Combining Social Vulnerability and Physical Vulnerability to Analyse Landslide Risk at the Municipal Scale

Clémence Guillard-Gonçalves,José Zêzere

doi:10.3390/geosciences8080294

Abstract

In this work residents’ social vulnerability and buildings’ physical vulnerability of the Loures municipality (Portugal) were combined to locate the areas where the vulnerability is the highest, and to analyse the landslide risk. The social vulnerability of Loures was assessed using the Geographic Basis for Information Reference (BGRI) terrain units by combining sensitivity and lack of resilience based on the population and housing Census 2011 data. The physical vulnerability was assessed in a previous study based on an inquiry of a pool of European landslide experts and a sub-pool of landslide experts who know the study area. A matrix approach was used to cross the classes of the social and physical vulnerabilities. Finally, the landslide risk was analysed for each terrain unit considering the combined vulnerability, the buildings’ economic value and the landslide susceptibility for a specific landslide magnitude (3-metre-deep rotational slide). Results show that 0.9% of the population reside in the area of the municipality where 75% of the future landslide should occur, and 0.8% of the buildings of the municipality—which represent a value of EUR 146,170,000—are also located in this dangerous area. This approach is reproducible: the risk analysis can be applied for another magnitude scenario in Loures, and the combined vulnerability can be assessed in any Portuguese municipality thanks to the availability of the data.

Highlights

Landslides affect exposed populations worldwide, causing damage, fatalities and injuries.In Portugal, landslides are quite frequent and have been responsible for damage and disruption on roads and buildings
EUR 146,170,000—are located in this dangerous area. This approach is reproducible: the risk analysis can be applied for another magnitude scenario in Loures, and the combined vulnerability can be assessed in any Portuguese municipality thanks to the availability of the data
The present study aims to combine the social vulnerability of residents and the physical vulnerability of buildings in order to analyse landslide risk in a municipality located in the Lisbon region, Portugal

Summary

Introduction

Landslides affect exposed populations worldwide, causing damage, fatalities and injuries.In Portugal, landslides are quite frequent and have been responsible for damage and disruption on roads and buildings. Landslides affect exposed populations worldwide, causing damage, fatalities and injuries. Damage caused by landslides can be reduced with adequate policies and practices. (4) scale-dependent, given that it can be expressed at different scales from human or household to country resolution; and (5) site-specific, which implies that each study area might need its own approach [2]. These dimensions are rarely considered all together in a vulnerability assessment. Most of the scientific studies which assess the vulnerability to natural hazards examine only one facet of the vulnerability of the elements at risk—most of the time, either the social vulnerability or the physical vulnerability

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