Examples of geomorphologic and geological hazards in Algeria

Abstract

International audienceWe present three geomorphologic and geological phenomena that have occurred in Algeria in recent years: (i) the Bab El Oued mudflow on 11 November 2001, which claimed several hundred lives, (ii) a soil collapse induced by sand liquefaction triggered by the Boumerdes earthquake (M w = 6.8) on 21 May 2003, and (iii) landslides that are threatening Constantine city, for which a hazard map is presented using a qualitative approach. We briefly describe and analyze these natural disasters, and in the first two cases propose the application of geophysical techniques such as ambient noise recordings and electrical imagery to help evaluate their extent and potential threat. Finally a landslide hazard map of Constantine is proposed

Evidence for an underground runoff and soil permeability at the Ouled Fayet (Algiers, Algeria) subsurface landfill pilot project from geophysical investigations

“…Such a reoccupation of a dry bed by water following heavy rain occurred with dramatic consequences in Algiers in 2001 (e.g. Machane et al 2008). Not only the construction of a landfill at Ouled Fayet is questionable, but also cell #3 should definitively not have been constructed, and no cell should be crossed by or located next to the wadi tributary (see relative locations of the tributary bed and cell #4 on Fig.…”

Failure of landslide stabilization measures: The Sidi Rached viaduct case (Constantine, Algeria)

“…In the last few decades, several districts of the city have been threatened by landslides (e.g. Machane et al, 2008). About 120 hectares, 15,000 buildings and 100,000 people are concerned (Benazzouz, 2002).…”

“…This study investigates the Sidi Rached viaduct landslide, and is based on our field investigations and the reappraisal of available inclinometric data from two drillings, as well as previous studies including (1) scientific publications (Benaissa et al, 1989;Benaissa and Bellouche, 1999;Benazzouz, 2002;Machane et al, 2008;Pincent et al, 2008), (2) theses and dissertations (Bencheniouni and Chorfi, 2003;Machane, 2003;Guemache, 2004;Bougdal, 2007), (3) expert reports (LNTPB, 1980;LTPE, 1999;Genevois, 2000), and (4) archives from the ''Direction de l'Urbanisme de la Wilaya de Constantine''.…”

The Laalam (Algeria) damaging landslide triggered by a moderate earthquake (Mw = 5.2)

“…Therefore, it is important to consider these phenomena in any strategy of development and land planning in mountainous areas of seismically active regions. In Algeria, moderate to strong earthquakes are often associated with secondary hazards, particularly landslides (Gabert 1984;Benouar 1994;Bouhadad et al 2003Bouhadad et al , 2004Machane et al 2008). During the Chenoua earthquake of October 1989 (M s = 5.7), rock falls obtruded roads and, hence, delaying the rescue operations.…”