High-Resolution Lightning Detection and Possible Relationship with Rainfall Events over the Central Mediterranean Area

Abstract

Lightning activity is usually associated with precipitations events and represents a possible indicator of climate change, even contributing to its increase with the production of NOx gases. The study of lightning activity on long temporal periods is crucial for fields related to atmospheric phenomena from intense rain-related hazard processes to long-term climate changes. This study focuses on 19 years of lightning-activity data, recorded from Italian Lightning Detection Network SIRF, part of the European network EUCLID (European Cooperation for Lightning Detection). Preliminary analysis was dedicated to the spatial and temporal assessment of lightning through detection in the Central Mediterranean area, focusing on yearly and monthly data. Temporal and spatial features have been analyzed, measuring clustering through the application of global Moran’s I statistics and spatial local autocorrelation; a Mann–Kendall trend test was performed on monthly series aggregating the original data on a 5 × 5 km cell. A local statistically significant trend emerged from the analysis, suggesting possible linkage between surface warming and lightning activity.

Terraced Landscapes on Portofino Promontory (Italy): Identification, Geo-Hydrological Hazard and Management

“…Terraces and associated soil and debris may represent source areas for shallow landslides [64] and fast developing processes like debris flow and hyper-concentrated flow that can be triggered by intense rain events [47,51]: several events happened in the Liguria region in the recent past. These processes may affect buildings, infrastructures and Cultural Heritage causing a high potential damaging effect on people and on the local economy.…”

“…Geology is characterized by the Conglomerate, that includes the south facing portion of the promontory, and by the marly limestone flysch (Mt. Antola Flysch) near the link with the coastline [44,51]. The contact between the two formations, partially due to tectonic activity, is oriented WNW-ESE from Cervara to San Nicolò.…”

“…The circulation generates intense rain precipitations, mainly between August and November, with events with high, short duration peaks that usually exceed 50 mm/h in less than 6 hours. The related ground effects are often severe with floods and spread shallow landslides that cause damage and, occasionally, even casualties [48][49][50][51]. The more frequent and widespread geo-hydrological hazards are debris/mud flows and flash floods, always involving exposed elements such buildings and infrastructures.…”

“…Severe rain events are an increasing occurrence in the last 50 years in Liguria Region [47][48][49][50][51]. Consequently, these events cause an intensification of geo-hydrological hazard that, in the Portofino promontory, resulting in significant damage to buildings, infrastructures and, sometimes, casualties.…”

Geomorphological Landscape Research and Flood Management in a Heavily Modified Tyrrhenian Catchment

“…Many case studies in Mediterranean countries highlight an increase in the frequency and violence of floods [19,20] and link flash floods and stream power to both climate change and urban sprawl [21][22][23]. In the Italian peninsula, flood hazard is particularly common due to geomorphologic and climatic features and its primary effects include damage to buildings, infrastructure and loss of life [24].…”