Effects of urban growth spatial pattern (UGSP) on the land surface temperature (LST): A study in the Po Valley (Italy)

Sealed surfaces greatly influence Urban Heat Island (UHI) effects. In this respect, both the composition and spatial patterns of anthropogenic land use play an important role in local thermal pattern. The urban environments' climate change adaptation strategy needs adequate knowledge systems urban planners can use to organise and design more resistant and resilient urban spaces. This study examined the relationship between Land Surface Temperature (LST) variations and increasing urbanised areas during the period 2001-2011 in the Po Valley, utilising different urban growth spatial patterns (UGSP). Remotely sensed LST data was obtained from MODIS (MODerate Resolution Imaging Spectroradiometer) at a resolution of 1 km/pixel for an 11 year-period, from 2001 to 2011, with urbanisation data from the ISTAT map (nominal scale 1:10,000) respectively for the 2001 and 2011 time sections. The relationship between dependent (mean annual daytime, nighttime and daily values) and independent (urbanised areas) variables were investigated through ANOVA test and post-hoc analysis (p < 0.01) for all defined UGSP. Results showed that there is a decreasing LST range (in all conditions) associated with progressive increase of urbanised areas. Furthermore, clustered patterns urban growth have a statistically significant relationship with daytime, nighttime and daily conditions while dispersed pattern urban growth have the same with nighttime only. The outcomes are helpful for understanding the effects of different UGSP, which have significant implications for urban planning, and identifying the critical territorial sectors in need of sustainable mitigation actions.