Analysis of Dry Spells in Southern Italy (Calabria)

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.

Drought Analysis in Europe and in the Mediterranean Basin Using the Standardized Precipitation Index

“…Stagge et al [8] and Lloyd-Hughes and Saunders [9] analyzed some of the major large-scale droughts in Central and Eastern Europe. Drought studies at a national scale have also been performed in Central Europe [10,11] and in some Mediterranean countries [12][13][14].…”

SPI Trend Analysis of New Zealand Applying the ITA Technique

“…In recent years, several researchers have analyzed drought events in several parts of the world [10][11][12][13][14][15][16][17], even though drought phenomena are difficult to detect and to monitor due to their complex nature. Usually, drought severity is evaluated by means of drought indices since they facilitate communication of climate anomalies to diverse user audiences; they also allow scientists to assess quantitatively climate anomalies in terms of their intensity, duration, frequency, recurrence probability, and spatial extent [3,18].…”

Regional Frequency Analysis of Extreme Dry Spells during Rainy Season in the Wei River Basin, China

“…Therefore, studying the changing patterns of precipitation is of great importance for the evaluation of hydrological and meteorological consequences, for example, drought and flooding events, associated with global warming. In particular, as one of the costliest natural disasters through the agrosocioeconomic aspects in many areas of the world [4][5][6], droughts are expected to occur more frequently, caused by the predicted changes in the hydrologic cycle [7,8]. Meanwhile, they are also supposed to largely affect the socioeconomic activities, water resources management, agriculture policies, and so forth [3].…”

“…Many studies have been performed for the research of drought, such as the definition and evaluation of droughts, including the spatiotemporal structure and statistical characteristic analysis, [3,4,9,10] and the multivariable probability distributions jointly considering multiple drought variables (such as duration, severity, and magnitude) simultaneously [11][12][13]. Knowledge about the anticipated changes in drought frequency or magnitude by means of persistent daily precipitation deficiency (i.e., dry spell of precipitation) has attracted more and more interest [8,[14][15][16][17] and is considered to be necessary for the design and application of valid and reasonable drought resistance strategies. Here, dry spell, which may provide relevant information about drought regimes, can be defined as the uninterrupted period with daily precipitation amount less than a certain threshold, followed and preceded by at least one day with precipitation amount larger than the threshold [8,15,18].…”