Faculty of Sciences of Tunis, Sedimentary environments, Oil systems and Reservoir characterization Laboratory, University of Tunis El Manar, UR11 ES15, 2092, Tunis, Tunisia.
Center of Water Research and Technologies, Geo-resources Laboratory, Techno-park Borj-Cedria, 273, Soliman, Tunisia.
Environ Sci Pollut Res Int. 2018 Dec;25(36):36306-36327. doi: 10.1007/s11356-018-3473-1. Epub 2018 Oct 27.
The Takelsa phreatic aquifer (Northeastern Tunisia) is an important source of fresh water for different economic sectors in the region that are strongly dependent on groundwater resources but, the aquifer is showing increasing signs of groundwater quality degradation like many other regions in the Mediterranean Basin. By integrating geochemical and multivariate statistical investigation methods, this research aims to identify the main geochemical processes and anthropogenic activities that are responsible for regional groundwater quality evolution, identifying the origins of salinity and nutrients, and their implications for groundwater use forcropirrigation and drinking water supply in order to improve aquifer management practices. The results show that groundwater facies vary from Ca-Mg-SO to Na-Cl water type and that mineralization is strongly controlled by mineral dissolution and cation exchange. The isotopic analyses indicate that groundwater is recharged by rainwater infiltration at higher altitudes and that a cumulative evaporative effect may contribute to local increase of salt content in groundwater. The Water Quality Index (WQI) used to determine the suitability of the Takelsa groundwater for drinking purposes reveals that just half of the groundwater points sampled show good to excellent quality for human consumption. The groundwater quality is also limited for irrigation purposes due to anthropogenic activities existing throughout the region. As groundwater in the studied region is crucial for irrigation and human supply, the identified groundwater quality problems and the identification of the main processes responsible for them should contribute to improve the infrastructure and managementpractices to allow the region to sustainable exploit the available groundwater resources.
塔克莱萨潜水含水层（突尼斯东北部）是该地区不同经济部门的重要淡水来源，这些部门严重依赖地下水资源，但与地中海盆地的许多其他地区一样，该含水层显示出地下水水质恶化的迹象越来越明显。本研究通过整合地球化学和多元统计调查方法，旨在确定主要的地球化学过程和人为活动，这些过程和活动是导致区域地下水质演变的原因，确定盐分和养分的来源及其对灌溉和饮用水供应的地下水利用的影响，以改善含水层管理实践。结果表明，地下水相从 Ca-Mg-SO 型到 Na-Cl 水型变化，矿化度受矿物溶解和阳离子交换的强烈控制。同位素分析表明，地下水是由较高海拔的雨水渗透补给的，累积的蒸发作用可能导致地下水中盐分含量的局部增加。用于确定塔克莱萨地下水是否适合饮用目的的水质指数 (WQI) 表明，只有一半的采样地下水点显示出对人类消费良好到极好的质量。由于整个地区都存在人为活动，地下水的质量也限制了灌溉用途。由于研究区域的地下水对灌溉和人类供应至关重要，因此，确定地下水质量问题及其主要成因应有助于改善基础设施和管理实践，以允许该地区可持续利用现有的地下水资源。
