Geostatistical Stochastic Simulation of Hydraulic Conductivity and Groundwater Dynamics Interpretation in an Alluvial-Marine Sedimentary System: A Case Study in Beihai City, China

In the realm of scientific water supply and the vigilant monitoring of advancing marine geohazards, the importance of sustainable aquifer management in coastal cities cannot be overstated. Investigating aquifer heterogeneity and the characteristics of coastal groundwater fluctuations serves as an effective approach to unveil the dynamic nature of aquifers. In this study, we simulated discrete geological variables using SISIM and T-PROGS, leveraging data from 8629 sample points across 111 boreholes in Beihai city, southern China. The results demonstrate heightened accuracy in depicting both lateral sediment distribution driven by river dynamics and vertical processes governing hydraulic conductivity coefficients within the aquifer. Our analysis underscores effectiveness of SISIM in reducing initial data requirements without necessitating Gaussian transformation, ensuring broad applicability, while T-PROGS proves suitable in environments characterized by prevalent lateral accumulation. This study employed the fractal method and wavelet analysis to investigate coastal zone groundwater fluctuations. Daily groundwater fluctuations displayed a distinct periodic variation, indicating a biased stochastic traveling pattern and potential short-term predictability. Notably, time-frequency characteristics exhibited a strong correlation with tidal fluctuations at smaller scales (12-24 hours). Additionally, the study provides initial modeling insights into the impact of heterogeneity on groundwater fluctuations.