What is the context of the assessment?
Assessments differ according to the scales on which they measure risk or vulnerability. Units and scales are of importance at two points in an assessment:
- Data collection: the decision about measurement units and scales is influenced by the data on which the assessment is based. Units and scales might be predefined you use official statistics or the measure values are ascribed to certain objects. In case you are planning to gather data by your own you need to decide which is the appropriate level or unit of analysis to answer your research question. This decision might also be related to the definition of vulnerability which is applied.
- Data analysis: The unit of reference for the analysis and presentation of results might differ from the level on which data was gathered originally. This often occurs if data is aggregated across spatial or adminstrative units or if comprehensive and complex indixes are computed. Some assessments also cover more than one scale or aggregate information on a higher level.
Please note that we distinguish between the spatial and temporal scales of drivers and the assessments itself. Whereas the scales in the assessments mainly result from a decisions of the researcher or the structure of the data the spatial and temporal scale of vulnerability drivers are determined by the type of the hazard.
Ontology branch about the reference framework of the assessment
In our ontology we introduce four attributes that should help to describe temporal, spatial and social scales on which data is gathered or analysed. These attributes are described in the following sections:
The Social Scale
The social scale refers to the smallest social entities which are addressed by the assessment. This might be individuals, households, neighbourhoods or communities. In disctinction from the spatial scale social relationships between the elements are in the foreground and the main criteria for sampling. Of course social relationships coincide with spatial proximity.
The Spatial Scale
The spatial scale encompasses three dimensions: first it describes in abstract terms the level of aggregation. This could either be a grid or spatial units like wards and districts on subcity levels, entire cities, villages, counties or even countries. Second the geographical area where the assessment was conducted or to which the results refer is specified. The research area in an assessment might overlap with the region at region, but they are not necessarily congruent (example?). Additionally the research areas are grouped according to their economic status. The classification of the geographical area as well as the economic grouping are based on the lists of the United Nations Statistics Division.
The Temporal Scale
Vulnerability assessments either refer to a point in time or to a specific period. In our ontology we distinguish between:
- short term (several months to one year),
- mid term (1 to 5 years),
- and long term assessments (more than 5 years).
We explicitely refrain from defining concrete numbers of months or years because the time span which is considered in the assessment strongly depends on the hazard which triggers vulnerability, the research question or even the theoretical background of the assessments. For example Watts and Bohle discuss a dynamic concept of vulnerability. They distinguish between the baseline vulnerability which is determined by basic societal structures (e.g. access to power or ressources) and the current vulnerability which results from an interaction between triggering events and the societal structures. Thus Watts and Bohle's conceptualization is in line with the Pressure and Release Approach. Consequentely studies in the tradition of these models are likely to consider longer time intervals.
- ↑ Watts, MJ & Bohle, HG 1993, 'The space of vulnerability: the causal structure of hunger and famine', Progress in Human Geography, vol. 17, no. 1, pp. 43–67.