Improvement of the consideration of seismic risks in Algerian planning and urban development instruments: Application to the Boumerdés region (50km east of Algiers/Algeria)

Abstract

The territory of both Algiers and Boumerdés departments was hit in 2003 by a violent earthquake of 6.8 (M) causing considerable human and material losses. In order to establish preventive solutions, the article recommend the seismic risk studies to be considered in national and urban planning instruments, It presents a seismic vulnerability study applied to three (03) cities located in the region that have high populations and challenges Two assessments are presented for each city: the first consists of studying the vulnerability of buildings to the earthquake using a qualitative empirical method called Risk-EU. The second assessment focuses on the unbuilt part of the city through the analysis of evacuation and rescue capacity after the earthquake. This latter is a method used in the seismic micro zoning study of the wilaya of Algiers that was jointly established by 02 Japanese and Algerian study centers. The superposition of the summary vulnerability maps of the two assessments designed using a geographic information system (GIS), shows us the location of the most vulnerable urban areas. Damage of the building is coupled with their degree of isolation that serves for evacuation and rescue in the case of an earthquake. The results of cumulative vulnerability (built and urban system) at the scale of the region studied, then at each city and districts, are shown graphically and statistically.