Approximation of the Boundary-to-Solution Operator for the Groundwater
Transport Equation in a Toth Basin
Abstract
We develop a deep learning approach to learn the boundary-to-solution
operator, i.e., to establish the boundary to steady solution mapping, in
the Toth basin of arbitrary top and bottom topographies and two types of
prescribed boundary conditions.
The machine-learned mapping is represented by a DeepOnet, which takes
the geometrical data and boundary conditions as the inputs and produces
the steady state solution as the output. In this approach, we
approximate the top and bottom boundaries by either truncated Fourier
series or piecewise linear representations. The DeepOnet maps directly
the finite dimensional representations of the boundaries to the steady
state solution of the ground water transport equation in the Toth basin.
We present two different implementations of the DeepOnet: 1) the Toth
basin is embedded in a rectangular computational domain, and 2) the Toth
basin with arbitrary top and bottom boundaries is mapped into a
rectangular computational domain via a nonlinear transformation. We
implement the DeepOnet with respect to the Dirichlet and Robin boundary
condition at the top and the Neumann boundary condition at the
impervious bottom boundary, respectively. Both implementations yield the
same results, showcasing a new deep learning approach to study ground
water transport phenomena.