## 1 Introduction
Although some authors have implemented and published software systems to store and visualize subsoil data to be used in seismic microzoation [31], to the best of our knowledge no databases or WebGIS tools relating to soil-building interaction in urban areas have currently been made public. The soil-building resonance effect is a well-known and extensively studied phenomenon. It can arise during seismic events when the oscillation frequency of a building is very close to that of the foundation soil, causing an increase in damage [32; 33; 34; 35]. The soil-building interaction effect for a single/limited number of closed-spaced buildings has been numerically and experimentally studied [36; 37; 38; 39], while for the urban scale as a whole only numerical simulation approaches have been proposed [33; 40; 41; 42; 43; 44; 45; 46]. Recently, [PERSON] et al. (2020) [47] evaluated the probability of resonance effect in several districts of municipalities of Alicante and Elche, while other authors have produced soil-building resonance level maps based on numerical relations provided by seismic regulations [48; 49], and on extensive collections of experimental data [8]. From a legislative point of view, microzonation studies focus exclusively on the seismotectonic, lithost stratigraphic, and geotechnical aspects of shallow soil, completely neglecting the presence and role of buildings [8]. Thanks to seismic microzonation studies, it is possible to know the exact areas susceptible to seismic amplification and instabilities; however, there is no information about areas of cities where the soil-building resonance effect could take place during earthquakes. In this paper, an open tool with the dual function of a geodatabase and disseminative WebGIS, through which it is possible to visualize and download (i) geological, geotechnical, and geophysical data; (ii) the spatial distribution of the main resonance frequency for urban soils; (iii) the main vibrational frequencies for the 4043 overlying buildings; (iv) the spatial distribution of the soil-building resonance levels for the urban area of Matera, which represents the innovative core is presented. Therefore, for the first time, the urban environment has been seismically characterized as a unicum (urban subsoil and overlying buildings), and all data are fully usable through CLARA WebGIS. In addition, users can also rely on a Digital Surface Model (DSM) of the city of Matera and its surroundings, which was generated with a cross-sensor multi-view approach from a triplet of optical satellite images. DSMs, which incorporate the natural ground surfaces, buildings, vegetation, and other objects higher than the underlying topographic surface [50,51], can serve as valuable input for the characterization of urban structures. In this way, DSMs address the requirement of municipalities for reliable and up-to-date information for land-use and infrastructure planning, the creation and continuation of development plans, and the overall monitoring of changes [52]. The increasing availability of new high-resolution optical spaceborne sensors allows for the creation of precise DSMs (such as the one included in the CLARA WebGIS), ensuring low cost, speed of data acquisition and processing, and relaxed logistic requirements [53]. A detailed presentation of the experimental design and the methodology adopted to produce the soil-building resonance map and to generate the DSM can be found in [PERSON] et al. (2020) [8] and [PERSON] et al. (2021) [54], respectively.