Modeling Aquifer Compaction and Lateral Deformation Due to Groundwater Extraction: A Comparative Study Using Terzaghi’s and Biot’s Theories

Land subsidence caused by groundwater withdrawal remains a significant challenge in urbanized regions, requiring robust predictive models to manage its impact effectively. In this study, a set of coupled partial differential equations is formulated using Biot’s poroelasticity theory and Darcy’s law to model the hydro-mechanical behavior of a multi-aquifer system. The numerical models capture the coupled dynamics of fluid flow and subsurface deformation induced by groundwater table depression. Hydraulic head reductions, vertical compaction, and lateral deformation patterns over a 10-year pumping period are systematically examined. The results manifest that greater hydraulic gradients near geological discontinuities, such as bedrock steps, induce localized deformation and stress redistribution. While Terzaghi’s model effectively predicts vertical compaction in simple systems, Biot’s model accounts for lateral strain and coupled feedback mechanisms, providing a more comprehensive analyses and understanding of subsidence phenomena. This study highlights the importance of coupled hydro-mechanical modeling for accurately predicting land subsidence and offers insights into managing groundwater extraction in geologically complex regions.