Do recent meteorological drought events in central Italy result from long‐term trend or increasing variability?

Abstract

The Mediterranean area is one of the most important “hotspot” where the effects of climate change are more evident, with an increase of extreme events such as hot waves and intense droughts. From this perspective, central Italy, which in the recent past suffered from the impact of intense negative anomalies of precipitation on water resources, shows peculiar characteristics, being its meteoclimatic regime determined by global, regional and local factors. In this context, this study aims at exploring the variability in time and space of the precipitation regime in central Italy over the period 1960–2020 analysing global factors, represented by indexes of teleconnection, and local factors such as orography and distance to the sea. Findings indicate an increase of drought events during the last 20 years, in a general pattern characterized by stationary precipitation amounts. This trend is clearer on the Tyrrhenian coast with a number of months under severe drought conditions increasing from 5% (1965–1999) to 24% (2000–2020). The strengthening of the periodic signal of precipitation is related mainly to the Atlantic Multidecadal Oscillation Index and the Western Mediterranean Oscillation Index. Considering the relationship between precipitation and teleconnection patterns over short time scales (few months), correlations are stronger with the North Atlantic Oscillation index and in general with the Atlantic patterns rather than with the Artic patterns, especially for the Adriatic side.

Total Mercury Mass Load from the Paglia–Tiber River System: The Contribution to Mediterranean Sea Hg Budget

“…Unfortunately, here, we cannot compare the suspended particulate transported in different seasons and catchments because TSS values were only measured in November 2020. In the last few decades, changing climatic conditions triggered the Mediterranean area with shifts in climatic variability, with increasing heat waves, intense drought, and heavy rains [ 64 , 65 , 66 ]. In Central Italy (Tyrrhenian coast), an increase in drought events was recorded during the last 20 years, with the number of months under severe drought conditions increasing from 5% (1965–1999) to 24% (2000–2020) [ 65 ].…”

“…In the last few decades, changing climatic conditions triggered the Mediterranean area with shifts in climatic variability, with increasing heat waves, intense drought, and heavy rains [ 64 , 65 , 66 ]. In Central Italy (Tyrrhenian coast), an increase in drought events was recorded during the last 20 years, with the number of months under severe drought conditions increasing from 5% (1965–1999) to 24% (2000–2020) [ 65 ]. For example, in the Tiber River hydrographic district, the impact of an intense drought period from winter to early autumn 2017 also caused a decrease in water resources availability in the city of Rome [ 65 ].…”

“…In Central Italy (Tyrrhenian coast), an increase in drought events was recorded during the last 20 years, with the number of months under severe drought conditions increasing from 5% (1965–1999) to 24% (2000–2020) [ 65 ]. For example, in the Tiber River hydrographic district, the impact of an intense drought period from winter to early autumn 2017 also caused a decrease in water resources availability in the city of Rome [ 65 ]. Thus, the Hg loads estimated during these two different campaigns provide a quantitative picture of the Hg transport in Tiber River and its main tributaries during a drought and wet period, highlighting conditions expected to become very frequent.…”

Long-range, time-varying statistical prediction of annual precipitation in a Mediterranean remote site

“…Here we address the issue of the reliability of long-term forecasting using the ARIMA model and the Exponential Generalised Autoregressive Conditional Heteroscedasticity (EGARCH) technique for understanding climate trend variability and for water resource management in the Mediterranean region, which has been identified as a hotspot for climate change and where sub-regional studies are recommended (Hartmann et al 2013, Romano et al 2022. In this context, the climate signals detected in the remote site of Montevergine (southern Italy) are particularly representative of the climate change associated with the rainy transient across the Mediterranean.…”

A Step-Wise Modelling Approach to Identifying Structural Features That Control Groundwater Flow in a Folded Carbonate Aquifer System

“…These resources are very often exploited to supply large urban areas, and the evaluation of the possible negative effects of climate changes on their discharge is challenging. The decrease in annual precipitation and increase in temperature and evapotranspiration due to climate change in the Mediterranean area ( [5]- [9]), is leading to a general decline both in surface water discharge ( [10]) and in recharge to groundwater ([11]). Preziosi and Romano, 2013 [12] highlighted that spring discharge of large carbonate aquifers in central Italy has decreased by 6% to 42% in the period 1938-2011, the highest percentages estimated for the smallest springs ( [13]).…”