger problems. Objectives We investigated residential parcel and neighborhood scale variations in urban land surface temperature, land cover, and residents' perceptions of landscapes and heat illnesses in the subtropical desert city of Phoenix, AZ USA. MethodsWe conducted an airborne imaging campaign that acquired high resolution urban land surface temperature data (7 m/pixel) during the day and night. We performed a geographic overlay of these data with high resolution land cover maps, parcel boundaries, neighborhood boundaries, and a household survey. Results Land cover composition, including percentages of vegetated, building, and road areas, and values for NDVI, and albedo, was correlated with residential parcel surface temperatures and the effects differed between day and night. Vegetation was more effective at cooling hotter neighborhoods. We found -015-0284-3 consistencies between heat risk factors in neighborhood environments and residents' perceptions of these factors. Symptoms of heat-related illness were correlated with parcel scale surface temperature patterns during the daytime but no corresponding relationship was observed with nighttime surface temperatures. Conclusions Residents' experiences of heat vulnerability were related to the daytime land surface thermal environment, which is influenced by micro-scale variation in land cover composition. These results provide a first look at parcel-scale causes and consequences of urban surface temperature variation and provide a critically needed perspective on heat vulnerability assessment studies conducted at much coarser scales.Landscape Ecol (2016) 31:745-760 DOI 10.1007/s10980

Hot playgrounds and children's health: A multiscale analysis of surface temperatures in Arizona, USA

“…Vegetation is also found more effective at cooling hotter neighborhoods (Jenerette et al, 2015). However, this cooling effect as studied costs a substantial amount of water to achieve-an expensive proposition in a desert city.…”

“…This TIR data captures near-peak surface temperatures (T s ) with a higher spatial and spectral resolution compared to many sensor systems (e.g., Stefanov et al, 2004;Van Der Meer & de Jong, 2001). The MASTER data used in this study were acquired midday (1100-1330 h LST) on July 13, 2011 (Jenerette et al, 2015). The geo-referenced LST data are further extracted by each parcel polygon (obtained from cadastral GIS vector layer) to represent the parcel mean LST (see Fig.…”

“…2). Further details regarding the MASTER overflight and processing of the data to obtain LST can be found in Jenerette et al (2015). The retrieved resolution (6.8 m) of the T s data from the MASTER sensor allow for microclimate-related analysis and also allow for comparison with touch-scale in situ site playground measurements detailed below.…”

“…Our findings and data also speak directly to such building energy considerations. In a very hot climate like Phoenix, carefully designed shade has the helpful characteristic of lowering thermal loads and T s during the daytime year-round, where daytime reductions in T s may be more effective in reducing health risks than nighttime (Jenerette et al, 2015). In a colder climate, it might be important to avoid shading the microenvironment during the day during winter.…”

On the effects of landscape configuration on summer diurnal temperatures in urban residential areas: application in Phoenix, AZ

“…In contrast, cool or green roofs (Georgescu et al 2014;Gill et al 2007;Jacobson & TenHoeve 2012;) and the vegetation or green space fraction (e.g., Akbari et al 2001;Akbari & Mathews 2012;Bowler et al 2010;Li et al 2011;Li et al 2012;Wong & Yu 2005;Zhou et al 2011) attenuate temperature extremes. In addition to these land-cover composition characteristics, evidence mounts that the configuration of the land system-the pattern and shape of individual land covers or their mosaics-affects urban temperatures as well (Huang & Cadenasso 2016;Li et al 2012;Li et al 2016;Li et al 2017;Maimaitiyimi et al 2014;Xiao et al 2007;Zhou et al 2011). The heat vulnerability of neighborhoods is a significant concern for the metropolitan area of Phoenix, Arizona (USA), where maximum summer daytime temperatures routinely exceed 40 o C in summer and have reached 50°C (122°F) (Middel et al 2012).…”