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A research on records of mud volcano activity, as reported in historical literature, was carried out. The analysis deals with the Nirano Nature Reserve and, in general, with similar geological phenomena in the Modena and Reggio Emilia Apennines (Italy). The literature was divided into two parts: i) quasi-historical publications, from 1966 to 2004; ii) scientific-historical reports written by Authors from the 18th to the early 20th century. Activations documented in more ancient times (Roman Age, 16th, 17th centuries) were quoted as well. For the first time, information on positioning, years of recorded activations and type of episodes were collected and analyzed by means of GIS techniques. Maps of mud volcano distribution were drawn up and the documented number of activations was reported. Graphs showing the number of activations per year were produced. Mud volcano groups in Montegibbio and Regnano show the highest numbers of recorded activations, characterized by explosive episodes due to gas accumulation. In the Nirano area, mud and gases flow out of the vents with a more regular and continuous pattern, though mud extrusions are documented even in recent times, e.g. by a photo taken in 1937. GIS elaborations on the explosive activation described by the Roman scientist Pliny the Elder along the Roman "Via Æmilia" and referred to 91 BCE were carried out. Considering the distance of the observation point, these may be related to the Montegibbio mud volcanoes, if the Nirano field was already in a depressed area, as it is nowadays. [ABSTRACT FROM AUTHOR]

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In 2015 an intense rainfall event hit the Valleys of the Trebbia, Nure, and Aveto watercourses in the Northern Apennines. In about 6 h a mesoscale convective system deployed a stunning amount of precipitation of 340 mm, with an extreme hourly rainfall intensity of >100 mm/h. It triggered debris flows along slopes and stream channels, landslides and floods, which caused serious damages. Through the optimal combination of rainfall data and radar volumes, in this work we present a detailed rainfall analysis, which will serve as a basis to create a quantitative correlation with debris flows over elementary hydrological units. We aim at providing an objective basis for future predictions, starting from the recognition of the forcing meteorological events, and then arriving at the prediction of triggering phenomena and to the debris-flow type. We further provide seven observations/case studies on the effects of extreme-precipitation events on freshwater environments in small mountain catchments. Extreme-precipitation events are becoming more frequent and widespread globally but their ecological effects are still insufficiently understood. In general, the effects of extreme events on inland-waters' ecosystems are highly context-dependent, ranging from deleterious to beneficial. We therefore highlight the necessity of further studies to characterize these effects in more depth to be able to include appropriate mitigation measures in environmental planning and stewardship. [ABSTRACT FROM AUTHOR]

Contact: mariateresa.denardo@regione.emilia-romagna.itKeywords: drought, heavy rainfall events, Earth and Climate Sciences, Emilia-Romagna Apennines, Piacenza and Parma provincesThe provinces of Piacenza and Parma make up the western sector of the Emilia-Romagna region (Italy). In the last four years, this area has been interested by heavy rainfall events and a severe drought :1. October, 13th, 2014, Parma province. Heavy rainfall, lasting 6 hours and moving from mountain to plain areas, occurred; peak recorded intensity of 82 mm/h. Among the effects: crisis of small catchment basins in mountain areas; debris flow and erosive phenomena affecting streams and minor river courses. Main river courses were interested by floods, among them the Po River which receives the tributaries within Parma province. The city of Parma had some districts submerged itself.2. September 13th-14th, 2015, Piacenza province. Heavy rainfall, lasting 6-7 hours, affected highly elevated catchment basins in mountain areas. Among the effects: crisis of small, steep-slope catchment basins; widespread development of more than 300 debris flow accumulations, affecting river courses (1st to 3rd order, according to Strahler's classification); floods with debris loading in hilly and plain areas. Intensity exceeding 100mm/h, the threshold of 30mm/h, considered as a benchmark for intense precipitations was overcame 47 times.3. In June 2017 drought emergency was officially declared in the Piacenza and Parma provinces, due to the scarcity of precipitations since October 2016, coupled with high temperatures in Spring and early Summer. In hilly and mountain areas of Piacenza and Parma provinces, precipitation loss was estimated in 300-400 mm with respect to mean values referred to the period 1991-2015. Drought affected the whole region, as the scarcity of rainfall lasted nearly until the end of 2017, before the first snowfalls, but had peak effects in Piacenza and Parma provinces.To study the climate setting and effects of these hydrological extremes, interdisciplinary collaboration based on Climate and Earth Sciences was carried out by ARPAE- Servizio Idro Meteo Clima and Servizio Geologico, Sismico e dei Suoli of Emilia-Romagna Region. The results aim at matching applicative purposes, among them early warning, prevention and mitigation.Events were analysed in terms of geographic extent, classification of damages, monetary value of interventions. Studies on small mountain catchment basins were carried out for case 2, with highlights on case 1, evidencing both precipitation and geological-morphological preparing factors to mass transport of alluvial deposits. As fas as the case 3, attention is focused on the role of springs as early warning check-points, due to discharge variations recorded in the first stages of the 2017 drought, 3-4 months earlier than the emergency was declared. [ABSTRACT FROM AUTHOR]