The working group on Asset Estimation within CEDIM project Risk Map Germany collects and generates information needed for assessing asset values or the exposure of human beings and their respective geographic distribution in Germany. Methodology development plays an important part in the group’s work. It provides CEDIM with data and, by compiling a common glossary of terms, enables interdisciplinary communication between different hazard groups.
To compare risks due to different kinds of hazards (natural as well as man-made) a consistent approach is needed. Risk spans three aspects: hazard, exposed values/persons and their susceptibility (vulnerability). While input data and methods of hazard and vulnerability assessments vary for different perils, a common data base of the potentially exposed values must be used. Compiling peril-spanning information is the challenging task of the Asset Estimation working group (AEG). Besides value assessment, a common use of technical terms shall be ensured by the group.
Main tasks of AEG:
Compiling a glossary of technical terms from different disciplines of risk research
Building up a uniform data base of spatially distributed asset values of different types of buildings and infrastructure elements for the whole area of Germany
The bilingual glossary of terms (German, English) was made public after an external review process (including UNU-EHS, German BBK and DKKV) on the website of CEDIM (http://www.cedim.de/english/864.php). It is recommended for use by the BMBF-funded research programme Risk Management of Extreme Flood Events (RIMAX; link: http://www.rimax-hochwasser.de/) and has been translated to Bulgarian language for Bulgaria by the local Environmental Alliance for Disaster Prevention.
When building up the data base of asset values, private residential buildings of Germany were the first focus of AEG, which lead to several publications presenting both the respective results and its necessary preparatory methodological work (like disaggregating population data to levels even below communities):
1. Relational Approach
- Estimation of the regional stock of residential buildings at the community level (Kleist et al., 2004; Kleist et al., 2006, http://www.copernicus.org/EGU/nhess/6/nhess-6-541.pdf)
- Regionalisation of building values within communities by the means of land use data (Thieken et al., 2006, http://www.copernicus.org/EGU/nhess/6/nhess-6-167.pdf) Zurzeit werden die Vermögenswerte im industriellen, gewerblichen und Dienstleistungssektor mit folgenden Ansätzen ermittelt
Due to the various types of economic activity the business sector is very heterogeneous. Therefore the challenge consists in the development of a method which is able to differentiate the asset values both spatially and concerning business size and type of economic activity. At present, mainly macroeconomic "top-down" approaches for industrial asset estimation are applied (Penning-Rowsell, 2005; Meyer, 2005; Hofstede and Hamann, 2000). These methods need comparably little data (mostly statistical or census data) and enable fast, wide-area assessments. Within the relational approach, the stock of fixed assets (gross and net values) provided by the Federal Statistical Office Germany (Statistisches Bundesamt) is chosen as estimator for the asset values. Assuming a positive correlation between the number of employees and the stock of fixed assets and with the help of geo marketing data, the asset values are allocated for three classes of establishment sizes with 60 branches and 13490 German communities in a first step. In a second step, we aim at a spatial distribution on a smaller scale.
2. Reference Installations Approach
Macro-economic methods are often inaccurate on a more regional level because a homogenous spatial distribution of industrial assets is assumed and the high heterogeneity of industrial sectors and the related installations is not considered. In order to provide a bottom-up method which takes into account this heterogeneity, the reference installation approach has been developed (Merz et al., 2007). However, due to a multitude of individual assets within a sector and the number of sectors taken into account, it is impossible to consider and assess each individual installation in each single sector.
The solution to this problem involves the assignment of individual installations to defined categories of installations, each category being represented by a "reference installation" (see Figure 1). The definition of a reference installation is performed according to the following criteria:
- all installations which can be assigned to a certain reference installation have a similar monetary value;
- all installations which are assigned to one reference installation show similar vulnerability to flood, storm and earthquakes. Thus, the characteristics of the reference installation can be considered as representative values for all installations of the same class.
In the next steps of the project the reference installations are classified according to the above described criteria. The monetary value of the reference installations is determined by means of site surveys, interviews with branch experts and representatives of industrial associations and literature data. After the classification of reference installations all industrial installations of a test region are assigned to the reference installations and the values of industrial assets of the test region are estimated.
Following, these results will be compared with the industrial assets estimated by the relation approach for the test region.
BMBF-Forschungsprogramm Risikomanagement extremer Hochwasserereignisse (RIMAX)