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Papers by abdelmalek goumih

Research paper thumbnail of Evolution of chemical and isotopic composition of inorganic carbon in a complex semi-arid zone environment: Consequences for groundwater dating using radiocarbon

Geochimica et Cosmochimica Acta, 2016

Estimating groundwater age is important for any groundwater resource assessment and radiocarbon (... more Estimating groundwater age is important for any groundwater resource assessment and radiocarbon (14 C) dating of dissolved inorganic carbon (DIC) can provide this information. In semi-arid zone (i.e. water-limited environments), there are a multitude of reasons why 14 C dating of groundwater and traditional correction models may not be directly transferable. Some include; (1) the complex hydrological responses of these systems that lead to a mixture of different ages in the aquifer(s), (2) the varied sources, origins and ages of organic matter in the unsaturated zone and (3) high evaporation rates. These all influence the evolution of DIC and are not easily accounted for in traditional correction models. In this study, we determined carbon isotope data for; DIC in water, carbonate minerals in the sediments, sediment organic matter, soil gas CO 2 from the unsaturated zone, and vegetation samples. The samples were collected after an extended drought, and again after a flood event, to capture the evolution of DIC after varying hydrological regimes. A graphical method (Han et al., 2012) was applied for interpretation of the carbon geochemical and isotopic data. Simple forward mass-balance modelling was carried out on key geochemical processes involving carbon and agreed well with observed data. High values of DIC and d 13 C DIC , and low 14 C DIC could not be explained by a simple carbonate mineral-CO 2 gas dissolution process. Instead it is suggested that during extended drought, water-sediment interaction leads to ion exchange processes within the top $10-20 m of the aquifer which promotes greater calcite dissolution in saline groundwater. This process was found to contribute more than half of the DIC, which is from a mostly 'dead' carbon source. DIC is also influenced by carbon exchange between DIC in water and carbonate minerals found in the top 2 m of the unsaturated zone. This process occurs because of repeated dissolution/precipitation of carbonate that is dependent on the water salinity driven by drought and periodic flooding conditions. This study shows that although 14 C cannot be directly applied as a dating tool in some circumstances, carbon geochemical/isotopic data can be useful in hydrological investigations related to identifying groundwater sources, mixing relations, recharge processes, geochemical evolution, and interaction with surface water.

Research paper thumbnail of Climate Change Impact on Aquifer System of Essaouira Basin during the Past 4 Decades (Morocco)

Open Journal of Modern Hydrology, 2016

Research paper thumbnail of Isotopic Tool and Problematic of Recharge in Semi-Arid Area: The Case of the Coast Zone of Essaouira Basin (Morocco)

Journal of environment and earth science, 2016

The Essaouira coastal zone is one of the Moroccan semi-arid areas with annual rainfall not exceed... more The Essaouira coastal zone is one of the Moroccan semi-arid areas with annual rainfall not exceeding 300 mm/year. This area contains several main aquifers such as: The Plio-quaternary aquifer consisting of sandstones, the Turonian aquifer composed of chalk-dolomitic rocks, the Barremian-Aptian aquifer content in calcareous clay formations, fossil limestone and sandstone and the Hauterivian aquifer housed formations of marl clay alternating with hard siliceous limestone and calcareous marl. The study had framework on the most important aquifers of the Eassouira coast zone, while having as principal objectives the dating of underground waters of the region and the sampling of main water points that supply drinkable water to the city as well as to the rural agglomerations. Different water samples were collected from drillings, sources and wells belonging to the Plio-quaternary, Turonian, Barremian-Aptian and Hauterivian aquifers of the studied region. Their electric conductivity, pH an...

Research paper thumbnail of Assessment the climate change impact on the future evapotranspiration and flows from a semi-arid environment

Arabian Journal of Geosciences

Research paper thumbnail of Evolution of chemical and isotopic composition of inorganic carbon in a complex semi-arid zone environment: Consequences for groundwater dating using radiocarbon

Geochimica et Cosmochimica Acta, 2016

Estimating groundwater age is important for any groundwater resource assessment and radiocarbon (... more Estimating groundwater age is important for any groundwater resource assessment and radiocarbon (14 C) dating of dissolved inorganic carbon (DIC) can provide this information. In semi-arid zone (i.e. water-limited environments), there are a multitude of reasons why 14 C dating of groundwater and traditional correction models may not be directly transferable. Some include; (1) the complex hydrological responses of these systems that lead to a mixture of different ages in the aquifer(s), (2) the varied sources, origins and ages of organic matter in the unsaturated zone and (3) high evaporation rates. These all influence the evolution of DIC and are not easily accounted for in traditional correction models. In this study, we determined carbon isotope data for; DIC in water, carbonate minerals in the sediments, sediment organic matter, soil gas CO 2 from the unsaturated zone, and vegetation samples. The samples were collected after an extended drought, and again after a flood event, to capture the evolution of DIC after varying hydrological regimes. A graphical method (Han et al., 2012) was applied for interpretation of the carbon geochemical and isotopic data. Simple forward mass-balance modelling was carried out on key geochemical processes involving carbon and agreed well with observed data. High values of DIC and d 13 C DIC , and low 14 C DIC could not be explained by a simple carbonate mineral-CO 2 gas dissolution process. Instead it is suggested that during extended drought, water-sediment interaction leads to ion exchange processes within the top $10-20 m of the aquifer which promotes greater calcite dissolution in saline groundwater. This process was found to contribute more than half of the DIC, which is from a mostly 'dead' carbon source. DIC is also influenced by carbon exchange between DIC in water and carbonate minerals found in the top 2 m of the unsaturated zone. This process occurs because of repeated dissolution/precipitation of carbonate that is dependent on the water salinity driven by drought and periodic flooding conditions. This study shows that although 14 C cannot be directly applied as a dating tool in some circumstances, carbon geochemical/isotopic data can be useful in hydrological investigations related to identifying groundwater sources, mixing relations, recharge processes, geochemical evolution, and interaction with surface water.

Research paper thumbnail of Climate Change Impact on Aquifer System of Essaouira Basin during the Past 4 Decades (Morocco)

Open Journal of Modern Hydrology, 2016

Research paper thumbnail of Isotopic Tool and Problematic of Recharge in Semi-Arid Area: The Case of the Coast Zone of Essaouira Basin (Morocco)

Journal of environment and earth science, 2016

The Essaouira coastal zone is one of the Moroccan semi-arid areas with annual rainfall not exceed... more The Essaouira coastal zone is one of the Moroccan semi-arid areas with annual rainfall not exceeding 300 mm/year. This area contains several main aquifers such as: The Plio-quaternary aquifer consisting of sandstones, the Turonian aquifer composed of chalk-dolomitic rocks, the Barremian-Aptian aquifer content in calcareous clay formations, fossil limestone and sandstone and the Hauterivian aquifer housed formations of marl clay alternating with hard siliceous limestone and calcareous marl. The study had framework on the most important aquifers of the Eassouira coast zone, while having as principal objectives the dating of underground waters of the region and the sampling of main water points that supply drinkable water to the city as well as to the rural agglomerations. Different water samples were collected from drillings, sources and wells belonging to the Plio-quaternary, Turonian, Barremian-Aptian and Hauterivian aquifers of the studied region. Their electric conductivity, pH an...

Research paper thumbnail of Assessment the climate change impact on the future evapotranspiration and flows from a semi-arid environment

Arabian Journal of Geosciences