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Abstract：
The groundwater resources in different areas of Pakistan are heading towards depletion along with the deterioration of quality due to over-abstraction and urbanization. The main focus of this study is to map the current hydrostratigraphical and hydraulic conditions of the late Quaternary aquifers in the central part of Thal Doab of Punjab Plains. To achieve the target, a comprehensive approach was employed combining geophysical investigations using electrical resistivity surveys (ERS) and physiochemical analysis of groundwater specimens collected from the study area. Careful calibration of resistivity models was performed by comparing them with lithologs to ensure their accuracy. The current groundwater conditions were assessed through thirty vertical electrical soundings (VES) using the Schlumberger electrode configuration up to 300m of AB/2. The interpreted results revealed the presence of four to six geo-electric sublayers comprising the intermixing layers of clay, silt, sand, gravel, and kankar inclusions. These layers exhibited very low (<20 Ω-m) to very high (>230 Ω-m) resistivity zones at various depth intervals. The developed 2D/3D models of aquifer systems identify the promising areas of good/fresh quality groundwater in the regions characterized by medium to very high resistivity mainly within the sand with gravel layers. However, lower resistivity values indicate the presence of marginally suitable/fair and saline/brackish groundwater showing the existence of fine sediments such as clays/silts. Additionally, twenty groundwater samples were collected to assess various parameters including pH, TDS, arsenic, fluoride, iron, nitrate, and nitrite. The spatial distribution of these parameters was visualized using 2D maps. The suitability of the groundwater for drinking consumption was evaluated in accordance with WHO guidelines.
摘要：
由于过度开采和城市化，巴基斯坦不同地区的地下水资源正在枯竭，质量也在恶化。这项研究的主要重点是绘制旁遮普平原ThalDoab中部第四纪晚期含水层的当前水文地层和水力条件。为了实现目标，采用了一种综合方法，将使用电阻率调查（ERS）的地球物理调查和从研究区域收集的地下水标本的理化分析相结合。通过将电阻率模型与岩性进行比较来仔细校准电阻率模型，以确保其准确性。使用高达300mAB/2的斯伦贝谢电极配置，通过30次垂直电测深（VES）评估了当前的地下水状况。解释结果表明，存在四到六个包含粘土混合层的地电子层，淤泥,沙子,砾石,和kankar夹杂物。这些层在各种深度间隔处表现出非常低(<20Ω-m)至非常高(>230Ω-m)的电阻率区。已开发的含水层系统的2D/3D模型确定了具有中等至非常高电阻率的区域中优质/新鲜地下水的有希望的区域，主要是在具有砾石层的沙子中。然而,较低的电阻率值表明存在少量合适的/普通的和盐水/微咸的地下水，表明存在细沉积物，如粘土/粉砂。此外,收集了20个地下水样本以评估各种参数，包括pH值，TDS,砷,氟化物,铁,硝酸盐,和亚硝酸盐。使用2D图可视化了这些参数的空间分布。根据世卫组织准则评估了地下水是否适合饮用。
