The importance of indicator weights for vulnerability indices and implications for decision making in disaster management

Abstract

Decision makers in the field of disaster management have many tools at their disposal to assist them in making informed decisions. They make use of the available information to set priorities, choose adequate local adaptation measures and make decisions regarding land use and emergency planning. As far as the vulnerability assessment of buildings is concerned, a wide range of methods can be found in the literature. However, some methods (e.g. vulnerability curves) require a large amount of empirical data that are not always available. An alternative solution is the development of vulnerability indices. In this paper, two relative vulnerability indices (PTVA-3 and PTVA-4) designed for the assessment of vulnerability of buildings to tsunamis are applied. The case study area is located in Apulia (Italy). Although no historic record of tsunamis is available for the area, geological investigations have shown that the area has been affected by tsunamis in the past. The two methods use different weighting for the indicators considered for the vulnerability index leading to different results. In this way, the importance of the weighting of indicators and its implication in decision making is shown. Moreover, the study offers the opportunity of an overall assessment of the use of indicators in vulnerability assessment, their advantages and drawbacks as well as potential improvements of indicator-based methods.