Hydrochemical and geoelectrical investigation of Marine Jeffara Aquifer, southeastern Tunisia

Belgacem Agoubi,Tarek Abichou,Habib Abida,Adel Kharroubi

doi:10.1007/s13201-013-0091-4

Belgacem Agoubi, Tarek Abichou + Show 2 more

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https://doi.org/10.1007/s13201-013-0091-4

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Abstract

Hydrogeochemical and geophysical investigation were carried out to assess the geochemical water composition and processes governing groundwater hydrochemistry in Marine Jeffara Aquifer, southeastern Tunisia. A total of 74 groundwater samples were collected and analyzed for various parameters such as pH, electrical conductivity and major ions. Statistical and geochemical modeling were performed to understand the processes controlling groundwater geochemistry. According to their dominance, major ions are classified as follows Cl > Na > SO4 > Ca > Mg > HCO3. Hydrochemical, Na–Ca–Cl–SO4, Ca–Na–Mg–Cl–SO4 and Mg–Ca–Cl–SO4 are the dominant forms in groundwater, mainly as a result of rock–water interaction and saltwater intrusion. Ten vertical electrical resistivity tests were performed in three profiles. The measured low values of electrical resistivity in the coastal areas indicate saltwater mixing with groundwater, as a result of saltwater intrusion.

Highlights

The freshwater crisis is already felt in arid and semi-arid areas like the Marine Jeffara region in southeastern Tunisia on the Mediterranean sea
Rapid increase of salinity is the most widespread form of Marine Jeffara groundwater contamination. This is manifested in an increase of total dissolved solids (TDS) and some specific chemical constituents such as Cl, Na, Ca, Mg, and SO4 (Geminez and Morell 1997; Reddy et al 2010)
High mineralization levels are typically due to recurrent farming and excessive pumping, in turn causing deterioration in groundwater quality and saltwater intrusion (Pazand and Hezarkhani 2012; Bear et al 1999; Mahesha and Nagaraja 1996)

Summary

Introduction

The freshwater crisis is already felt in arid and semi-arid areas like the Marine Jeffara region in southeastern Tunisia on the Mediterranean sea. This region is facing increasing freshwater needs due to a rapidly growing population and increased urbanization. Rapid increase of salinity is the most widespread form of Marine Jeffara groundwater contamination This is manifested in an increase of total dissolved solids (TDS) and some specific chemical constituents such as Cl, Na, Ca, Mg, and SO4 (Geminez and Morell 1997; Reddy et al 2010). Some examples are rock–water interaction, mineral dissolution, agriculture and industrial effluents, mixing water, cation exchange and saltwater intrusion (Appelo and Postma 2005; Reddy et al 2010; Thilagavathi 2012). High mineralization levels are typically due to recurrent farming and excessive pumping, in turn causing deterioration in groundwater quality and saltwater intrusion

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