Hydrochemical and isotopic assessment for characterizing groundwater quality and recharge processes under a semi arid area: Case of the Haouz plain aquifer (Central Morocco)

The exploitation of groundwater in arid and semi-arid areas, especially in basins where groundwater is intensively exploited, is likely to have adverse effects on the originally fragile ecological environment, which also greatly alter the hydrogeochemical evolution process. Over-abstraction of groundwater in the Haolebaoji watershed of the Ordos Basin located in the semi-arid regions has led to a series of changes in the groundwater system, which has attracted considerable attention from environmental protection organizations. However, the origin and geochemical evolution of groundwater in the Haolebaoji watershed have not been revealed. In this study, the Haolebaoji watershed is selected as the typical study area to investigate hydrogeochemical evolution under the intensive groundwater exploitation. Groundwater samples were collected and tested for major ions and stable isotopes (δ18O, δD). Various approaches including the ion proportional relationship diagram, chlor-alkali index, saturation index, Gibbs diagram, and principal factor analysis were used to reveal the hydrogeochemical processes regulating the groundwater geochemistry. The groundwater in the study area is divided into five hydrochemical types according to the Piper diagram. It was found that the chemical composition of groundwater in the study area is mainly controlled by the dissolution of calcite, dolomite, gypsum, and halite. The cation exchange intensity gradually increased with the flow of groundwater from the recharge to the discharge area. Rock weathering plays a controlling role in the formation of groundwater geochemistry, but it is also controlled by evaporative crystallization in some runoff and discharge areas. Groundwater is predominantly recharged by modern local atmospheric precipitation, and deep wells receive water supply during cold periods. The study findings provide important information for the development of sustainable groundwater management strategies for the Ordos Energy Base.

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“…Strong acids exceeding weak ac ids (5). Carbonate hardness exceeds 50% (6). Non-carbonate hardness exceeds 50% (7).…”

Section: Water Chemistrymentioning

confidence: 99%

“…The natural ecological environment and human socioeconomic development in arid and semiarid regions are strongly dependent on groundwater resources [1][2][3][4][5][6][7]. Changes in the groundwater environment play a pivotal role in the economic and ecological stability in these areas [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Evolution of Hydrogeochemistry in the Haolebaojinao Watershed of the Ordos Basin, China

Zhang

Han

et al. 2023

Sustainability

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“…The δ 18 O values of groundwater are enriched by surface water recharge (Wadi Igrounzar), while the variation of Cl − concentrations depends on the salinity of the infiltration water that is ultimately attached to the water table. Infiltration water salinity is derived from both the surface water and the soil along the paths [43,44]. Furthermore, independently of the isotopic exchange, high concentrations of Cl − with low values of δ 18 O are associated with the processes of salt accumulation inside the aquifer (mineral dissolution and transpiration) as in samples El 16 and El 17.…”

Section: Environmental Isotopes (δ 2 H and δ 18 O)mentioning

confidence: 99%

Geochemical and isotopic evidence of groundwater salinization processes in the Essaouira region, north-west coast, Morocco

et al. 2021

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The city of Essaouira is located along the north-west coast of Morocco, where groundwater is the main source of drinking, domestic and agricultural water. In recent decades, the salinity of groundwater has increased, which is why geochemical techniques and environmental isotopes have been used to determine the main sources of groundwater recharge and salinization. The hydrochemical study shows that for the years 1995, 2007, 2016 and 2019, the chemical composition of groundwater in the study area consists of HCO3–Ca–Mg, Cl–Ca–Mg, SO4–Ca and Cl–Na chemical facies. The results show that from 1995 to 2019, electrical conductivity increased and that could be explained by a decrease in annual rainfall in relation to climate change and water–rock interaction processes. Geochemical and environmental isotope data show that the main geochemical mechanisms controlling the hydrochemical evolution of groundwater in the Cenomanian–Turonian aquifer are the water–rock interaction and the cation exchange process. The diagram of δ2H = 8 * δ18O + 10 shows that the isotopic contents are close or above to the Global Meteoric Water Line, which suggests that the aquifer is recharged by precipitation of Atlantic origin. In conclusion, groundwater withdrawal should be well controlled to prevent groundwater salinization and further intrusion of seawater due to the lack of annual groundwater recharge in the Essaouira region.

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Assessment of groundwater quality using hydrochemical process, GIS and multivariate statistical analysis at central Rif, North Morocco

Benyoussef,

Arabi,

El Yousfi

et al. 2024

Environ Earth Sci

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This study investigated groundwater in the central Rif region of northern Morocco by analysing 55 water sampling points to assess its physicochemical and hydrogeochemical properties. Through hydrochemical analysis, GIS spatial exploration, and multivariate statistical analysis, a direct correlation was found between EC, TDS, and major ions, influencing overall water mineralization. The key findings included pH levels ranging from 6.10 to 8.52, EC from 828 to 4581 μS/cm, and varying concentrations of Ca2+, Mg2+, Na+, K+, HCO2–, Cl–, N–NO2–, and SO42–. Notably, TDS and TH ranged from 647.19–3609.36 mg/L and 64.23–1051.24 mg/L, respectively, with a significant portion of samples exceeding WHO guidelines, particularly chloride (61.81%), sulfate (92.72%), and nitrate (12.72%) samples. The Piper diagram highlights sodium chlorides (Na–Cl) as the predominant chemical facies (70.9%), while the Gibbs diagram emphasizes the impact of evaporation on water chemistry dynamics. This study revealed the complex influence of geological and anthropogenic factors on groundwater quality, potentially leading to seawater intrusion in coastal aquifers. The observed high mineralization and hardness levels, in addition to mild alkalinity, pose public health risks, underscoring the need for continuous monitoring and sustainable management practices in coastal groundwater management to protect human health and the environment.

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Hydrochemical and isotopic assessment for characterizing groundwater quality and recharge processes under a semi arid area: Case of the Haouz plain aquifer (Central Morocco)

Cited by 8 publications

References 12 publications

Evolution of Hydrogeochemistry in the Haolebaojinao Watershed of the Ordos Basin, China

Evolution of Hydrogeochemistry in the Haolebaojinao Watershed of the Ordos Basin, China

Geochemical and isotopic evidence of groundwater salinization processes in the Essaouira region, north-west coast, Morocco

Assessment of groundwater quality using hydrochemical process, GIS and multivariate statistical analysis at central Rif, North Morocco

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