Coupled surface-subsurface flow model
When investigating the fate of flow in the Trinity River Delta (TX), evidence revealed possible contribution to the surface water budget from the subsurface. Thus the FrehdC model is being further developed to enable simulation of surface-subsurface flow exchange.
As a first step, a novel numerical solution to the 1D Richards equation is proposed to achieve conservative, efficient and robust simulations for variably-saturated subsurface flow. The new method applies a predictor-corrector type numerical scheme with a post-allocation procedure to enforce mass conservation. This method is still being improved to enable 3D simulation with coupled surface hydrodynamics. The figure below shows validation of the proposed method (PCA) against Hydrus-1D and Warrick's analytical solution using an infiltration problem.
For more info:
Li, Z., Ozgen, I. and Maina, F.Z., 20XX, A mass-conservative predictor-corrector solution to the 1D Richards equation with adaptive time control, Journal of Hydrology, under review