The deterioration of water quality in shallow groundwater systems over the past decades has attracted increased amounts of attention from hydrogeologists. Groundwater vulnerability and its changes are the factors that cause groundwater deterioration. Combining of the mean residence times (MRTs) with chemical characteristics of groundwater can be applied to understand groundwater vulnerability and its changes. The groundwater MRTs ranged from 6 to 180 years, with MRTs of 6 to 77 years in the shallow aquifer. Spatial distribution of groundwater MRTs suggested that young groundwater trended to extend. Relatively uniform MRTs and concentrations of ions were found above the main pumped well depth. High concentrations of ions (K⁺, Na⁺, Ca²⁺, Mg²⁺, HCO₃⁻, Cl^- and SO₄^2-) were mainly distributed in the western piedmont plain areas with short turnover time but with low productivity, meaning that the aquifer is susceptible to human activities and hardly migrate out. Elevated concentrations of nitrate and others ions (such as K⁺, Ca²⁺, Cl^- and SO₄^2-) also were observed in moderately old groundwater (20 < MRTs < 80 years), indicating that some mixing with recent water within MRTs < 20 years likely occurs through vertical drainage from the upper to deeper in the single aquifer and that lateral flow occurs along flow paths towards the piezometric depressions caused by the pumping in urban areas. Slightly elevated HCO₃⁻ and K⁺ were found at east of the areas with long residence times suggested that water-salt equilibrium had also been disrupted. Therefore, the anthropogenic influence exceeded the natural attenuation in the current groundwater environment on the piedmont plain. And the Shijiazhuang groundwater system was identified to be tending more vulnerable under anthropogenic influence. Some measures must be taken to significantly reduce groundwater withdrawal and pollutant discharge.

过去几十年浅层地下水系统水质的恶化引起了水文地质学家越来越多的关注。地下水脆弱性及其变化是导致地下水恶化的因素。将平均停留时间 (MRT) 与地下水的化学特征相结合，可用于了解地下水的脆弱性及其变化。地下水 MRT 的寿命为 6 至 180 年，浅层含水层的 MRT 为 6 至 77 年。地下水 MRT 的空间分布表明年轻的地下水有扩展的趋势。在主泵井深度上方发现了相对均匀的 MRT 和离子浓度。高浓度离子（K ⁺、Na ⁺、Ca ²⁺、Mg ²⁺、HCO ₃ ^-、Cl ^-和SO ₄ ^2- ) 主要分布在西部山麓平原地区，周转时间短但生产力低，意味着含水层易受人类活动影响，难以迁移出。硝酸盐和其他离子（如 K ⁺、Ca ²⁺、Cl ^-和 SO ₄ ^{2- ）的}浓度升高) 也在中等古老的地下水（20 < MRT < 80 年）中观察到，表明在 MRT < 20 年内与最近的水有一些混合可能是通过从单一含水层的上部到更深处的垂直排水发生的，并且侧向流沿流动发生通往城市地区抽水造成的测压洼地的路径。HCO ₃ ^-和 K ⁺略微升高在停留时间长的区域以东发现了水盐平衡，这表明水盐平衡也被破坏了。因此，人为影响超过了山前平原当前地下水环境的自然衰减。石家庄地下水系统被确定在人为影响下更加脆弱。必须采取一些措施，显着减少地下水抽取和污染物排放。