Role of rainfall intensity and urban sprawl in the 2014 flash flood in Genoa City, Bisagno catchment (Liguria, Italy)

The Bisagno stream catchment (Genoa, Italy) and its major floods: geomorphic and land use variations in the last three centuries

The aim of this study is to demonstrate the advantages of using micro drones in the study of large slow-moving landslides, which are widespread along the northwestern coast of Malta. In particular, attention was given to the inventory and analysis of gravity-induced joints and megaclast deposits at four study sites selected due to the presence of remarkable examples of lateral spreads evolving into block slides. The research was carried out by means of Google Earth (GE) image analysis and uncrewed aerial vehicle digital photogrammetry (UAV-DP). UAV-DP outputs enabled the identification and characterization of tens of persistent joints (locally exceeding 150 m) and permitted the size categorization of thousands of blocks. With reference to gravity-induced joints, a favorable agreement was found between existing datasets (mainly based on the integration of GE analysis and field survey) and UAV-DP outputs in terms of the identification of joints and their persistence. Conversely, the use of the UAV-DP technique showed significant advantages in terms of joint aperture determination (even exceeding 1 m) and distribution setting. Regarding the extensive megaclast deposits, UAV-DP enabled the identification of 8943 individuals which, compared with the 5059 individuals identified by GE analysis, showed an increase in the total population of 76%. This is related to the high accuracy of DP-derived orthomosaics and 3D models, which are particularly useful for identifying detached blocks. The inexpensive technique used in this research highlights its potential for being extended to other rocky coastal areas affected by slow-moving landslides.

Advantages of Using UAV Digital Photogrammetry in the Study of Slow-Moving Coastal Landslides

We present new data about the morphological and stratigraphic evolution and the rates of fluvial denudation of the Tavoliere di Puglia plain, a low-relief landscape representing the northernmost sector of the Pliocene-Pleistocene foredeep of the southern Apennines. The study area is located between the easternmost part of the southern Apennine chain and the Gargano promontory and it is characterized by several orders of terraced fluvial deposits, disconformably overlying lower Pleistocene marine clay and organized in a staircase geometry, which recorded the emersion and the long-term incision history of this sector since mid-Pleistocene times. We used the spatial and altimetric distribution of several orders of middle to late Pleistocene fluvial terraces in order to perform paleotopographic reconstruction and GIS-aided eroded volumes estimates. Then, we estimated denudation rates on the basis of the terraces chronostratigraphy, supported by published OSL and AAR dating. Middle to upper Pleistocene denudation rates estimated by means of such an approach are slightly lower than 0.1 mm yr-1, in good agreement with short-term data from direct and indirect evaluation of suspended sediment yield. The analysis of longitudinal river profiles using the stream power erosion model provided additional information on the incision rates of the studied area. Middle to late Quaternary uplift rates (about 0.15 mm yr-1), calculated on the basis of the elevation above sea level of marine deposits outcropping in the easternmost sector of the study area, are quite similar to the erosion rates average value, thus suggesting a steady-state fluvial incision. The approach adopted in this work has demonstrated that erosion rates traditionally obtained by quantitative geomorphic analysis and ksn estimations can be successfully integrated to quantify rates of tectonic or geomorphological processes of a landscape approaching steady-state equilibrium. Copyright © 2014 John Wiley & Sons, Ltd.

Landscape response to tectonic and climatic forcing in the foredeep of the southern Apennines, Italy: insights from Quaternary stratigraphy, quantitative geomorphic analysis, and denudation rate proxies

The coastal landscape of the Maltese Islands is the result of long-term evolution, influenced by tectonics, geomorphological processes, and sea level oscillations. Due to their geological setting, the islands are particularly prone to marine-related and gravity-induced processes, exacerbated by climate change. This study aligns different concepts into a relatively concise and expedient methodology for overall coastal vulnerability assessment, taking the NE sector of Gozo Island as a test case. Geomorphological investigation, integrated with analysis of marine geophysical data, enabled characterization of coastal dynamics, identifying this stretch of coast as being potentially hazardous. The study area features a high economic value derived from tourist and mining activities and natural protected areas, that altogether not only make coastal vulnerability a major concern but also the task of assessing it complex. Before introducing the methodology proposed for overall vulnerability assessment, an in-depth revision of the vulnerability concept is provided. The evaluation was carried out by using a set of key indicators related to local land use, anthropic and natural assets, economic activities, and social issues. Results show that the most critical areas are located east of Marsalforn including Ramla Bay, an important tourist attraction hosting the largest sandy beach in Gozo. The method combines physical exposure and social vulnerability into an overall index. It proves to be cost effective in data management and processing and is suitable for the identification and assessment of overall vulnerability of coastal areas to consequences of climate- and marine-related processes, such as coastal erosion, landslides and sea level rise.

https://www.mdpi.com/2073-4441/12/5/1405/pdf

Coastal vulnerability assessment along the north-eastern sector of Gozo Island (Malta, Mediterranean Sea)

This paper introduces a novel geoheritage map of the Portofino Natural Park. The park is an internationally well-known area, protected since 1935, located in the Ligurian Apennines, 25 km E of Geno...

https://www.tandfonline.com/doi/pdf/10.1080/17445647.2018.1433561

Geoheritage map of the Portofino Natural Park (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 connecti...

https://www.tandfonline.com/doi/pdf/10.1080/17445647.2015.1021393

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

This paper presents an integrated geomorphological map of terrestrial and marine areas of northern Malta and Comino (central Mediterranean Sea) at 1:25,000 scale The map is the result of terrestrial and marine analyses of different types of data such as aerial photos, digital terrain model of the seafloor and its acoustic backscatter image The research is intended to emphasise the relationships and continuity of geomorphological features of both the land- and sea-scape, and outline their evolution The map highlights the occurrence of fluvial, karst and gravity-induced landforms both on land and on the seafloor, such as palaeo-fluvial channels, sinkholes and landslides, which were shaped during sea level lowstands of the last glacial cycle

https://tandfonline.com/doi/pdf/10.1080/17445647.2017.1327507

Geomorphological mapping of terrestrial and marine areas, northern Malta and Comino (central Mediterranean Sea)

The Tavoliere di Puglia is a large alluvial plain located in southern Italy (Foggia Province, Apulia Region). From a geological perspective view, it represents the northern part of the Bradanic trough located between the southern Apennine Chain and the Apulian Foreland. A detailed geological survey of the middle-late Pleistocene terraces has been performed in this area and a new geologic map, at 1:150,000 scale, is here described. Criteria to distinguish these units are based on the recognition of basal unconformity surfaces: seven different synthems (UBSU, Unconformity-bounded Stratigraphic Units) have been discriminated. The data are presented in a synthesis map in which the geometrical relationships between the different sedimentary units are shown. New results for this sector of the Bradanic trough are significantly different from previous literature data. Furthermore, the map allows a reliable reconstruction of the Tavoliere di Puglia paleogeography during the Late Quaternary. Moreover, a detailed ma...

Geology of the middle and upper Pleistocene marine and continental terraces of the northern Tavoliere di Puglia plain (Apulia, southern 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...

https://www.tandfonline.com/doi/pdf/10.1080/17445647.2012.668756

Serafino Angelini

Papers

Geoheritage map of the Portofino Natural Park (Italy)

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

Geomorphological mapping of terrestrial and marine areas, northern Malta and Comino (central Mediterranean Sea)

Geology of the middle and upper Pleistocene marine and continental terraces of the northern Tavoliere di Puglia plain (Apulia, southern Italy)

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