third integration dialogue

1. Hydrogeochemistry as a tool for
coastal aquifers management
The case of the Bou Areg aquifer and
the Nador Lagoon (Morocco)
Re Viviana, PhD
Ca' Foscari University of Venice (Italy) & National Engineering School of Sfax (Tunisia)
re@unive.it

2. The Study Area
• Semi-arid climate (300mm/y)
• No regular rain season
• Agricultural activities cover more than 62% of the Bour-Areg plain area

3. Issues
Increase in water
demand
/Overexploitation
Water Scarcity
Saline Water Intrusion
Water Pollution
Food Security
Coastal Aquifer
Arid/ Semi-Arid climate
Population Growth
• Internal migration
• Tourism
Agricultural Activities
Urban and Industrial
development

4. Project Goals
• Overall objectives
– Support science based management practices
– Provide data on water quality in the Bou-Areg coastal aquifer and the
Lagoon of Nador
• Specific objectives
– Assessment of the natural groundwater quality (baseline conditions)
– Evaluation of deviations from the natural conditions
– Assessment of aquifer/lagoon interactions, evaluation of groundwater
quality discharging in the lagoon

5. Methods
– Hydrogeological investigation
– Geochemical analysis of major and trace element
– Isotope geochemistry (δ18O, δ2H, δ18ONO3 ,δ15NNO3, δ13CDIC, δ11B)
– Statistical data treatment
Work performed with contribution of:
Prof.G.M. Zuppi (Scientific Coordinator)
Prof. N. El Hamouti and Mr. R. Bouchnan Faculté pluridisciplinaire de Nador,
Universitè de Oujda (Morocco)
Prof. N. El Amrani, Universitè Hassan I Settat (Morocco)
Prof. E. Sacchi, Università degli studi di Pavia (Italy)
Dr. E. Allais and ISO4 s.n.c. (Italy)
Dr. T. Lovato, Euro Mediterranean Center For Climate Change (Italy)
Prof. J.Mas-Pla and Dr. A Menciò, University of Girona (Spain)
And with the support of the Italian Ministry for the Environment Land and Sea

6. Results
• Sodium-chloride type
• High natural salinity,
mainly due to water-rock
interaction processes
(dissolution of
evaporative rocks and
carbonates)
• Agricultural return flow:
main contribution to
groundwater salinization
especially in the central
part of the aquifer
• [NO3
-] often exceeding
WHO limits
• High dependency on
seasonal variations

7. Results
Oued Selouane
Irrigation
Channel
Agricultural return flow
Water-rock interactions

8. Results
URBAN
RURAL
Identify the main anthropogenic sources
of groundwater pollution
Understand the governing factors of
groundwater vulnerability
UNDERSTANDING THE HYDROGEOLOGYC
SYSTEM & THE ASSOCIATED BEHAVIOR OF
CONTAMINANTS:
A NECESSARY STEP IN GROUNDWATER
VULNERABILITY ASSESSMENT

9. Conclusions
• HIGH AQUIFER SALINITY due to the coexistence of dissolution processes,
water-rock interactions, and human impacts due to agricultural return
flows
Saline water intrusion from the lagoon in the shallow aquifer is negligible,
while discharge of polluted groundwater into the lagoon has been found to
partially alter its quality
• HIGH NITRATE CONCENTRATIONS associated with two main drivers for
human induced pollution:
(i) manure and septic effluents,
(ii) synthetic fertilizers
• HIGH AQUIFER VULNERABILITY
• HIGH DEPENDENCY ON SEASONAL VARIATIONS

10. Management implications
• Need for improving the understanding of groundwater quality
• Control of applied irrigation volumes and identification alternative
irrigation sources to improve groundwater quality
• Enhance public participation and the involvement of local farmer
associations to enforce adequate groundwater protection
Re V., 2011

11. Hydrogeochemistry as a management tool
Water quality
assessment
Pollution
sources
identification
Vulnerability
assessment
Science
based
management
pracrices
• Identification of recharge processes
• Separating baseline conditions from anthropogenic
impacts
• Identification of groundwater and surface water
Interaction
• Identification of mixing processes
• Contaminant-specific vulnerability assessment
• Support the development of effective (science-
based) policies for reducing contaminant loads and
protecting water resources
• Promotion of stakeholder engagement and public
participation
• Development of participatory monitoring assessment

12. Thank you for your attention
Merci pour votre attention
‫النتباهكم‬ ً‫ا‬‫شكر‬
In loving memoriy of Prof. Gian Maria Zuppi