The Zeroud Plio-quaternary aquifer constitutes the most important fresh groundwater reservoirs in the Kairouan plain, Central Tunisia. Since the impoundment of the Sidi Saad Dam, in the eighties, the hydrodynamic functioning of the referred aquifer system has been affected irreversibly and has resulted in a continuous decline of water level and degradation of groundwater quality. The present investigation, which uses a set of geochemical and isotopic tracers, reflects that artificial recharge has engendered an increase of the water table essentially in the right bank of the wadi. Hydro-chemical tracing of Zeroud waters has shown that the relatively high concentrations of major ions result mainly from natural processes related to water–rock interaction, such as dissolution of evaporates (halite, gypsum and anhydrite), cation exchange, dedolomitisation, and anthropogenic processes, mainly in relation with the return flow of irrigation waters. Moreover, the released waters from Sidi Saad Dam have engendered groundwater salinization and contamination. The use of water quality indexes (WQI), i.e., the EC, %Na and SAR demonstrates that almost all samples are doubtful to unsuitable for irrigation purposes and may result in soils texture degradation. Soluble sodium percentage values vary largely from 25.5 to 70.9% indicating that all the groundwater samples have unsuitable quality for irrigation uses. The isotopically enriched groundwater samples lend support to the effect of recharge by evaporated dam water during releases operations. Tritium isotope contents which vary in a wide range from 0 to 15.3 UT provide insight into the impact of the construction of the Sidi Saad Dam on groundwater recharge. This may be provided through the reduction of the natural recharge amount ensuring by the Zeroud wadi (lineal recharge) and an increase of the spatial recharge component. Therefore, multi-chemical elements combined with isotopes (³H, ²H, ¹⁸O) analysis have been used successfully to discriminate three recharge areas according to the geologic and lithologic characteristics of the studied region.

Zeroud Plio-第四纪含水层构成了突尼斯中部凯鲁万平原最重要的淡水淡水水库。自 80 年代 Sidi Saad 大坝蓄水以来，所涉含水层系统的水动力功能受到不可逆转的影响，导致水位持续下降和地下水质量下降。目前的调查使用了一套地球化学和同位素示踪剂，反映了人工补给导致了河道右岸地下水位的增加。Zeroud 水域的水化学追踪表明，主要离子的相对高浓度主要来自与水-岩石相互作用有关的自然过程，例如蒸发物（岩盐、石膏和硬石膏）的溶解、阳离子交换、去云石化和人为过程，主要与灌溉水的回流有关。此外，西迪萨阿德大坝释放的水造成地下水盐碱化和污染。使用水质指数（WQI），即 EC、%Na 和 SAR 表明，几乎所有样品都怀疑不适合灌溉目的，并可能导致土壤质地退化。可溶性钠百分比值从 25.5% 到 70.9% 变化很大，表明所有地下水样品的质量都不适合灌溉用途。同位素富集的地下水样本支持泄放作业期间蒸发的大坝水补给的影响。氚同位素含量变化范围从 0 到 15。3 UT 深入了解了 Sidi Saad 大坝的建设对地下水补给的影响。这可以通过减少由 Zeroud wadi（线性补给）确保的自然补给量和增加空间补给分量来提供。因此，与同位素结合的多化学元素（³ H, ² H, ¹⁸ O) 分析已成功用于根据研究区域的地质和岩性特征区分三个补给区。