  Flows of granular media down a rough inclined plane demonstrate a number of
nonlocal phenomena. We apply the recently proposed nonlocal granular fluidity
model to this geometry and find that the model captures many of these effects.
Utilizing the model's dynamical form, we obtain a formula for the critical
stopping height of a layer of grains on an inclined surface. Using an existing
parameter calibration for glass beads, the theoretical result compares
quantitatively to existing experimental data for glass beads. This provides a
stringent test of the model, whose previous validations focused on driven
steady-flow problems. For layers thicker than the stopping height, the
theoretical flow profiles display a thickness-dependent shape whose features
are in agreement with previous discrete particle simulations. We also address
the issue of the Froude number of the flows, which has been shown
experimentally to collapse as a function of the ratio of layer thickness to
stopping height. While the collapse is not obvious, two explanations emerge
leading to a revisiting of the history of inertial rheology, which the nonlocal
model references for its homogeneous flow response.
