Spatiotemporal variability of compound droughts and hot extremes in East Australia

Droughts and hot extremes generate agricultural losses, forest death, and drinking water scarcity, especially when they happen simultaneously. In addition, drought appears to be linked to climate change in the same way that heat waves are. The rise in frequency and intensity of drought poses a severe danger, such as an increase in the number, size, and duration of bushfires. Even today, our understanding of how droughts and heat waves begin and evolve, as well as how climate change may affect these extreme events (droughts and heat waves), is limited. So far, numerous studies have been undertaken on the variability of individual droughts or hot extremes in Australia. However, the analysis of combined droughts and hot extremes, which might have even more significant effects than a single drought or hot extreme, is still inadequate. In this study, changes in the spatial extent of combined droughts and hot extremes in Eastern Australia have been investigated, considering daily precipitation and temperature data for 50 years between 1971 to 2021. For detecting and characterising the drought Standardised Precipitation Index (SPI) method has been used, and the hot extremes were evaluated based on the criterion given by the Australian Bureau of Meteorology (daily maximum temperature > 35 â°C). A linear regression method has been adopted to explore the trends of these climatic variables. All the stations have shown a general increase in combined drought and hot days. These findings demonstrate the variability of compound droughts and hot extremes and may provide helpful understanding to lessen the impact of extreme events in East Australia's region in the future.