The ‘Deluge’ of 25 October 1822 in Genoa, Italy

Due to meteorological, geomorphological, and urban landscape features, the city of Genoa is frequently exposed to hydrological instability. Historical sources refer to floods since the early Middle Ages, while in the last few years the most impactful events with human losses took place in 2010, 2011 and 2014. Two centuries since its occurrence, using written reports, iconographical material and scientific reconstructions, the paper examines the flood of Genoa of 25 October 1822. In terms of rainfall data, surface effects and dynamics, this flood was one of the most destructive events of the city’s history

Urban geomorphology of a historical city straddling the Tanaro River (Alessandria, NW Italy)

The integration of \ufb01eld surveys, bibliographic research and multitemporal analysis of historical maps, aerial photographs and satellite images in a GIS environment, allowed the current and past geomorphological features of the old city of Alessandria and its surrounding areas, NW Italy, to be identi\ufb01ed and mapped. Their analysis provided an overview of the geomorphological evolution of the city that is strictly related to the historical vicissitudes occurred since the Middle Ages. Nowadays, the most representative landforms and deposits characterizing the urban landscape result from human interventions and are associated with ancient military facilities and infrastructures, a historical man-made channel network no longer recognizable, the Tanaro riverbed channelization, and the urban sprawl occurred from the second half of the nineteenth century onwards. This study represents a useful tool for urban planning and management and for raising the citizens\u2019 awareness of the urbanlandscape geomorphological features and evolution, and therefore the geo-hydrological risk

Engineering geological map of the Chiavari city area (Liguria, Italy)

An engineering geological map at a scale of 1:10,000 of the Chiavari city area (Northern Italy) – a major tourist and economic attraction of the Ligurian East Riviera – is presented in this paper. The municipality land shows an excellent geomorphological case-study of the well-known Ligurian coast: a floodplain, fairly wide and inhabited, formed by several floods of the two main rivers, a hill hinterland, reasonably inhabited, developed in marly limestones and sandy shales flysch and the coast – featuring cliffs and narrow pebbly beaches – deeply modified. This map was compiled by combining available geological data with a new engineering geomorphological field survey and including geotechnical data which were obtained from studies carried out for town planning and building purposes. On the basis of the critical review of the available lithostratigraphic data from drilling, as well as geotechnical and geophysical analyses carried out between 1981 and 2010 on the municipality land, an engineering geologica..

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

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\u2019s I statistics and spatial local autocorrelation; a Mann\u2013Kendall trend test was performed on monthly series aggregating the original data on a 5 7 5 km cell. A local statistically significant trend emerged from the analysis, suggesting possible linkage between surface warming and lightning activity

Hindcast high-resolution simulation of the most catastrophic rainfall event in Genoa City (7-8 October 1970): hydro-meteorological and geomorphological analysis

Liguria region is historically affected by severe hydro-meteorological events often resulting in dramatic death tolls and large socio-economic impacts. On 7-8 October 1970, Genoa, region capital city, was struck by the most catastrophic flood event of its history. On the evening of 7 October pre-frontal storms affected the western side of the city (Voltri, Prà and Pegli municipalities), while on 8 October 1970 an anticyclone block generated recurring convective systems that hit Genoa city and above all the Bisagno Valley. The heavy rainfall continued more than 24 h with highs at Bolzaneto rain gauge (Polcevera Valley, northwest of Genoa city center) where over 950 mm of rainfall in 24 hours was measured. Over the city center and the Bisagno Valley, 400 mm in 24 h was recorded. The Bisagno stream channels overflowed, submerging the city center. The 1970 event in Genoa City was also the most dramatic in terms of damage: 44 fatalities occurred and over 2000 individuals were evacuated. This study hindcasts the meteorological evolution of this event at high spatial resolution (1.5 km) and temporal one (1 hour) using the Weather and Research Forecasting (WRF) model by downscaling the ERA5 climatology developed by European Center for Medium-Range Weather Forecast (ECMWF). The weather hindcast scenario is compared with available meteorological observations as well as with recorded geomorphological impacts on Genoa city center and municipalities

Heatwaves and physiological discomfort: the strange case of the year 2022 on the ‘Kiss Pass’ of Portofino Natural Park, Italy

Due to its cultural and landscape attractions, Portofino Natural Park is walked by thousands of hikers per year. In the Park's trail network, the path between Batterie and San Fruttuoso (known as “Passo del Bacio” translated to “Kiss Pass”) is one of the most popular because it is located on the edge of high rocky cliffs. Due to slope exposure and meteorological features, interventions by National Corp of Alpine and Speleological Rescue occur annually. The year 2022 was a record year, either for the particularly warm meteorological profile and the exceptional number of accidents recorde

Urban geomorphology of Genoa old city (Italy)

Field survey and geomorphological mapping in urban areas are difficult tasks, particularly those related to the recognition of natural landforms within cities. In this case, it is necessary to apply an integrated scientific approach by combining geomorphology with historical-geography. This paper presents the result of a multi-year survey carried out in the natural morphological amphitheatre where the historic centre of Genoa developed. Our research methods included field surveys in urban areas, interpretation of natural and anthropic landforms from maps and photographs, and analyses of the available borehole logs. As a result, we updated knowledge on urban geomorphology of Genoa old city. An original geomorphological legend has been adopted, including new entries for anthropogenic landforms, targeted at a better visual representation on the changes in the geomorphological landscape during more than one thousand years of urban development of the city. The geomorphological map of Genoa old city is presented as a useful tool for urban planning, as well as for an integrated cultural and landscape enhancement of the territory

Exposure\ua0to\ua0Geo\u2010Hydrological\ua0Hazards\ua0of\ua0the\ua0 Metropolitan\ua0Area\ua0of\ua0Genoa,\ua0Italy:\ua0A\ua0Multi\u2010Temporal\ua0 Analysis\ua0of\ua0the\ua0Bisagno\ua0Stream\ua0

Geo\u2010hydrological  risk  reduction  policies  are  becoming  a  critical  challenge  for  environmental sustainability, both at the national and international levels. The reason is twofold:  On the one hand, climate change has increase rainfall frequency and intensity, while on the other,  reckless urban expansion has increased exposure to such hazards over time. Italy is a country that  is very vulnerable to flood and landslide hazard; the city of Genoa, which, in recent decades, has  been frequently hit by severe floods, has risen to symbolize Italian geo\u2010hydrological risk. Recent  studies  on  Genoa\u2019s  geo\u2010hydrological  hazard  have  focused  on  the  analysis  of  hydrogeomorphological features of the Bisagno stream basin, yet their main focus was on hazard control.  Very little research has been done to enhance the understanding of the source of risk in such  catchments. This paper presents a study on the increased urban exposure and vulnerability to geohydrological hazard along the Bisagno stream catchment area over the last 200 years. Morphometric  analyses were coupled with historical documents showing the evolution of the urban layout in this  area. The results show that the \u201cBisagno Master Plan\u201d, a territorial planning strategy aimed at  reducing geo\u2010hydrological hazard and risk, has not produced the expected benefits. In spite of the  plan,  critical  changes  in  land  use  and  the  hydrographic  network,  along  with  uncontrolled  anthropization of the Genoa metropolitan area, has continued over the last two decade