Marco Firpo

Geo-environmental cartography of the Marine Protected Area "Isola di Bergeggi" (Liguria, NW Mediterranean Sea)

Abstract Please click here to download the map associated with this article. Marine Protected Areas (MPAs) are considered one of the main tools for conservation, valorisation and management of coastal marine environments, and are defined by Italian Law (derived from European directives) as territories with “physical, geological, geomorphological and biological features having relevant naturalistic and environmental value”. While the bionomic mapping of MPAs has received large attention by researchers, MPA geological or geomorphological cartographies have been seldom realized. In this study we present a geomorphological cartography, comprising also environmental themes having a geomorphological significance, realized in the MPA “Isola di Bergeggi”.

Drones as tools for monitoring beach topography changes in the Ligurian Sea (NW Mediterranean)

The aim of this study was to evaluate topographic changes along a stretch of coastline in the Municipality of Borghetto Santo Spirito (Region of Liguria, Italy, north-western Mediterranean) by means of a remotely piloted aircraft system coupled with structure from motion and multi-view stereo techniques. This sector was surveyed three times over 5 months in the fall–winter of 2013–2014 (1 November 2013, 4 December 2013, 17 March 2014) to obtain digital elevation models and orthophotos of the beach. Changes in beach topography associated with storm action and human activities were assessed in terms of gain/loss of sediments and shifting of the wet–dry boundary defining the shoreline. Between the first and second surveys, the study area was hit by two storms (10–11 November 2013 and 21–22 November 2013) with waves approaching from the E–NNE, causing a shoreline retreat which, in some sectors, reached 7 m. Between the second and third surveys, by contrast, four storms (25–27 December 2013, 5–6 January 2014, 17–18 January 2014 and 6–10 February 2014) with waves propagating from the SE produced a general advancement of the shoreline (up to ~5 m) by deposition of sediments along some parts of the beach. The data also reflect changes in beach topography due to human activity during the 2013 fall season, when private beach managers quarried ~178 m3 of sediments on the emerged beach near the shoreline to accumulate them landwards. The results show that drones can be used for regular beach monitoring activities, and that they can provide new insights into the processes related to natural and/or human-related topographic beach changes.

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.

Coastal and marine geomorphology between Albenga and Savona(NW Mediterranean Sea, Italy)

In this paper, we present a map describing the main geomorphological features of the coastal and marine area between the towns of Albenga and Savona (Ligurian Sea, NW Mediterranean) corresponding to a coastal stretch of ∼40 km. To produce this map, we collated data from the literature, orthophotos, perspective photos, multibeam and side scan sonar data, and undertook direct surveys to ground truth data obtained using indirect techniques. We divided the information into nine thematic layers, including bathymetry, natural coastal types, geomorphological elements, seafloor coverage (both geological and biological), coastal and nearshore dynamics, human influence on coastal and marine environments, coastal occupation and protected areas.

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.

Petroplinthite formation in a pedosedimentary sequence along a northern Mediterranean coast: from micromorphology to landscape evolution

PurposeThe petroplinthic horizon is a layer of indurated material in which Fe is an important cement, and it pertains to the pedogenetic material called “laterite”. The aim of this paper is to document the evolution of a coastal pedosedimentary sequence that developed in NW Italy during the Quaternary and discuss the genesis of its petroplinthic horizon within the context of environmental changes that should not have been favourable to lateritisation processes.Materials and methodsThe palaeosol profile was described, and the soil horizons were grouped into pedostratigraphic levels. The horizons were characterised using laboratory routine analysis, X-ray diffraction and thin section micromorphology. In addition, a scanning electron microscope examination of the back-scattered images and an elemental analysis were performed on the petroplinthic horizon only.Results and discussionThe micromorphological evidence and mineralogical analyses suggest a polygenetic origin for the profile that reflects the influence of separate processes acting on distinct parent material under different environmental conditions.ConclusionsThe petroplinthic horizon results from a pedogenetic process that occurs during seasonal fluctuations of the water table, whereas the plinthite has no pedogenetic link with the weathered bedrock. The plinthitisation/ferrugunisation derived from iron enrichment and accumulation from an external upslope source and/or by post-depositional precipitation of “secondary” iron phyllosilicates (e.g. hisingerite) is a result of the dissolution of pre-existing hematite in inherited detrital laterite fragments.

Evolution of an Upper Pleistocene aeolianite in the northern Mediterranean (Liguria, NW Italy)

Based on a 19th century scientific report, a recent geological survey has highlighted the presence of a complex, mostly Aeolian deposit along the coast of Liguria (Laigueglia, Savona Province, NW Italy). This finding was recognized to be a relevant palaeoclimatic marker, being the northernmost aeolianite outcrop ever reported from the Mediterranean Basin. The investigated deposit is spread along a steep sea-facing slope from 2-3 m up to almost 60 m a.s.l.; it is strongly reworked due to recent urbanization of the area. Its stratigraphic features were recognized thanks to its exposure in different sections and analysed in order to obtain reliable indications on the sedimentary environments. Facies analysis suggests that the sedimentary body is a relict cliff-top dune evolved on top of a foreshore deposit in temperate-cold and moist climate conditions. Two samples from the upper, strictly aeolian part of the sequence were subjected to OSL (Optically Stimulated Luminescence) dating and yielded an age consistent with its deposition during the Marine Isotopic Stage (MIS) 5.2 and 5.1 substages (88-83 and 83-71 ka). This paper contributes to the increase of the number of Upper Pleistocene coastal aeolianites accounted for in literature. Being located at the northern border of the occurrence of aeolianites in the northern Mediterranean, it helps to outline climatic and environmental boundary conditions for the formation of this type of deposit.

Geo-hiking map of Mt. Penna and Mt. Aiona area (Aveto Natural Park, Italy)

This work presents a geo-hiking map of Mt. Penna and Mt. Aiona area (Aveto Natural Park, Italy), an original and useful tool in the Earth science mapping field. Aveto Park is one of the best known Italian protected areas; it is located in the Ligurian Apennines and belongs to the Ophiolitic Protected Areas Coordination (‘C.A.P.O.’) and to the European Ecological Network Nature 2000. The Park area is crossed by more than 500 km of paths and trails where hikers, climbers and mountain lovers walk every year. The geo-hiking map was compiled by combining available geological and geomorphological bibliographic data with a field survey and basic information derived from hiking and tourist maps. The main stages used for production of the map are as follows: (a) bibliographic and map research of scientific papers; (b) a geological and geomorphological field survey; (c) trail and route data from tourist park maps; (d) research of geotouristic elements of interest. This work shows an example of geocartography research that really contributes to the implementations of documents and maps useful in the hiking tourism field. The main map is complemented with a natural hazard map; increasing tourism during the whole year in areas with geomorphological hazards results in a relationship between the human element, natural processes and hazard phenomena.

Landslide Inventory of the Cinque Terre National Park, Italy

Landslide inventory maps are effective and easily understandable products both for experts, such as engineering geologists, and for nonexperts, including decision-makers, planners, and civil protection managers. At present, the Cinque Terre landscape suffers from the massive abandonment of cultivations on the terraces, with negative consequences for slope stability due to the increasing erosional processes. Each landform was digitized as a polygon using a GIS platform. Landslide detection was performed by a two-step method. The first step consisted of mapping landslides using orthophotos provided by Liguria Region, together with Google Earth imagery; the second step was a field verification study carried out between September and November 2015. Four hundred and five landslides were then identified and grouped into seven main typologies: a percentage distribution analysis of the different landslide types detected in Cinque Terre was then performed. A large number of debris slides (33.3%) indicates the vulnerability of dry-stone walls after large amounts of rainfall. Rockfalls (18.5%) are also frequent and especially concentrated along the eastern sector of the coastline. In addition, debris flows (12.6%) are widely distributed, especially along the western sector of Cinque Terre, among the Monterosso and Vernazza municipalities; these landslides were mainly triggered by the October 25th, 2011, meteorological event (382 mm of rainfall in 24 h recorded by the Monterosso al Mare weather station). Many landslides with complex evolutions (7% of the total) were detected along the coastline between Vernazza and Manarola; these events are historically well-known and extensively described in the literature.

Extreme Flood and Landslides Triggered in the Arroscia Valley (Liguria Region, Northwestern Italy) During the November 2016 Rainfall Event

From November 20th, 2016, to November 25th, 2016, Liguria Region (northwestern Italy) experienced prolonged and intense rainfall. The rainfall sequence occurred following two main phases. The second phase mainly hit the western sector of the region, reaching its peak on November 24th. Rainfall was particularly abundant within the Arroscia valley, where the 5–days cumulative rainfall locally exceeded 50% of the mean annual precipitation. In this paper, we document the rainstorm magnitude, presenting a first inventory of the rainfall–induced ground effects within the Arroscia Valley. The mapping was performed by means of extensive field work that was partly supported by satellite imageries. More than 250 landslides affected the upper sector of the valley, while in the downstream reach, widespread flood-related forms and processes resulting from the abundant precipitation were mapped. The results of this study are expected to be helpful for future research on both landslide– and flood–related channel change susceptibility and risk scenarios evaluation.