def test_properties_phi_fraction_fines_LS():
"""
BedrockLandslider should throw an error when phi/fraction_fines_LS < 0 or phi > 0
"""
# Make a raster model grid and create a plateau
n_rows = 5
n_columns = 5
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
mg.add_zeros("topographic__elevation", at="node")
mg.add_zeros("soil__depth", at="node")
mg.add_zeros("bedrock__elevation", at="node")
PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
# instantiate the slider
with pytest.raises(ValueError):
BedrockLandslider(mg, phi=-0.2)
# instantiate the slider
with pytest.raises(ValueError):
BedrockLandslider(mg, phi=1.2)
# instantiate the slider
with pytest.raises(ValueError):
BedrockLandslider(mg, fraction_fines_LS=-0.2)
# instantiate the slider
with pytest.raises(ValueError):
BedrockLandslider(mg, fraction_fines_LS=1.2)
def test_sliding_plain():
"""
Test that if BedrockLandslider maths are sound and follow the Culmann theory
"""
# Make a raster model grid and create a plateau
n_rows = 5
n_columns = 5
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
z = mg.add_zeros("topographic__elevation", at="node")
s = mg.add_zeros("soil__depth", at="node")
b = mg.add_zeros("bedrock__elevation", at="node")
# make plateau at 10m
b += 10
# Lower boundary cell to 0
b[2] = 0
z[:] = b + s
fd = PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
hy = BedrockLandslider(mg, landslides_return_time=1)
# run flow director and BedrockLandslider for one timestep
fd.run_one_step()
hy.run_one_step(dt=1)
# After one timestep, we can predict eactly where the landslide will occur.
# The return time is set to 1 year so that probability for sliding is 100%
# The angle of internal driction is 1m/m, the topographical gradient is 10 m/m
# At cardinal cells, the sliding plain will be at (1+10)/2 = 5.5 m/m.
# With a dx of 1, the cardial cell next to the critical sliding node must
# be 5.5 m and the diagonal one at 5.5 * sqrt(2) = 7.8 m
err_msg = "Error in the calculation of the sliding plain"
testing.assert_almost_equal(
[5.5 * np.sqrt(2), 5.5, 5.5 * np.sqrt(2)], z[6:9], decimal=5, err_msg=err_msg
)
def test_mass_balance_porosity_suspension():
"""
Test is mass balance is conserved during sliding events.
Test for soils with given porosity phi and where none of the sediment is
evacuated as suspended sediment.
"""
# %%
# Make a raster model grid and create a plateau
n_rows = 9
n_columns = 9
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
z = mg.add_zeros("topographic__elevation", at="node")
s = mg.add_zeros("soil__depth", at="node")
b = mg.add_zeros("bedrock__elevation", at="node")
# make plateau at 10m
b += 10
# Elevate central node
b[40] = 10
# Create slope at margin so that sediment will be evacuated
b[mg.boundary_nodes] = 0
z[:] = b + s
fd = PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
# Instanciate the slider, but this time provide the node at which landslides
# should occur (node 2)
phi = 0.3
fraction_fines_LS = 0.5
hy = BedrockLandslider(
mg,
angle_int_frict=1,
landslides_return_time=1,
landslides_on_boundary_nodes=True,
phi=phi,
fraction_fines_LS=fraction_fines_LS,
)
# Assume equal bulk density for rock and soil
total_vol_before = np.sum(b) + np.sum(s) * (1 - phi)
# Keep track of total volumes evacuated
vol_SSY_tot = 0
V_leaving_tot = 0
# Run for some time
for _ in range(5):
fd.run_one_step()
vol_SSY, V_leaving = hy.run_one_step(dt=1)
vol_SSY_tot += vol_SSY
V_leaving_tot += V_leaving
total_vol_after = np.sum(b) + np.sum(s) * (1 - phi) + vol_SSY_tot + V_leaving_tot
# Check mass balance
err_msg = "Mass balance not okey"
testing.assert_almost_equal(
total_vol_before, total_vol_after, decimal=5, err_msg=err_msg
)
def test_sliding_evolution():
"""
Test that if BedrockLandslider is run for a long enough time, slopes evolve to the
angle of internal friction
"""
# Make a raster model grid and create a plateau
n_rows = 5
n_columns = 5
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
z = mg.add_zeros("topographic__elevation", at="node")
s = mg.add_zeros("soil__depth", at="node")
b = mg.add_zeros("bedrock__elevation", at="node")
# make plateau at 10m
b += 10
# Lower boundary cell to 0
b[2] = 0
z[:] = b + s
fd = PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
# Instanciate the slider, but this time provide the node at which landslides
# should occur (node 2)
hy = BedrockLandslider(
mg,
angle_int_frict=1,
landslides_return_time=0.01,
landslides_on_boundary_nodes=True,
critical_sliding_nodes=[2],
)
# run flow director and BedrockLandslider for long enough so that surface evolves
# towards the angle of internal friction timestep
for _ in range(50):
fd.run_one_step()
hy.run_one_step(dt=1)
# After 50 iterations, landslide erosion starting fromnode 2 evolves to a
# known slope, equal to the angle of internal friction, multiplied by the
# distance from node 2 giving:
topo_cal = np.array(
[
[2.0, 1.0, 0.0, 1.0, 2.0],
[2.23606798, 1.41421356, 1.0, 1.41421356, 2.23606798],
[2.82842712, 2.23606798, 2.0, 2.23606798, 2.82842712],
[3.60555128, 3.16227766, 3.0, 3.16227766, 3.60555128],
[4.47213595, 4.12310563, 4.0, 4.12310563, 4.47213595],
]
).flatten()
err_msg = "Slope is not evolving to theoretical value"
testing.assert_almost_equal(topo_cal, z, decimal=5, err_msg=err_msg)
def test_boundary_nodes():
# %%
"""
Test that if BedrockLandslider cannot make or initate landslides at boundary nodes,
it doesn't
"""
# Make a raster model grid and create a plateau
n_rows = 5
n_columns = 5
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
z = mg.add_zeros("topographic__elevation", at="node")
s = mg.add_zeros("soil__depth", at="node")
b = mg.add_zeros("bedrock__elevation", at="node")
# make plateau at 10m
b += 10
# Lower boundary cell to 0
b[2] = 0
z[:] = b + s
ini_topo_bd = z[mg.boundary_nodes]
fd = PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
# Instanciate the slider, but this time provide the node at which landslides
# should occur (node 2)
hy = BedrockLandslider(
mg,
angle_int_frict=1,
landslides_return_time=0.01,
landslides_on_boundary_nodes=False,
critical_sliding_nodes=[2],
)
# run flow director and BedrockLandslider for long enough so that surface evolves
# towards the angle of internal friction timestep
for _ in range(5):
fd.run_one_step()
hy.run_one_step(dt=1)
# Final topo at boundary nodes should be inital topo
err_msg = "No landslide erosion allowed at boundary nodes"
testing.assert_almost_equal(
ini_topo_bd, z[mg.boundary_nodes], decimal=5, err_msg=err_msg
)
def test_inputFields_bedrock():
"""
BedrockLandslider should create the bedrock__elevation field when not provided
"""
n_rows = 5
n_columns = 5
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
mg.add_zeros("topographic__elevation", at="node")
mg.add_zeros("soil__depth", at="node")
# mg.add_zeros("bedrock__elevation", at='node')
PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
BedrockLandslider(mg)
# instantiate the slider
assert "bedrock__elevation" in mg.at_node
def test_inputFields_soil():
"""
BedrockLandslider should throw an error when the soil__depth field is not provided
"""
n_rows = 5
n_columns = 5
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
mg.add_zeros("topographic__elevation", at="node")
# mg.add_zeros("soil__depth", at='node')
mg.add_zeros("bedrock__elevation", at="node")
PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
# instantiate the slider
with pytest.raises(FieldError):
BedrockLandslider(mg)
def test_inputFields_flowRouter():
"""
BedrockLandslider should throw an error when topograhy is not equal to the sum of
bedrock and soil thickness
"""
# Make a raster model grid and create a plateau
n_rows = 5
n_columns = 5
spacing = 1
mg = RasterModelGrid((n_rows, n_columns), xy_spacing=spacing)
mg.add_zeros("topographic__elevation", at="node")
mg.add_zeros("soil__depth", at="node")
b = mg.add_zeros("bedrock__elevation", at="node")
# make plateau at 10m
b += 10
PriorityFloodFlowRouter(mg, separate_hill_flow=True, suppress_out=True)
# instantiate the slider
with pytest.raises(RuntimeError):
BedrockLandslider(mg)