On several numerical strategies to solve Richards' equation in heterogeneous media with Finite Volumes

International audienceWe benchmark several numerical approaches building on upstream mobility two-point flux approximation finite volumes to solve Richards' equation in domains made of several rocktypes. Our study encompasses four different different schemes corresponding to different ways to approximate the nonlinear transmission condition systems arising at the interface between different rocks, as well as different resolution strategies based on Newton's method with variable switch. The different methods are compared on filling and drainage test cases with standard nonlinearities of Brooks-Corey and van Genuchten type, as well as with challenging steep nonlinearities