Influenced by paleoclimate, paleogeography and hydrogeology, groundwater with different total dissolved solids (TDS) levels, such as freshwater, brackish water, saline water and brine, widely occurs across southern Laizhou Bay (SLB) . Due to groundwater overexploitation, several groundwater depression cones have gradually formed since the 1970s, resulting in saline water intrusion. In this study, the multivariate statistical analysis (MSA) approach was adopted to identify the hydrochemical characteristics of shallow groundwater (SG) and deep groundwater (DG) in the SLB. Moreover, we applied Gibbs diagrams, hydrochemical facies evolution diagrams (HFE-Diagram) and ion proportion relations to analyze the factors influencing the hydrochemical characteristics. The results showed that hydrochemical zonation of the various water types (ranging from Ca-HCO₃ to Na-Cl) from south to north was mainly controlled by migration and mixing of saline water with regional groundwater. Based on the MSA results and hydrochemical characteristics, SG functional areas were divided into the groundwater flow zone, intense groundwater mixing zone and groundwater-seawater interaction zone, and DG functional areas were divided into the groundwater flow zone, groundwater mixing zone and underground brine storage zone. Finally, SG and DG groundwater flow evolution models were developed . The comprehensive method proposed in this study combines the MSA approach with regional geological characteristics and provides a reference for the evaluation of complex multiaquifer systems and analysis of the groundwater evolution characteristics in other regions.

受古气候，古地理和水文地质学的影响，莱州湾南部（SLB）广泛分布着不同总溶解固体（TDS）水平的地下水，例如淡水，微咸水，盐水和盐水。由于地下水的过度开采，自1970年代以来逐渐形成了几个地下水低压锥，导致咸水入侵。在这项研究中，采用多元统计分析（MSA）方法来确定SLB中浅层地下水（SG）和深层地下水（DG）的水化学特征。此外，我们应用了吉布斯图，水化学相演化图（HFE-Diagram）和离子比例关系来分析影响水化学特性的因素。从南到北从₃到Na-Cl）主要受咸水与区域地下水的迁移和混合的控制。根据MSA结果和水化学特征，将SG功能区划分为地下水流区，强烈地下水混合区和地下水-海水相互作用区，将DG功能区划分为地下水流区，地下水混合区和地下盐水储存区区。最后，建立了SG和DG地下水流演化模型。本研究提出的综合方法将MSA方法与区域地质特征相结合，为评估复杂的多含水层系统和分析其他区域的地下水演化特征提供了参考。