Are rainfall extremes increasing in southern Italy?

Abstract

The growing number of extreme hydrological events observed worldwide has raised the level of attention towards the impact of climate change on the rainfall process, which is difficult to quantify given its strong spatial and temporal heterogeneity. Therefore, the impact of the climate change should be determined ranging from individual hydrological series to a regional and/or district scale. With this context, the present study aims to identify trends and dynamics in extreme sub-daily rainfall patterns in southern Italy from 1970 to 2020. A comprehensive database of annual maxima was constructed using all available rainfall data and further expanded through the implementation of the gap-filling procedure, specifically the spatially-constrained ordinary kriging method. This expanded dataset was utilized to explore regional and local trends in annual maxima, offering valuable insights into the evolving nature of rainfall patterns in recent years. While most of the observed trends did not reach statistical significance, a significant number of locations exhibited upward tendencies for shorter durations. It is noteworthy that these trends tended to disappear over longer durations.