Evaluation of groundwater management strategies by optimization under land subsidence constraints

Land subsidence is one of the most critical consequences of groundwater depletion, underscoring the need for management tools capable of evaluating how extraction decisions affect both aquifer conditions and ground deformation. Computational optimization models provide a powerful means to support such decision-making; however, most groundwater management studies addressing subsidence-prone systems impose constraints solely on aquifer drawdown, without explicitly controlling land subsidence. Here we develop an optimization framework that integrates management constraints on both aquifer drawdown and land subsidence rate, enabling simultaneous control of hydraulic conditions and deformation. Three constraint strategies were defined and applied to a simulated aquifer–aquitard system to evaluate the coupled response between aquifer drawdown and aquitard compression. The methodology involved formulating optimization models with alternative constraints, simulating multi-year scenarios, and comparing their impacts on groundwater dynamics and land subsidence behavior. Results demonstrate that the choice of management constraints strongly influences aquifer depletion, aquitard response, and total land subsidence. When only drawdown is constrained, total settlement reaches roughly 10% of the aquitard thickness. Introducing a subsidence-rate constraint limits settlement to about 1.25%, while applying only a subsidence-rate constraint reduces settlement to 0.04% of the aquitard thickness. However, a trade-off would arise between controlling land subsidence and supplying groundwater as the volume of water produced through the management period is also reduced. These outcomes highlight the effectiveness of integrated management constraints and illustrate how integrated constraints can inform groundwater management decisions in subsidence-prone settings. • Groundwater management strategies incorporating constraints from the groundwater management model. • Subsidence propagation analysis in highly compressible aquitards using Duhamel's theorem. • Evaluation of total land subsidence under different management scenarios.