Origin of water salinity in Annaba aquifer system, North-Eastern Algeria | JBES-Vol-11-No-6

J. Bio. & Env. Sci. 2017
Introduction
In this latter case, the two systems do not mix,
The aquifers exploitation in coastal zones is generally
because saltwater move below freshwater owing to
a crucial issue since it combines the notion of quantity
the density difference between the two types of water
with quality (Ledoux, 1986). Coastal regions are often
(Custodio and Llamas, 1983; Pulido-Bosch et al.,
areas where there is generally a large demand for
1996; Martos and Pulido-Bosch, 1996; Hai Van and
water due to the multiple activities of large
Sang-Il, 2015; Dilip Kumar and Bithin, 2017.
agglomerations such as agriculture, industry and
tourism. These overpopulated coastal areas with very
Many authors (Bear et al., 2001, Calvache and Pulido-
intense economic activities, require quantity and
Bosh, 1991, Rivera et al., 1990) have attempted,
uncontaminated water resources.
through analytical and numerical modeling methods,
to describe the phenomenon, to predict the position
This coastal aquifer in contact with the sea is naturally
of the interface between freshwater and seawater and
in equilibrium, the groundwater coming from the
predict the change of piezometric head and salinity.
infiltration of pluviometric water constitutes a
groundwater moving towards the sea which surmounts
Characterization of the intrusion phenomenon requires
a saltwater body in a wedge penetrating inside lands.
an interdisciplinary approach which consists in
Any over-pumping of freshwater from a wellfield will
establishing the geological structure, determining the
alter this equilibrium state by reducing the flow of
hydrological and hydrochemical properties by a
groundwater and lowering the groundwater. This
sufficient number of measurements and analyzes in
results in the extension of an inland salt wedge that can
order to characterize the origins of the salinity, the
reach in some places, the bottom of the wells and even
lead to a change in the direction of the runoff (Bonnet
et al., 1974; Gourgand et al., 1988).
location of the interface and the functions that cause
spatio-temporal evolution (Banton and Bangoy, 1999).
The captive aquifer studied in this article is located in the
Seybouse basin in northeastern Algeria (Fig. 1 and 2).
For example, the coastal areas (northern part) of the
study area, where there is over pumping for domestic
and industrial consumption, are areas where
groundwater is vulnerable to salt contamination and
where aquifers are in direct contact with the
ALGERIA
EDOUGH
Mediterranean Sea
ANNABA
Mafragh River
g
Mediterranean. The purpose of these studies is to
investigate the mechanisms of seawater intrusion, to
characterize saline pollution and to highlight the
governing factors and the tools of controlling the
contamination of water tables by seawater.
Fetzara
Lake
Ressoul
Meboudja
El Hadjar
Ben
Ahmed
Seybouse River
Graben
Daroussa
Salines
Elevation
of
Ben M'hidi
Besbes
Daroussa
Zerizer
Graben
Mekrada
Ben
M'hidi
Lake
Kebir
Sebaa
River
Bouteldja
h
Drean
Freeze and Cherry (1979) define seawater intrusion as
the migration of saltwater into aquifer freshwater,
under the influence of the evolution of groundwater
resources. The movement occurs naturally, either
inland; this is a downward movement from the
5 km.
Chihani
Asfour
Cheffia & El-Kala
Mounts
1 2 3 4 5
6 7 8 9
surface sources and irrigation water to the aquifer
Fig. 1. Geological map of the Annaba plain
and an upward movement of the lower formations
Legend: (1) recent alluvia; (2) dunes; (3) ancient alluvia;
into the aquifer, or in coastal areas where aquifer
(4) lakes or ponds; (5) Numidian sandstones or clays; (6)
waters are hydraulically linked to seawater (El
metamorphic formations (micaschists, gneisses,
Achheb et al., 2001; Pulido-Bosch et al., 1998).
marbles); (7) fault; (8) graben; (9) cross plot.
261 | Hamzaoui et al.