Implementation of a GPU-enhanced multiclass soil erosion model based on
the 2D shallow water equations in the software Iber
Abstract
Physically-based soil erosion models are valuable tools for the
understanding and efficient management of soil erosion related problems
at the basin and river reach scales, as soil loss, muddy floods,
freshwater pollution or reservoir siltation, among others. We present
the implementation of a new fully distributed multiclass soil erosion
module. The model is based on a 2D finite volume solver (Iber+) for the
2D shallow water equations that computes the overland flow water depths
and velocities. From these, the model evaluates the transport of
sediment particles due to bed load and suspended load, including
rainfall-driven and runoff-driven erosion processes, and using
well-established physically-based formulations. The evolution of the
mass of sediment particles in the soil layer is computed from a mass
conservation equation for each sediment class. The solver is implemented
using High Performance Computing techniques that take advantage of the
computational capabilities of standard Graphical Processing Units,
achieving speed-ups of two orders of magnitude relative to a sequential
implementation on the CPU. We show the application and validation of the
model at different spatial scales, ranging from laboratory experiments
to meso-scale catchments.