Abstract
In overexploited coastal aquifers threatened or affected by saline intrusion, managed aquifer recharge (MAR) is increasingly applied in the aim of maintaining or recovering freshwater quantity and quality. The long-term regionalscale effectiveness of MAR, however, lacks field examples. The Korba coastal aquifer (Tunisia) has been increasingly overexploited since the 1960s and intensively studied over the last few decades. Groundwater abstraction has resulted in a decline of groundwater levels and a dramatic increase in salinity through both lateral seawater intrusion and shallow salinization from irrigation. MAR strategies, including freshwater injection wells and sewage-water infiltration basins, have been progressively implemented since 1990. Using 50 years of groundwater head and salinity records, a regional three-dimensional numerical groundwater model is calibrated to study the spatiotemporal dynamics of groundwater salinization including the past and future impact of the MAR operations. Results suggest that lateral seawater intrusion
from the coast and shallow infiltration of evapoconcentrated saline irrigation water are the two interlinked dominant regional processes of groundwater salinization, equivalent in magnitude. In accordance with the groundwater
observations, simulated historical MAR operations are shown to have contributed to slowdown and stabilized the regional salinization, which contrasts with the steady rise that is obtained in the hypothetical absence of MAR. The
future MAR simulation scenarios suggest that spatial management of irrigation supplies and injection points from dam freshwater has a potential for further reducing the salinization of shallow groundwater and potentially reversing the
inland progression of the seawater front. Further works should look at reconciling modelling recommendations with management practice options.
from the coast and shallow infiltration of evapoconcentrated saline irrigation water are the two interlinked dominant regional processes of groundwater salinization, equivalent in magnitude. In accordance with the groundwater
observations, simulated historical MAR operations are shown to have contributed to slowdown and stabilized the regional salinization, which contrasts with the steady rise that is obtained in the hypothetical absence of MAR. The
future MAR simulation scenarios suggest that spatial management of irrigation supplies and injection points from dam freshwater has a potential for further reducing the salinization of shallow groundwater and potentially reversing the
inland progression of the seawater front. Further works should look at reconciling modelling recommendations with management practice options.
| Original language | English |
|---|---|
| Pages (from-to) | 91-110 |
| Number of pages | 19 |
| Journal | Journal of Coastal Research |
| Volume | 35 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Jan 2019 |
Bibliographical note
We acknowledge the DGRE of Tunisia and the Regional Commissariat of Agricultural Development of Nabeul (CRDANabeul) for providing access to the technical hydrogeological data of the Eastern Coastal Aquifer of Cap Bon (piezometric and groundwater salinity monitoring, irrigation, groundwater abstraction, and recharge). We also acknowledge the funding from the Tunisian Ministry of Higher Education and Scientific Research for supporting summer placements in Queen's University Belfast and the University of Aberdeen (2014 and 2015). We expand our acknowledgments to three anonymous reviewers for their relevant comments that contributed to improve the final manuscript.Keywords
- irrigated agriculture
- groundwater management
- Irrigated agriculture
- AREA
- BAJA-CALIFORNIA
- SEAWATER INTRUSION
- ARTIFICIAL RECHARGE
- EXAMPLE
- SALINIZATION
- FRESH
- CAP-BON
