Analysis of Dry Spells in Southern Italy (Calabria)

Tommaso Caloiero,Roberto Coscarelli,Ennio Ferrari,Beniamino Sirangelo

doi:10.3390/w7063009

Tommaso Caloiero, Roberto Coscarelli + Show 2 more

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https://doi.org/10.3390/w7063009

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Abstract

A deficit in precipitation may impact greatly on soil moisture, snowpack, stream flow, groundwater, and reservoir storage. Among the several approaches available to analyze this phenomenon, one of the most applied is the analysis of dry spells. In this paper, an investigation of the spatial and temporal patterns of dry spells, in a region of southern Italy, has been carried out on a daily precipitation dataset. First, the frequency distributions of the sequences of dry days have been analyzed. Then, the regional areas most affected by dry events have been evaluated at annual and seasonal scale. Finally, the long-term trend of the dry spells has been estimated at annual and seasonal scale. Results show that the lower probabilities of long dry spells occur in the main reliefs of the region, while the highest values have been detected in the Ionian side. The spatial distribution of the mean and maximum length values of the dry spells evidenced a west–east gradient. The trend analysis mainly revealed a negative behavior in the duration of the dry spells at annual scale and a positive trend in the winter period.

Highlights

Following the increase in anthropogenic greenhouse gas concentrations, numerous studies on climate change have detected an important tendency towards a global warming in the last decades [1], with changes in precipitation regimes [2,3] as well as in storm tracks [4,5]
The spatial and temporal patterns of dry spells in Calabria have been analyzed using a daily precipitation dataset, formed by 129 rainfall series collected in the period 1941–2006
A correspondence between the orography and the distribution of the dry spells has been detected: the highest values have been observed on the coastal areas, whereas the lowest ones have been found on the mountains

Summary

Introduction

Following the increase in anthropogenic greenhouse gas concentrations, numerous studies on climate change have detected an important tendency towards a global warming in the last decades [1], with changes in precipitation regimes [2,3] as well as in storm tracks [4,5]. Several studies conducted at global [6,7], regional [8,9], and sub-regional scales [10,11,12] have evidenced growing precipitation change at different timescales. In southern Italy [21], and in the Calabria region [22,23,24,25,26,27], different studies highlighted a decreasing trend in winter and autumn rainfall, and an increasing trend in spring and summer

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