Coupling saturated and unsaturated flow: comparing the iterative and the non-iterative approach

Abstract. Fully integrated three-dimensional (3D) physically based hydrologic models usually require many computational resources. For applications, simplified can be a cost-effective alternative. The 3D of subsurface flow are often by coupling 2D groundwater model with multiple 1D for the unsaturated zone. crucial part such is between two compartments. In this work we compare approaches coupling. One iterative where zone go down to impervious bottom aquifer, and other one non-iterative uses moving lower boundary context also propose new way treating specific yield, which plays role in linking model. Both applied three test cases increasing complexity analyzed terms accuracy speed compared fully runs. approach faster but does not yield good parameters all cases, whereas gives results cases. Which strategy depends on requirements: vs. accuracy.