Geology and mass movements of the Licetto River catchment (Calabrian Coastal Range, Southern Italy)

<p>The paper presents a detailed mass movement inventory map of the Licetto River basin, an intermountain catchment of 50 km² formed during the Quaternary in response to extensional tectonics dissecting fold-and-thrust belts of the Calabrian Coastal Range (Southern Italy). The map (Main Map) is the result of both an integration between geological and morphological data derived from the visual analysis of aerial photographs at different times and scales, and the collection of new data obtained from multi-temporal field surveys. The study area is affected by a total of 824 mass movements, frequently made by superimposed bodies of different types, states of activity and sizes, including some kilometre-scale Deep-Seated Gravitational Slope. The majority of the mapped landslides, mainly of slide type, involve low-grade metamorphic rocks which also show the exclusive presence of deep-seated gravitational slope deformations. Analysis of the inventory map revealed that 40% of the mapped landslides, often attributable to very slow-moving landslides, can be considered active. The Main Map represents a useful tool for territorial planning and engineering – geological and environmental purposes in this complex geo-structural area, providing a useful contribution for quantitative landslide risk analyses and the design of appropriate risk-mitigation measures.</p

Weathering grade and geotectonics of the western-central Mucone River basin (Calabria, Italy)

<p>This paper illustrates the compilation of an engineering geological map based on structural architecture and weathering grade of crystalline rocks occurring in the central-western portions of the Mucone River basin (Sila Massif, Calabria, Italy). The map, drawn at 1:10,000 scale and covering an area of about 100 km², was compiled by combining new geological and structural data with the results of a weathering-grade field survey. Five weathering classes, each characterized by comparable mechanical behaviour, have been mapped, from the class VI (residual and colluvial soils) to class II (slightly weathered rock). Both qualitative and semi-quantitative criteria (e.g. rock colour, discolouration processes, samples broken by hand and hammer, sound of the rock when it is struck by a geological hammer, Schmidt Hammer tests) were used to distinguish and map weathering-grade classes at outcrop scale.</p> <p>The thematic map presented in this paper aims to provide a useful tool for land planning policy, for the evaluation of geological and geotechnical hazard and for environmental and engineering perspectives of land use.</p

Landslide inventory map of north-eastern Calabria (South Italy)

<p>Landslides are one of the most widespread natural hazards in many areas of Calabria region (Southern Italy), due to the combination of its peculiar geological, morphological, and climatic characteristics and very often to unsustainable land management. This study reports the reconnaissance and the characterization of landslides of north-eastern Calabria (south Italy). The landslide inventory map was obtained by combining field surveys with the analysis of topographic maps and multi-temporal air photos, taken in the period ranging from 1954 to 2006. This analysis has provided the spatial and temporal evolution of mass movements. The integration and elaboration of the data obtained in a GIS environment provided the inventory map of landslides on a scale 1:50,000. Landslides are widespread in the study area and play an important role in the present-day landscape evolution. A total of 1003 landslides were recognized, occupying a surface of 230.4 km², about 30.5% of the whole study area. The landslides were mapped on the basis of the movement type, as follows: slides, flows, falls and complex landslides. Slide and complex type mass-movements are very common, and represent more than 87% of the landslides mapped. The pelitic lithologies show the highest density of landslides, mainly complex type. Multi-temporal air photo interpretation and field surveys provided data for distinguishing the state of activity of the landslides; therefore, 29% of the landslides mapped has been assessed active while the remaining 71% has been considered inactive. This kind of map is an useful tool for land planning policy. As all the data are digitized and stored in GIS database, this will provide the basic input needed to generate the landslide susceptibility assessments besides evaluate the landslide hazard and risk.</p

Seismotectonics and landslides of the Crati Graben (Calabrian Arc, Southern Italy)

<p>The Crati Graben is a depression of Plio-Holocene age mainly controlled by extensional N–S striking faults and WNW–ESE transcurrent faults, in its northern and southern extremity. It is characterized by high landslide susceptibility due to the particular geo-structural pattern and seismotectonic characters. Landslides involve many villages, infrastructure and food crops, bringing serious economic and social damage. The seismotectonic and landslides <a href="http://dx.doi.org/10.1080/17445647.2016.1223760" target="_blank">Main Map</a> of the Crati Graben, described in this paper, represents an update in detail of the framework of landslide risk areas and shows the main active and recent faults of the Crati Graben. The landslides and the faults, have been identified and classified, originally at detail scale (1:5000) and, then, represented at 1:50,000 scale. The geo-structural and geomorphological data were analysed in a geographic information system. The work has revealed a correlation between the trend of faults with respect to the distribution of landslides and of the historical and instrumental seismicity. The work presents an updated knowledge framework of risk conditions of the study zone, where risk areas related to slope instability are hierarchically classified according to the destructive potential of landslides. This document may be therefore a useful reference in planning and prioritising in the design of interventions for the safety of slopes and waterways.</p