How is vulnerability measured?
The measurement of vulnerability is on the one hand described by the methods which are applied to gather and analyse data and on the other hand by the theoretical approach respectively framework on which the study or measurement conception is based. In the wiki the methodological approach is represented twice: You can find rough information about the data collection and analysis methods on the wikipage for an concrete assessment and more details on the pages which deal with a specific assessment method. First of all the operational approach is characterized by a certain research design: we distinguish between longitudinal, cross-sectional, case studies and assessments which have a strong focus on defining indicators that measure vulnerability. Since indicators are a key element in an assessment and have a strong impact on its validity we are especially interested in giving at least an overview about the applied indicators. Sometimes the choice of indicators is restricted to secondary data which is for example provided by official statistics whereas in other contexts researchers develop ad hoc indicators.
The mindmap gives an overview about all captured aspects of the operational approach of vulnerability assessments.
Methods of data collection
Various methods and sources can be used to gather information about the vulnerability of a certain place or system:
- (Face to face) interviews
- Surveys (based on questionnaires)
- Expert interviews
- Group discussion / focus groups
- Auxiliary data / official statistics
- GIS data
- Content analysis of artifacts (documents, images etc.)
Dependent on its source data can be considered as secondary data, if it is collected by someone else than the investigator or primary data, if it is gathered specifically for this purpose by the investigators themselves. Methods of inquiry that rather focus on in depth understanding of human behavior and its reasons are labeled as qualitative. Often these methods use non-standardized instruments and rather ask "why" or "how" something happened instead of "where", "when" or "what". In some cases concerned people or stakeholders participate in steps of the research process and the relationship between experts and the community is less or even non-hierarchical.
Methods of data analysis
In vulnerability studies various methods are used to analyse data:
- multivatiate statistics (e.g. regression analysis, factor analysis or PCA)
- content analysis
- historical or policy analysis
- uncertainty treatment
- modelling and simulation
- spatial analysis
- spatial or temporal mapping
Conceptualizations of vulnerability vary across research domains and impinge on the choice and design of research instruments. Hence a discussion of an assessment should always take into account the theoretical framework. Each conceptual framework can comprise a multitude of factors which determine vulnerability but unfortunately these frameworks are incompatible to each other and no overall framework is existing. Hanns-Martin Füssel argues that termninological confusion mainly results from a unclear distinction between the dimensions sphere and knowledge domain and proposes a minimal structure to classify the multitude of apporaches. Whereas the "sphere" respectively "scale" describes whether a vulnerability factor is considered as internal or external to the system, the second dimension "knowlegde domain" distinguishes between socio-economic and biophysical factors, which can of course overlap. Socioeconomic factors encompass aspects like access to power and resources, social networks as well as policies, international aid or economic globalization. In comparison biophysical aspects of vulnerability refer to topography, environmental conditions, land cover or hazards like earthquakes, strom or sea-level-rise.
The mindmap gives an overview about all captured aspects of the theoretical approach of vulnerability assessments.
Based on Hanns-Martin Füssel ideas (Füssel 2006)  we classify the assessments according to their main conceptual lineage:
- Risk-Hazard approach
- Political economy approach
- Pressure and release model
- Integrated approaches
- Resilience approach
The table below illustrates which kind of vulnerability factors these approaches take in to account.
|Risk-hazard||-||X||-||-||Internal biophysical vulnerability|
|Political economy||X||-||?||-||Cross-scale socioeconomic vulnerability|
|Pressure and release||X||X||-||-||Internal integrated vulnerability|
|Integrated||X||X||X||X||Cross-scale integrated vulnerability|
|Resilience||X||X||?||?||Cross-scale (?) integrated vulnerability|
IS= internal socioeconomic
IB= internal biophysical
ES= external socioeconomic
EB= external biophysical
Source: Füssel (2006)
- Vulnerability of what?
- Vulnerability to what?
- What is the context of the assessment?
- ↑ Füssel, H. -M (2007): Vulnerability: A generally applicable framework for climate change research. In: Global Environmental Change, V. 17, p. 155–167.