DISTRIBUTION ET FLUX DU SILISIUM DANS LE BASSIN VERSANT DE SEYBOUSE (Nord-Est Algérien)
No Thumbnail Available
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Université Abbes Laghrour -Khenchela-
Abstract
Abstract
Silicon is the most abundant element in the earth's crust after oxygen, and is found in aquatic
environments in the form of orthosilicic acid. For the first time, this study concerned the
distribution and flow of silicon at strategic sites (Foum elkhanga dam, Bouhamdane dam and
estuary) of the Seybouse basin during the period between September 2016 (Dry season) and
April 2017 ( Wet season). It is a question of following the evolution of this element from the
upstream of the catchment to the mouth in order to understand these biogeochemical
transformations under the effect of the dams and the estuary. Seybouse watershed waters are
considered to be characterized by medium high silicon concentrations, particularly upstream of
dams, but their contents are reduced downstream of dams and particularly at the mouth. The
highest grades are observed upstream of the dams and weakened by going downstream from the
dams, the estuary and the mouth. Dissolved silicon is reduced between 47
μM (32%) and 72 μM
(54%) for the elkhanga and Bouhamdane foum dam, respectively, while the estuary retention
rate is on average 34
μM (44%). It is noted that the silicates have been subjected to a high
retention in the dams and also in the estuary to ultimately reach minimum values of the order of
42
μ
M at the mouth. The Foum elkhanga and Bouhamdane dam produces an average of 2 t / yr
(7%) and 17 (68%) respectively, while the estuary produces 54 t / yr ( 11%); The dams and the
estuary can be considered to function as true Si producers in the coastal zone. From a
biogeochemical point of view, they should play a crucial role in changes in the biogeochemical
cycles of nutrients. These hydrological and biogeochemical conditions are expected to have
severe impacts on the river system and the functioning and production of the receiving coastal
renewable resources.