Increasing Heatwave Hazards in the Southeastern European Union Capitals

Abstract

Heatwaves (HWs) are one of the "natural" hazards with the greatest impact worldwide in terms of mortality and economic losses, and their effects may be exacerbated in large urban areas. For these reasons, more detailed analyses of urban HW trends represent a priority that cannot be neglected. In this study, HW trends were investigated during the warmest period of the year (May-September) by using a slightly improved version of the EuroHEAT HW definition applied on long meteorological time-series (36-year period, 1980-2015) collected by weather stations located in the capitals of the 28 European Union member countries. Comparisons between two 18-year sub-periods (1980-1997 vs. 1998-2015) were carried out and a city-specific HW hazard index (HWHI), accounting for the main HW characteristics, was proposed. Most of the capitals revealed significant positive trends of the majority of HW hazard characteristics and substantial HWHI increases were observed during the sub-period 1998-2015, especially in the central-eastern and southeastern cities. Conversely, minor HWHI increases were observed in most of the northern capitals and opposite situations were even observed in several northern and especially southwestern cities. The results of this study represent a support for planning urban HW-related mitigation and adaptation strategies with the priority given to the southeastern cities.

Urban Imperviousness Effects on Summer Surface Temperatures Nearby Residential Buildings in Different Urban Zones of Parma

“…This is in agreement with the fact that the UHI is a typically nighttime phenomenon [53,57] when the radiation stored during the day in the densely built-up areas is released into the atmosphere during the night [29]. These findings are especially useful in a country such as Italy where frequent and often intense heat waves occur during summer, and a general increased earliness in the occurrence of the most critical heat waves was observed at the end of June [58], when day-length is a risk factor with often devastating effects for the general population and especially the most vulnerable subjects [59,60].…”

“…This is a priority because of the rapid and unplanned urban growth as well as the ongoing trends in global warming. In particular, the consequent increase in the frequency and intensity of heat-waves in urban environment [58] necessitate thorough and detailed investigations on the effect of urbanization on the urban thermal environment to provide effective summer UHI mitigation strategies.…”

Historical Trends and Variability in Heat Waves in the United Kingdom

“…The median numbers and lengths (Table 1) for stations in or close to London and in Northern Ireland were similar to those calculated for London and Dublin using a different heat wave definition [9]. Positive trends in numbers and lengths of longest heat waves were identified at many stations using data from 1961.…”

“…The number of heat waves over this period had not changed, but heat waves after about 1990 had higher maximum temperatures and longer durations. Significant positive trends in numbers of heat wave days and heat wave lengths were identified in many south eastern European cities [9], although the period of data used was fairly short . In a study of heat waves in Ukraine using temperatures recorded over 1951-2011, the largest numbers of heat waves were found in the most recent decade (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010), and the fewest in 1961-1970 and 1971-1980 [10].…”

Comprehension of climatic and occupational heat stress amongst agricultural advisers and workers in Slovenia

“…Climate changes are expected to alter the future thermal conditions and for Slovenia it is forecasted that with a moderate greenhouse gas emission scenario (RCP4.5) an increase of annual average air temperature by 1°C in the period 2011-2040 regarding 1981-2010 and by another 1°C in the period 2041-2070 is expected (ARSO, 2016;Morabito et al, 2017). Direct productivity losses associated with occupational heat stress may become substantial Nybo et al, 2017) and if risk factors and costs related to deal with at higher levels of warming are considered, it will have immense impact for workers and employers relying on outdoor or non-air conditioned work.…”