Abstract
Precipitation variability in space and time has been a focus of research over the past decades. The largest body of literature was essentially focused on long-term changes in average climates and in climate extremes. Analyses of the changes in the inter-annual climate variability (the year-to-year variability), which represent an index of climatic risk, received instead very less attention, but it represents an important issue in order to quantitatively measure the socioeconomic impact of climate change impact over water resources. In order to depict a general characterization of the long-term climate variability for the Campania region, located in Southern Italy within the Mediterranean basin, an analysis of the precipitation coefficient of variation, assumed as an index of inter-annual climate variability, was performed over the period 1918–2015 and compared with the annual precipitation regime and the intra-annual precipitation variability of the same region. The Mann–Kendall and the modified Mann–Kendall tests were applied to detect the sign and significance of the temporal changes and Sen’s test was applied to quantify the temporal changes in inter-annual variability. The results illustrated a generalized condition (73% of total stations) of statistically significant increase of inter-annual variability distributed almost over the whole analyzed area, even though the detected change appeared rather moderate in magnitude. The relationship between annual precipitation, intra-annual precipitation variability, and inter-annual precipitation variability was not clearly identified for the studied region, likely because of the characteristics of climatic homogeneity for the area under investigation. However, the comparative analyzes clearly showed how, if the variations in the annual precipitation regime and in the intra-annual precipitation variability are poorly significant (respectively for 9% and 11% of total station), changes in inter-annual precipitation variability are strongly marked over the studied region.
Highlights
Water scarcity is a recurring and worldwide phenomenon, with spatial and temporal characteristics that vary significantly from one region to another (Tallaksen and Van Lanen 2004)
The climate change is likely to accelerate the climate-meteo-hydrological processes able to lead toward intense drought episodes (Longobardi and Van Loon 2018) and understanding historical precipitation variability is necessary to plan mitigation strategies to face future climate change impacts
Available data consist of annual and monthly precipitation time series for over 300 sites located across the Campania region and the Lazio region
Summary
Water scarcity is a recurring and worldwide phenomenon, with spatial and temporal characteristics that vary significantly from one region to another (Tallaksen and Van Lanen 2004). The climate change is likely to accelerate the climate-meteo-hydrological processes able to lead toward intense drought episodes (Longobardi and Van Loon 2018) and understanding historical precipitation variability is necessary to plan mitigation strategies to face future climate change impacts. Temporal and spatial changes in climate extremes were intensively studied (Hamilton and Keim 2009; Sohoulande djebou and Singh 2016; He and Li 2019). Changes in average and extreme climates have an undoubted effect on water resources assessment, floods, and drought management, and affect plant growth, agricultural production, and the biogeochemical cycle. The interannual precipitation variability is intended as the year-to-year variability in cumulative precipitation occurrences and can represent an index of climatic risk, as long as it marks the possibility for a random sequence of years of rainfall abundance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
