Assessment of physical vulnerability and potential losses of buildings due to shallow slides

Abstract

Physical vulnerability (PV) of buildings and associated potential losses (PLs) due to the occurrence of shallow slides are semi-quantitatively assessed at the regional scale in a municipality located in the North of Portugal. This work has four main purposes: (1) to identify and characterize the built environment exposed to shallow slides in the study area; (2) to assess the PV of each building type taking into account the building resistance (BR) and the landslide magnitude (LM); (3) to evaluate the economic value (EV) of each single exposed building using cadastral and market values; and (4) to estimate PLs on buildings due to landslide activity. The analysis is made for each single building of the study area, and this is an innovative contribution of this work. The semi-quantitative methodology to assess PV of buildings exposed to shallow translational slides combines the LM and the BR, which is empirically obtained weighting a set of parameters related to building characteristics. The quantification of the EV of buildings was carried out using an adaptation of the calculation formula used by the Portuguese Tax Services to determine the taxable value of buildings in Portugal. PLs result from the product between PV of the exposed buildings and their EV in euros. The overlapping of PLs of buildings with an available landslide susceptibility map, although does not provides any quantified risk analysis, provides valuable information to be used by spatial planning and civil protection stakeholders.