Groundwater for Sustainable Development 11 (2020) 100481
Available online 12 September 2020
2352-801X/© 2020 Elsevier B.V. All rights reserved.
Research paper
Mapping of the vulnerability to marine intrusion “in coastal Cherchell
aquifer, Central Algeria” using the GALDIT method
Nadia Amarni
a,*
, Lounes Fernane
a
, Mohammed Naili
b
, Ryhane Lounas
a
, Rabah Belkessa
a
a Laboratoire des ´
Ecosyst` emes Marins et Littoraux (ECOSYSMarL), Ecole Nationale Sup´ erieur des Sciences de la Mer et de l’Am´ enagement du Littoral (E.N.S.S.M.A.L),
Campus Universitaire de Dely Ibrahim Bois des Cars, Dely Ibrahim, 16320, Alger, Algeria
b SNC-LAVALIN, 275 rue Benjamin Hudon, Saint-Larent, Qu´ ebec, Canada
A R T I C L E I N F O
Keywords:
Cherchell coastal aquifer
Vulnerability mapping
Marine intrusion
GALDIT method
GIS
Algeria
A B S T R A C T
Located in the south of the western Mediterranean, in the central Algerian region, the Cherchell coastal aquifer
has participated over time in the economic development of the region (agriculture and seaside tourism). The
construction of the Boukerdene dam in the watershed of the region, thus the exploitation of the aquifer in
response to the excessive demand of agriculture and the potable water supply, has caused the piezometric level of
the aquifer to decline and threatens its sustainability and makes it more vulnerable to marine intrusion, noting
that no work has been realized in this study area despite the inestimable value of this aquifer in the region, it’s
the only aquifer in Cherchell town. The aim of this paper is to map the vulnerability of this aquifer to marine
intrusion, based on the proven methodology of the GALDIT model for coastal aquifers combined with Geographic
Information Systems (GIS). The GALDIT methodology requires six input parameters: groundwater occurrence
(G), aquifer hydraulic conductivity (A), groundwater head above sea level (L), distance from the shore (D),
impact of the existing status of seawater intrusion l’impact (I), and thickness of the aquifer (T).
The results indicate low to moderate vulnerability upstream and high vulnerability downstream. This high
vulnerability can be as much as 700 m from shoreline inland. This vulnerability is mainly due to the hydrological
disruption linked to the construction of the Boukerdene dam, which reduces surface water inflows. These results
provide a basic tool for local managers and decision-makers, for future management and protection strategies for
the Cherchell area aquifer in the face of marine intrusion.
1. Introduction
Coastal zones are socio-economic components of significant importance for the present and the future. Human interactions affect these
fragile environments and threaten their sustainability, such as freshwater aquifers. Coastal aquifers are major sources of freshwater provision, especially in low precipitation areas. Groundwater reserves are
mostly very stable because the groundwater flow time is very slow
(Niazi, 2007). However, this precious resource is threatened by excessive exploitation and decreasing piezometric levels, hence the possibility
of being contaminated by the intrusion of marine water intrusion (Niazi,
2007). In addition to climate change impacts, like low precipitation and
expected sea level rise, the salinity of coastal aquifers could increase
(Medejerab and Henia, 2011; Szczypta, 2012). This hazard has been the
subject of several studies around the world; India (Chachadi et al.,
2003), Portugal (Lobo-Ferreira et al., 2003), USA (Tasnim and Tahsin,
2016; Moghaddam et al., 2019), Morocco (Niazi, 2007; Batchi, Karkouri
et al. 2014, 2017), Tunisia (Saidi et al., 2011). Algeria is not exempt
from this risk and many studies have been carried out in recent years to
assess the vulnerability of coastal aquifers to marine intrusion, citing
Guerbes-Annaba (Guezgouz n and Bouhsina), El Nador-Tipaza (Bouderbala et al., 2016), Mitidja (Djoudar et al., 2017), Bouteldja-El Taref
(Hallal et al., 2019), Souk el Thenine-Bejaya (Boudjelil and Djafari,
2018), Collo-Skikda (Mahrez et al., 2018; Djabri et al., 2019). Algeria
has considerable groundwater freshwater reserves. Its reserves are
estimated at about 8.5 billion m
3
, of which 2.5 billion in the northern
regions and 6 billion in the Sahara, these resources are considered
non-renewable (Mahrez et al., 2018). The increasing use of these waters
exposes them to greater vulnerability to overexploitation and contamination (Baghvand et al., 2010), particularly in the coastal zone, which is
* Corresponding author.
E-mail addresses: amarninadia@hotmail.com (N. Amarni), lounes15@live.fr (L. Fernane), naili40mohammed@hotmail.com (M. Naili), louna.ryhane@gmail.com
(R. Lounas), belkessarabah@yahoo.fr (R. Belkessa).
Contents lists available at ScienceDirect
Groundwater for Sustainable Development
journal homepage: http://www.elsevier.com/locate/gsd
https://doi.org/10.1016/j.gsd.2020.100481
Received 26 September 2019; Received in revised form 21 July 2020; Accepted 4 September 2020
Available online 12 September 2020
2352-801X/© 2020 Elsevier B.V. All rights reserved.
Research paper
Mapping of the vulnerability to marine intrusion “in coastal Cherchell
aquifer, Central Algeria” using the GALDIT method
Nadia Amarni
a,*
, Lounes Fernane
a
, Mohammed Naili
b
, Ryhane Lounas
a
, Rabah Belkessa
a
a Laboratoire des ´
Ecosyst` emes Marins et Littoraux (ECOSYSMarL), Ecole Nationale Sup´ erieur des Sciences de la Mer et de l’Am´ enagement du Littoral (E.N.S.S.M.A.L),
Campus Universitaire de Dely Ibrahim Bois des Cars, Dely Ibrahim, 16320, Alger, Algeria
b SNC-LAVALIN, 275 rue Benjamin Hudon, Saint-Larent, Qu´ ebec, Canada
A R T I C L E I N F O
Keywords:
Cherchell coastal aquifer
Vulnerability mapping
Marine intrusion
GALDIT method
GIS
Algeria
A B S T R A C T
Located in the south of the western Mediterranean, in the central Algerian region, the Cherchell coastal aquifer
has participated over time in the economic development of the region (agriculture and seaside tourism). The
construction of the Boukerdene dam in the watershed of the region, thus the exploitation of the aquifer in
response to the excessive demand of agriculture and the potable water supply, has caused the piezometric level of
the aquifer to decline and threatens its sustainability and makes it more vulnerable to marine intrusion, noting
that no work has been realized in this study area despite the inestimable value of this aquifer in the region, it’s
the only aquifer in Cherchell town. The aim of this paper is to map the vulnerability of this aquifer to marine
intrusion, based on the proven methodology of the GALDIT model for coastal aquifers combined with Geographic
Information Systems (GIS). The GALDIT methodology requires six input parameters: groundwater occurrence
(G), aquifer hydraulic conductivity (A), groundwater head above sea level (L), distance from the shore (D),
impact of the existing status of seawater intrusion l’impact (I), and thickness of the aquifer (T).
The results indicate low to moderate vulnerability upstream and high vulnerability downstream. This high
vulnerability can be as much as 700 m from shoreline inland. This vulnerability is mainly due to the hydrological
disruption linked to the construction of the Boukerdene dam, which reduces surface water inflows. These results
provide a basic tool for local managers and decision-makers, for future management and protection strategies for
the Cherchell area aquifer in the face of marine intrusion.
1. Introduction
Coastal zones are socio-economic components of significant importance for the present and the future. Human interactions affect these
fragile environments and threaten their sustainability, such as freshwater aquifers. Coastal aquifers are major sources of freshwater provision, especially in low precipitation areas. Groundwater reserves are
mostly very stable because the groundwater flow time is very slow
(Niazi, 2007). However, this precious resource is threatened by excessive exploitation and decreasing piezometric levels, hence the possibility
of being contaminated by the intrusion of marine water intrusion (Niazi,
2007). In addition to climate change impacts, like low precipitation and
expected sea level rise, the salinity of coastal aquifers could increase
(Medejerab and Henia, 2011; Szczypta, 2012). This hazard has been the
subject of several studies around the world; India (Chachadi et al.,
2003), Portugal (Lobo-Ferreira et al., 2003), USA (Tasnim and Tahsin,
2016; Moghaddam et al., 2019), Morocco (Niazi, 2007; Batchi, Karkouri
et al. 2014, 2017), Tunisia (Saidi et al., 2011). Algeria is not exempt
from this risk and many studies have been carried out in recent years to
assess the vulnerability of coastal aquifers to marine intrusion, citing
Guerbes-Annaba (Guezgouz n and Bouhsina), El Nador-Tipaza (Bouderbala et al., 2016), Mitidja (Djoudar et al., 2017), Bouteldja-El Taref
(Hallal et al., 2019), Souk el Thenine-Bejaya (Boudjelil and Djafari,
2018), Collo-Skikda (Mahrez et al., 2018; Djabri et al., 2019). Algeria
has considerable groundwater freshwater reserves. Its reserves are
estimated at about 8.5 billion m
3
, of which 2.5 billion in the northern
regions and 6 billion in the Sahara, these resources are considered
non-renewable (Mahrez et al., 2018). The increasing use of these waters
exposes them to greater vulnerability to overexploitation and contamination (Baghvand et al., 2010), particularly in the coastal zone, which is
* Corresponding author.
E-mail addresses: amarninadia@hotmail.com (N. Amarni), lounes15@live.fr (L. Fernane), naili40mohammed@hotmail.com (M. Naili), louna.ryhane@gmail.com
(R. Lounas), belkessarabah@yahoo.fr (R. Belkessa).
Contents lists available at ScienceDirect
Groundwater for Sustainable Development
journal homepage: http://www.elsevier.com/locate/gsd
https://doi.org/10.1016/j.gsd.2020.100481
Received 26 September 2019; Received in revised form 21 July 2020; Accepted 4 September 2020