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EN
Groundwater quality degradation is a pressing concern in semi-arid coastal regions, exemplified by the Ghiss-Nekor aquifer in northeastern Morocco, spanning 100 km2. This study adopts a comprehensive approach, utilizing chloro-alkaline indices, hydrochemical facies diagrams, the water quality index (WQI), and the synthetic pollution index (SPI) to assess the groundwater quality and its evolution. Key findings reveal that the Ghiss-Nekor ground-water is brackish, primarily suitable for irrigation due to high total dissolved solids (TDS). Salinization stems from reverse cation exchange, as indicated by hydrochemical analyses. WQI assessments highlight the inadequacy of this groundwater for drinking purposes, with SPI classifying 54% of wells as moderately polluted. Fine particles mitigate marine intrusion in the northwest. Overlaying land-use and electrical conductivity maps identifies the areas with poor-quality groundwater, notably near an unregulated landfill, a coastal tourist site, and a wastewater treatment facility. Ionic analysis identifies multiple saline sources, with nitrate and sulfate contributions standing out. While the study offers valuable insights, limitations include the need for ongoing data collection and source identification challenges. Nonetheless, the research underscores the urgency of effective water management, particularly around the landfill site situated above permeable deposits, offering an innovative approach with global applicability for addressing groundwater quality issues in semi-arid coastal areas.
EN
Deterioration of water quality is of great concern, particularly in coastal aquifers where it has become difficult to meet water quality standards with appropriate salt content. As groundwater is the only alternative source of freshwater in the coastal plain of Ghiss-Nekor in northern Morocco, there is a need to assess its sustainability and suitability for drinking and irrigation purposes. For this purpose, data obtained from ABHL, corresponding to 13 monitoring wells existing in the downstream part of Ghiss-Nekor aquifer, were gathered and analyzed using a combination of statistical methods and GIS mapping tools. Various qualitative parameters namely; pH, turbidity, salinity, dissolved oxygen, conductivity, Chloride (Cl-), Sulphate (SO4) and some Nitrogen compounds were investigated and compared according to World Health Organization standards. These results suggest that groundwater samples are chemically dominated by chloride anions followed by sulphate anions; high levels of SO4 result from the mineral dissolving of evaporites in addition to the impact of seawater intrusion and the discharge of wastewater without adequate pre-treatment, while Cl- concentrations (408.3–1512.3 mg/L), strongly correlated with electrical conductivity, are related to the impact of seawater intrusion. A few samples along the Nekor River, considered as the aquifer’s recharge zone, showed the lowest salinity levels (<1.5 g/L) compared to the coastal samples which were classified as the most conductive and mineralized (EC greater than 3000 μS/cm) due to the combined impact of mixing with seawater and high evaporation rates. The outcome of this study reveals that the major dissolved anions assessed in the groundwater of the Ghiss-Nekor aquifer do not respect the stipulated criteria in terms of human consumption; therefore, all possible measures should be taken to protect and restore the water quality in this vulnerable coastal aquifer.
EN
Based on the inverse approach and the finite element method, the quality of a reconstructed signal is discussed in this work. The responses caused by a distributed impact on a portion of a composite structure can be recovered using dynamic analysis. The structure is thought to be complex and made up of two different-sized plates made of two different materials. The robustness of the inversion method was studied, as well as the sensitivity of the numerical method compared to modal truncation and sampling of the frequency response function (FRF). Once the FRF had been identified, regularized deconvolution as per generalized singular value decomposition was used to reconstruct the impact signal characteristics. It was revealed that only one mode is required to reconstruct the impact signal.
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