Photogrammetry-Drone-Based Tool for Structural Vulnerability Assessment in Historic Urban Centers

This study presents the practical validation of a non-invasive method- ology for assessing the structural vulnerability of historic masonry buildings, pro- posed in the previous paper by the authors (see Part 1 of this volume) and based on photogrammetric data obtained using Unmanned Aerial Vehicles (UAVs). The method is tested on nine buildings in the village of Bova in Calabria, Italy. A drone survey is conducted to acquire high-resolution nadir and oblique images, which are then processed using Structure-from-Motion (SfM) techniques to generate tex- tured 3D models, orthophotos, and dense points clouds. Visually detectable param- eters, selected as significant for structural vulnerability assessment, are extracted directly from the photogrammetric outputs and used as input for a structured, Excel-based tool. Analytic Hierarchy Process (AHP) is used to weight the param- eters and Excel Visual Basic for Application (Excel-VBA), enables users to select responses for each parameter via dropdown menus. Internal automation then con- verts these selections into numerical scores. A vulnerability index is computed for each individual building, which is classified into three vulnerability levels.