Located in the Aures mountains Foum Toub is characterized by an annual average rainfall of  800mm. The hydrology subordinate to the terrain is the direct consequence of surface waters and of snow melting from the heights of Chelia Mountain. The aim of the implantation of the Foum Toub backwater is to minimize the siltation phenomenon at the upstream of the Koudiate El Mdaour dam, to regularize the Rebaa creek flow which runs from south to north and to contribute to the irrigation of the Foum Toub plain. This study puts the emphasis on the mobilization of surface water resources, a policy of the Ministry of Agriculture and Rural Development with a view to rationalize the use and planning of this vital factor, i.e. water. The site selected for the construction of this structure is characterized by a waterproof marly substratum, favourable for implanting the dike and the basin. The clay-silty-gravelly material furniture localized in the depressions as well as sandstones are used as areas for the construction materials of this structure. Stability is one of the most important parameters to take into account for the choice of the site, so as to avoid any problem linked to the withdrawal-swelling phenomena on the banks of creek. However, the sliding possibility, however weak it is, can be generated on the left bank of the creek within deposit and recent silt. The choice of the site for the implantation of this hydraulic structure remains subject to laboratory tests.

Located in the Aures mountains Foum Toub is characterized by an annual average rainfall of  800mm. The hydrology subordinate to the terrain is the direct consequence of surface waters and of snow melting from the heights of Chelia Mountain. The aim of the implantation of the Foum Toub backwater is to minimize the siltation phenomenon at the upstream of the Koudiate El Mdaour dam, to regularize the Rebaa creek flow which runs from south to north and to contribute to the irrigation of the Foum Toub plain. This study puts the emphasis on the mobilization of surface water resources, a policy of the Ministry of Agriculture and Rural Development with a view to rationalize the use and planning of this vital factor, i.e. water. The site selected for the construction of this structure is characterized by a waterproof marly substratum, favourable for implanting the dike and the basin. The clay-silty-gravelly material furniture localized in the depressions as well as sandstones are used as areas for the construction materials of this structure. Stability is one of the most important parameters to take into account for the choice of the site, so as to avoid any problem linked to the withdrawal-swelling phenomena on the banks of creek. However, the sliding possibility, however weak it is, can be generated on the left bank of the creek within deposit and recent silt. The choice of the site for the implantation of this hydraulic structure remains subject to laboratory tests.

Located in the Aures mountains Foum Toub is characterized by an annual average rainfall of  800mm. The hydrology subordinate to the terrain is the direct consequence of surface waters and of snow melting from the heights of Chelia Mountain. The aim of the implantation of the Foum Toub backwater is to minimize the siltation phenomenon at the upstream of the Koudiate El Mdaour dam, to regularize the Rebaa creek flow which runs from south to north and to contribute to the irrigation of the Foum Toub plain. This study puts the emphasis on the mobilization of surface water resources, a policy of the Ministry of Agriculture and Rural Development with a view to rationalize the use and planning of this vital factor, i.e. water. The site selected for the construction of this structure is characterized by a waterproof marly substratum, favourable for implanting the dike and the basin. The clay-silty-gravelly material furniture localized in the depressions as well as sandstones are used as areas for the construction materials of this structure. Stability is one of the most important parameters to take into account for the choice of the site, so as to avoid any problem linked to the withdrawal-swelling phenomena on the banks of creek. However, the sliding possibility, however weak it is, can be generated on the left bank of the creek within deposit and recent silt. The choice of the site for the implantation of this hydraulic structure remains subject to laboratory tests.

The community of nematodes (Nematoda: Secernentea) in groves of North East Algeria, has been the subject of regular observations of September 2011 to May 2012. Sampling and extraction of nematodes by the buckets technique are conducted following the method of Baermann. The sampling groves are composed by olive trees (Olea europea: Oleaceae) from four varieties: Chemlal, Sigoise, Frontoï and Sévillane. We identified a total of 531 individuals. The systematic inventory revealed 14 genus of Nematoda, belonging to 10 families and 3 orders. The Tylenchida and Dorylaimida are the best represented orders. They represent 92.85% of the total community of all identified nematodes, while Aphelenchida represent only 7.15%. The genus Pratylenchus records alone 54.75% on the Sévillane variety and 33.02% on the Frantoi variety. The most represented genus on Sigoise and Chemlal varieties is Meloidogyne with respectively 43.24% and 30.43%. Grove of Sévillane variety hosts the highest abundance of nematodes with 57.44%; against only 19.96%, 13.94% and 8.66%, respectively, for the varieties Frantoi, Sigoise and Chemlal. Depending on the seasons, nematodes are more abundant in autumn (88.52%) than in winter (8.66%) and the spring (2.82%). Pratylenchus and Meloidogyne are noted with large numbers, especially in winter.

The community of nematodes (Nematoda: Secernentea) in groves of North East Algeria, has been the subject of regular observations of September 2011 to May 2012. Sampling and extraction of nematodes by the buckets technique are conducted following the method of Baermann. The sampling groves are composed by olive trees (Olea europea: Oleaceae) from four varieties: Chemlal, Sigoise, Frontoï and Sévillane. We identified a total of 531 individuals. The systematic inventory revealed 14 genus of Nematoda, belonging to 10 families and 3 orders. The Tylenchida and Dorylaimida are the best represented orders. They represent 92.85% of the total community of all identified nematodes, while Aphelenchida represent only 7.15%. The genus Pratylenchus records alone 54.75% on the Sévillane variety and 33.02% on the Frantoi variety. The most represented genus on Sigoise and Chemlal varieties is Meloidogyne with respectively 43.24% and 30.43%. Grove of Sévillane variety hosts the highest abundance of nematodes with 57.44%; against only 19.96%, 13.94% and 8.66%, respectively, for the varieties Frantoi, Sigoise and Chemlal. Depending on the seasons, nematodes are more abundant in autumn (88.52%) than in winter (8.66%) and the spring (2.82%). Pratylenchus and Meloidogyne are noted with large numbers, especially in winter.