## 2 CLARA WebGIS: Data Sources
### CLARA Data  
#### 2.3.1 Ground-Based Geophysical Data  
In the framework of the CLARA project, the interaction effect between near-surface geology and all overlying buildings in the urban area of the city of Matera, as thoroughly described by [8], was evaluated. To this end, 107 single-station seismic ambient noise measurements of the main urban lithologies and 62 of the main building typologies were planned and performed. All the seismic ambient noise recordings on soils and buildings were performed using a Tromino seismograph (MoHo s.r.l.) and were analyzed applying the Horizontal-to-Vertical spectral ratio technique (HVNSR), following the standard procedures [58; 59; 60] and using Grilla software (version 8.1, Moho s.r.l. 2018). It was possible to estimate the main resonance frequencies for all urban soils and the main vibrational frequencies for the measured buildings. Figure 2: Spatial distribution of STAT census variables aggregated by neighborhood and classified according to (**A**) number of total buildings; (**B**) population; (**C**) number of residential buildings, including a pie chart of (**A**) building state of conservation, (**B**) building use, (**C**) built typology. The integration of the 107 new and 10 pre-existing HVNSR (Table 1) curves evaluated for urban soils increased the area of the city of Matera covered by surveys from 18 to 1758 ha, with an average density of 3.7 surveys/km\({}^{2}\). Overall, the density of all surveys in the urban area is about 11.25 surveys/km\({}^{2}\). We merged in the same point-vector layer, named 'HVNSR soil', the pre-existing and new HVNSR functions. By clicking with the hand icon cursor on the point of interest, it is possible to visualize a factsheet with all the information related to that point (Figure 4). The thirteen fields shown in the factsheet have been given self-explanatory names: 'X' and 'Y' report the coordinates or the measurement locations in UTM WGS84 33N, EPSG 32633; 'A_Thresold' is the value of the HVNSR amplitude beyond which amplification is considered to occur (this value was chosen to be equal to 2 for all the analyses; [PERSON] et al., 2020 [8]); 'F0 soil' is the value of the soil  
Figure 3: Examples of factsheets displayed by clicking on the related geometries (polygon in **F** sub-image) or symbols (upper right corner of single sub-images **A**–**E**) and examples of downloadable files of pre-existing geological/geotechnical/geophysical surveys for (**A**) downhole; (**B**) seismic refraction survey; (**C**) mechanical survey; (**D**) MASW; (**E**) calcarenite sampling station; (**F**) geological map. fundamental resonance frequency (Hz), with an amplitude equal to 'A0 soil'; 'F1 soil' (<'F0 soil') and 'F2 soil' (>'F0 soil') are the two frequencies (Hz) at which the HVNSR curve intersects the 'A_Threshold' value; 'Data_asc' and 'Data_bmp' contain hyperlinks to the downloadable HVNSR file in text format and HVNSR curve in bmp format, respectively; 'Macro area' indicates the neighbourhoods whose names are untranslatable, except for 'Historic Center' ('Centro Storico') and 'Small business area' ('Zona Artigianale') [61]. By integrating the 34 pre-existing with the 62 new HVNSR functions estimated for buildings, the percentage of buildings measured increased from 0.8% (#6) to 2.5% (#18) for masonry buildings (out of 732) and from 1.5% (#28) to 4.2% (#78) for reinforced concrete buildings (out of 1872). The percentage was calculated with respect to the total number of buildings falling within the studied area (#2648) for which the building typology was known. For reinforced concrete buildings, the sample distribution of measured buildings by macro-area is representative of the percentage of buildings in that area with respect to the total number of buildings in the urban study area (Figure 5B,C). The same does not apply for masonry buildings (Figure 5D,E) due to logistical issues (impossibility of access, etc.).