Abstract Resulting from lithological conditions and anthropogenic activities as fertilizers use and wastewater discharge, high concentrations of chloride ions were revealed in both surface water and groundwater in Lower Soummam valley, situated in the North-Eastern of Algeria. Using geological, hydrogeological and geochemical data, a conceptual model was designed in order to improve understanding of chloride mass movements within the aquifer. A groundwater flow using PMWIN, coupled with a solute transport numerical model using MT3D code was run. Following a steady state stress period, four transient stress periods were added in order to simulate groundwater level evolution from 2011 to 2030. Groundwater withdrawals, providing from the National Plan of Water, were increased and vertical recharge rate was progressively reduced. Respecting an optimal management of water resources suitable for arid and semi-arid watersheds, successive tests have been conducted in order to mitigate the influence of high pumping rates and low recharge conditions. Recognized as a major term in water budget, water inflows from lateral boundaries representing 54.4%. At the river–aquifer interface, water was exchanged in both upward and downward representing 18% of the total amount of inflow. In coherence with experimental data, simulations indicate an impact of exchange fluxes across the river-aquifer interface. The Cl model simulations show a substantial decrease of Cl loads. According to good hydraulic properties, 90% of simulated wells show a gradual decline in their calculated concentrations, almost located on El Kseur-Oued Ghir pathway. Simulation results could be integrated in the future water resource management plan of Soummam Valley. Such a predictive model, it will be used to lay down water quality restoration strategy.

中文翻译：

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阿尔及利亚东北部贝贾亚 Soummam 山谷下游冲积含水层的地下水流和氯离子迁移模型

摘要 由于岩性条件和化肥使用和废水排放等人为活动，在阿尔及利亚东北部的下苏曼河谷地表水和地下水中都发现了高浓度的氯离子。使用地质、水文地质和地球化学数据，设计了一个概念模型，以提高对含水层内氯化物质量运动的理解。运行使用 PMWIN 的地下水流以及使用 MT3D 代码的溶质运移数值模型。在稳态压力期之后，为了模拟 2011 年至 2030 年的地下水位演变，添加了四个瞬态压力期。增加了国家水计划提供的地下水抽取量，并逐渐降低了垂直补给率。考虑到适合干旱和半干旱流域的水资源优化管理，已经进行了连续测试，以减轻高抽水率和低补给条件的影响。作为水收支中的一个主要术语，来自横向边界的水流入占 54.4%。在河流-含水层界面，水向上和向下交换，占总流入量的 18%。与实验数据一致，模拟表明跨河流-含水层界面的交换通量的影响。Cl 模型模拟显示 Cl 负载显着降低。根据良好的水力特性，90% 的模拟井显示其计算浓度逐渐下降，几乎位于 El Kseur-Oued Ghir 通道。模拟结果可以整合到苏曼河谷未来的水资源管理计划中。这样的预测模型，将用于制定水质恢复策略。