Integration of LiDAR Data into a Regional Topographic Database for the Generation of a 3D City Model

To analyze the resilience of road infrastructures to natural and anthropic hazards, the spatial and descriptive data provided by the Italian National Topographic Data Base (NTDB) and the 3D data coming from the LiDAR data of the “Ministero dell’Ambiente e della Tutela del Territorio e del Mare” (MATTM) can be used. The two datasets, having different nature, need to be properly joined. The aim of the work is the integration of the two datasets in a GIS environment for the 3D modelling of the anthropized territory and the optimization of the cartographic bases. On a test area, crossed by a network of linear infrastructures of great strategic importance and subjected to hydrogeological risk, an automated process has been implemented and tested in ArcGIS Desktop environment, to homogenize the data into the National Reference System. The planimetric component comes from the NTDB whereas the LiDAR data have been used to attribute the elevation to the extracted elements, to create the breaklines for a proper interpolation of the heights to build the Digital Terrain Model (DTM), to extract the height of the pitches of the buildings identified in the NTDB polygons, and finally to generate, filter and optimize the contour lines. The proposed workflow and the methodologies implemented also allowed the reconstruction of the volumes of each element involved (infrastructures and buildings) and to correct the altimetric aberrations present in the NTDB polygons.