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This work is part of a broader project that aims to define a methodology for assessing the local seismic response on a large scale through a series of cognitive phases. Here we present the first phase that illustrates a procedure for the creation of standardised geothematic maps, at a national, regional and sub-regional scale, showing the geological and engineering-geological features that potentially induce stratigraphic amplification of the ground seismic motion. The main goal is to create a national reference legend to adopt, at different scales and detail, for complete coverage of the national territory. The method consists of consecutive steps that can be followed to obtain more detailed documents, starting from national scale geological maps, taking into account all the possible geological contexts characterising the Italian Peninsula. The first step is the reclassification of the lithostratigraphic units from the most detailed, reliable and updated available geological maps, in order to compose homogeneous geological and engineering geological maps at national scale. The construction of the legend and the elements contained in it plays a fundamental role in the process and constitutes the reference for more detailed maps at larger scales. We consider the age and the genetic domain to identify 10 main geological categories and from these, considering the prevailing lithological characters, to distinguish 27 geological groups. The engineeringgeological map at national scale derives from the combination of the geological groups with the engineeringgeological groups, representing the main characters of the cover terrains on the base of the main grain size and the geological substratum categories, adopted in the seismic microzonation studies (Technical Commission for Seismic Microzonation, 2020). At regional and sub-regional scale, we reclassified a more detailed geological map to convert it in an engineering-geological map of territorial context, characterised by the engineering-geological units adopted in the seismic microzonation studies of Italy. In order to reconstruct all the possible stratigraphic columns in term of the engineering-geological units in the territorial context representative of the shallower subsoil (< 50 m in depth), we proposed a representation in matrix form that combines the outcropping engineering-geological units with the units of the subsoil. Where seismic microzonation studies are not available, the multiscale engineering-geological maps could represent a useful tool for the seismic hazard assessment for the territorial planning at regional and sub-regional scale. Furthermore our results will be able to use the data of dynamic parameters (i.e., the shear wave velocity Vs) stored in DB-SM (National Seismic Microzonation Database, www.webms.it), in order to characterise the engineering-geological units of the reconstructed successions. Despite the different observation scales of the national SM project, the proposed methodology can provide rules for applying the SM standards with the aim of carrying out a "review" of the studies already completed and directing those in the implementation phases towards homogeneity. At international level this methodology could be taken as a reference for planning SM studies.

Seismic liquefaction assessment at different geographical scales provides hazard maps at increasing levels of resolution and reliability. According to the considered level, the areas prone to liquefaction are identified based on specific predisposing and triggering factors, including geological and geotechnical subsoil properties and local seismicity. The robustness of the definition of these areas is strongly correlated to the availability and spatial distribution of this information. Moreover, the data type and quality considerably influence the method of analysis and the degree of uncertainty of the results. This work proposes a methodological approach to define maps in terms of liquefaction susceptibility at two different geographical scales (i.e., regional and sub-regional scale). The Calabria region in Southern Italy was studied for the scope, characterised by a relatively high level of seismicity and liquefaction occurrences recorded during the numerous historical earthquakes. At the regional scale, the level of zonation represents a preliminary assessment of areas potentially susceptible to liquefaction. The considered predisposing factors and geospatial variables were implemented from approximately 5520 available surveys, using geostatistical tools to filter inconsistent data and quantify uncertainties. A quantitative assessment of the liquefaction predisposition was also proposed at a sub-regional scale in the identified areas prone to liquefaction. A new proposal of a Territorial Liquefaction Predisposing Index was carried out by quantifying the uncertainty due to the limited availability of data with geostatistical methods. This approach could provide helpful information for land management and emergency planning to characterise the territory for liquefaction instability and optimise resources allocation to reduce the level of uncertainty at higher levels of analysis.