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Dwelling fractions

Analysing the information available in the various census surveys, the most important common features for classifying the building stock according to the expected seismic response were selected: i) predominant material of the exterior walls, ii) material of the floor, iii) type of dwelling, and iv) type of area (urban or rural). None of the surveys included information about the number of storeys, nor the lateral load resisting system, and only the census from Venezuela made reference to the year of construction.

The reason why four attributes were selected is due to the capability of downloading disaggregated data from the different web-based applications. For Colombia and Venezuela the type of dwelling was not included because disaggregation of data was only available for a maximum of three attributes. Note that the first version of the regional mapping scheme for South America presented in the previous progress report only considered two attributes for building classification: the typical material used on the exterior walls and floor.

In brief, for each country two mapping schemes were produced: one for urban areas and one for rural areas. Each mapping scheme consists of two tables: the first table assigns an initial building group according to the material of the exterior walls and the material of the floor; then the second table assigns the dwelling fractions according to the initial building group and the type of dwelling (Colombia and Venezuela do not have the second table). Finally, by multiplying the number of dwellings times the dwelling fractions, the number of dwellings per building typology is calculated at each geographical scale. The building typologies have been defined in accordance with the GEM Building Taxonomy v2.0.

A new mapping scheme has been established for each country taking into account the information available in the Global Exposure Database (GED, that includes PAGER and UN-HABITAT building fractions), the housing reports from the World Housing Encyclopedia (WHE), the results coming from the exposure session of the GEM workshop at Medellin and national and sub-national datasets (census information).

...see more about mapping scheme methodology

  • risk/exposure/dwelling_fractions.1441960413.txt.gz
  • Last modified: 2015/09/11 10:33
  • by Catalina Yepes