Coupled model on consolidation and porewater mobilization within low-permeability sediments

Groundwater, a crucial freshwater resource, constitutes over 95% of the world's discovered freshwater. It effectively mitigates the uneven spatial distribution of surface water, prompting the development of industry, agriculture, and human society. In most cases, the exploitation of groundwater resources inevitably involves the consolidation of low-permeability sediments. The mobilization of porewater from it, carrying various chemical components, had leaded to worldwide water quality degradation and endemic diseases. Consequently, close attention and control over the mobilization of porewater from low-permeability sediments during extraction is urgently needed. However, the mobilization of porewater caused by consolidation is often confused with porous medium flow. Existing models considering porewater mobilization during compaction contain incomplete assumptions about porewater flow and solute mobilization within low-permeability sediments, making it challenging to incorporate porewater mobilization from these sediments into reactive solute transport models during groundwater abstraction. Further investigation would benefit grasping water quality evolution during groundwater abstraction and for risk management of clean freshwater resources. In this study, we developed a physical device to simultaneously monitor the consolidation and porewater mobilization in low-permeability sediments. By refining Gibson's large deformation consolidation theory based on experimental observations, we describe both consolidation and porewater mobilization processes within low-permeability sediments under a unified framework. This approach aims to provide new insights and feasible solutions for integrating low-permeability sediments into the watershed-scale three-dimensional groundwater model, particularly for understanding water quality origins in Quaternary aquifers.