The development of new analytic elements for transient flow and multiaquifer flow

Area of Science:

• Hydrogeology
• Computational Fluid Dynamics
• Numerical Modeling

Background:

• The analytic element method (AEM) is a powerful tool for groundwater flow modeling.
• Existing AEM formulations face challenges in accurately representing general flow fields with continuous areal inflow/outflow.
• Modeling leakage through confining layers and transient flow conditions requires specialized approaches.

Purpose of the Study:

• To introduce novel analytic line elements for the AEM.
• To enable the accurate modeling of general flow fields with continuously varying areal inflow or outflow.
• To specifically address the simulation of leakage through leaky layers and transient effects in aquifer systems.

Main Methods:

• Development of new analytic line elements within the AEM framework.
• Construction of elements to precisely model leakage from storage beneath linear features.
• Application of the new elements to problems involving leakage and transient flow.
• Demonstration of the elements' capability to model variations in aquifer properties like hydraulic conductivity and base elevation.

Main Results:

• The new analytic line elements accurately model general flow fields with continuous areal inflow/outflow.
• Leakage through leaky layers and transient effects are precisely simulated.
• Singularities in leakage are effectively matched by the approximate solutions provided by the new elements.
• The elements can reproduce flow field rotations due to variations in aquifer properties.

Conclusions:

• The developed analytic line elements represent a significant advancement in the analytic element method.
• These elements offer a precise and efficient way to model complex hydrogeological phenomena, including leakage and transient flow.
• The methodology extends to modeling the impact of spatially varying aquifer properties on flow fields.