Fully Coupled Surface-Subsurface Flow and Transport Model in GeRa Software

In this article, we present a mathematical model for simulating coupled surface-subsurface water flow and solute transport implemented in the GeRa software. The model employs the Richards equation for groundwater flow, the diffusion wave approximation for surface runoff, incorporating Manning’s formula for flow velocity estimation and advection-diffusion equation for both surface and subsurface solute transport. Surface-subsurface coupling is implemented using the first-order exchange approach. Implemented using the INMOST software platform, the model facilitates parallel mathematical modeling, and we assess its parallel efficiency against Borden catchment benchmark. The results demonstrate good agreement with the experimental data as well as good parallel scalability of the model.