Alessandro Sacchini

Environmental climatic maps of Liguria (Italy)

The Ligurian climate has been mapped for hydrological and tourist purposes. Isohyet and isotherm maps as well as ombrothermic diagrams show a great abundance of water characterizing the Ligurian environment. Winter and summer tourist maps, produced by running a global polynomial interpolation, highlight areas where climate allows snow tourism, coastal sports, bathing, relaxation and cultural tourism. A synthesis tourist susceptibility map shows many areas, often scarcely developed, where climate conditions are potentially suitable for the development of tourist activity.

Large-scale landslide and deep-seated gravitational slope deformation of the Upper Scrivia Valley (Northern Apennine, Italy)

The Scrivia river is a right tributary of the Po river, the main Italian water course, which flows eastwards into the Adriatic Sea. The head of the Scrivia valley is located in the Northern Apennines, a very short distance from the Ligurian Sea. Its catchment is characterized by landslide areas greater than both the regional and national average. In this work, the causes of this high landslide density have been investigated and a large-scale map of landslide phenomena is produced. Based on geomorphological constraints, several previously unknown deep-seated gravitational slope deformations (DSGSDs) were also identified. DSGSDs have been distinguished in sackungen and lateral spreads. Their characteristics were analyzed in a geographical information system (GIS) environment and compared with landslide distribution. Field surveys, aerial photo-interpretation and GIS analyses led to the production of a large-scale landslide and DSGSD overview map at 1:35,000. The massive presence of DSGSDs and their connection to landslide distribution and activity raise important implications for both geological mapping and land planning.

Yet another disaster flood of the Bisagno stream in Genoa (Liguria, Italy): October the 9th -10th 2014 event

On 2014, 9th October, short and heavy rainfall hit the Bisagno Valley. The Bisagno stream overflowed again and flooded the center of Genoa, causing severe economic damage and a victim. This is the fourth serious flooding of the stream in the last fifty years, which shows similarities with the previous catastrophic ones in 1970, 1992 and 2011, both because of the trigger conditions, determined by the orography of the city of Genoa, and for the weather situations marked by an anticyclonic block converging over the Liguria Gulf.Between 06:00 a.m. on October the 9th and 12:00 a.m. on October the 10th in the Bisagno catchment were recorded some peaks of rain up to almost 140 mm/h and heaps of more than 550 mm/24hrs, which resulted in a rapid increase in the level of all streams of the Bisagno basin and subsequent flooding in the final stretch of the Bisagno stream, where the watercourse underflows covered by a long manhole for the last 1.4 kilometres.Interventions for risk mitigation through more careful weather-hydrology monitoring in nowcasting, the improvement of the civil protection activities, structural works on the watercourse, maintenance of the territory of the Bisagno catchment, a correct information and a timely communication to the population living in high risk areas are all urgently needed.

Hydrogeology of conglomerate fractured-rock aquifers: an example from the Portofino's Promontory (Italy)

The Portofino promontory is characterised by springs supplying Camogli, Portofino and Santa Margherita Ligure towns. This research concerns a hydrogeological preliminary study of the Caselle springs, located in the San Fruttuoso valley at 325 m asl.Water circulation occurs in discontinuities of Portofino Conglomerate and has been investigated by scientific studies since the late Nineteenth Century. The flow of Caselle springs has been monitored, while the climatic parameters recorded in the Mount Portofino weather station have allowed a first comparison between rains and outflows.The hydrogeological water balance has allowed assessing a loss due to evapotranspiration of 627 mm and an outflow of 753 mm. The evaluation of the recharge area permitted to calculate outflows between 4 and 13 l/s: adopting an infiltration rate of 0.7, obtained infiltration values are comparable with the measured flow rates. The answer to the rains of hydrogeological parameters shows a ground-water velocity of 10-6 m/s; protecting the aquifer from potential sources of pollution is therefore deemed as essential, taking into account that over 80,000 hikers per year walk upon the recharge area.

Geological landscape and stone heritage of the Genoa Walls Urban Park and surrounding area (Italy)

ABSTRACT In the last 20 years the conservation and enhancement of cultural and landscape heritage sites have been increasingly promoted by specific national and international laws. Thematic maps from scientific studies facilitate the public promotion and understanding of landscape and cultural heritage. This work introduces a novel geological landscape and stone heritage map of the Genoa Walls Urban Park (1:10.000 scale). The park is located in the immediate surroundings of Genoa city centre and it includes a complex system of historical fortifications. Today the park is frequented by hikers, mountain bikers and tourists. The map shows three different elements of the park: lithological and geomorphological elements, cultural and landscape heritage sites and the trail network. This map offers new insights into the way in which the park authority can promote the sustainable fruition of a highly valuable area, characterised by landscape and historical interest next to one of the largest historical centres of Europe, part of which is inscribed in the list of Unesco World Heritage Sites.