Trends in heat and cold wave risks for the Italian Trentino-Alto Adige region from 1980 to 2018
In: Natural hazards and earth system sciences: NHESS, Band 23, Heft 7, S. 2593-2606
ISSN: 1684-9981
Abstract. Heat waves (HWs) and cold waves (CWs) can have considerable impact on
people. Mapping risks of extreme temperature at local scale, accounting for
the interactions between hazard, exposure, and vulnerability, remains a
challenging task. In this study, we quantify risks from HWs and CWs for the
Trentino-Alto Adige region of Italy from 1980 to 2018 at high spatial
resolution. We use the Heat Wave Magnitude Index daily (HWMId) and the Cold
Wave Magnitude Index daily (CWMId) as the hazard indicators. To obtain HWs
and CW risk maps we combined the following: (i) occurrence probability maps of the hazard
obtained using the zero-inflated Tweedie distribution (accounting directly
for the absence of events for certain years), (ii) normalized population
density maps, and (iii) normalized vulnerability maps based on eight
socioeconomic indicators. The methodology allowed us to disentangle the
contributions of each component of the risk relative to total change in
risk. We find a statistically significant increase in HW hazard and
exposure, while CW hazard remained stagnant in the analyzed area over the
study period. A decrease in vulnerability to extreme temperature spells is
observed through the region except in the larger cities where vulnerability
increased. HW risk increased in 40 % of the region, with the increase
being greatest in highly populated areas. Stagnant CW hazard and declining
vulnerability result in reduced CW risk levels overall, except for the four
main cities where increased vulnerability and exposure increased risk
levels. These findings can help to steer investments in local risk
mitigation, and this method can potentially be applied to other regions
where there are sufficient detailed data.