Articles | Volume 16, issue 2
https://doi.org/10.5194/nhess-16-311-2016
https://doi.org/10.5194/nhess-16-311-2016
Research article
 | 
03 Feb 2016
Research article |  | 03 Feb 2016

Assessment of physical vulnerability of buildings and analysis of landslide risk at the municipal scale: application to the Loures municipality, Portugal

C. Guillard-Gonçalves, J. L. Zêzere, S. Pereira, and R. A. C. Garcia

Abstract. This study offers a semi-quantitative assessment of the physical vulnerability of buildings to landslides in a Portuguese municipality (Loures), as well as the quantitative landslide risk analysis computed as the product of the landslide hazard by the vulnerability and the economic value of the buildings. The hazard was assessed by combining the spatiotemporal probability and the frequency–magnitude relationship of the landslides. The physical vulnerability assessment was based on an inquiry of a pool of European landslide experts and a sub-pool of landslide experts who know the study area, and the answers' variability was assessed with standard deviation. The average vulnerability of the basic geographic entities was compared by changing the map unit and applying the vulnerability to all the buildings of a test site, the inventory of which was listed on the field. The economic value was calculated using an adaptation of the Portuguese Tax Services approach, and the risk was computed for different landslide magnitudes and different spatiotemporal probabilities. As a rule, the vulnerability values given by the sub-pool of experts who know the study area are higher than those given by the European experts, namely for the high-magnitude landslides. The obtained vulnerabilities vary from 0.2 to 1 as a function of the structural building types and the landslide magnitude, and are maximal for 10 and 20 m landslide depths. However, the highest risk was found for the landslides that are 3 m deep, because these landslides combine a relatively high frequency in the Loures municipality with a substantial potential damage.

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Short summary
This paper presents a semi-quantitative assessment of the physical vulnerability of buildings to landslides, and quantitative landslide risk analysis computed as the product of the landslide hazard by the vulnerability and the economic value of the buildings. The work was developed for a Portuguese municipality (Loures). The highest risk was found for the landslides 3 m deep, because these landslides combine a relatively high frequency with a substantial potential damage.
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