'Carbon Glacier Raster Model Grid\nClosed boundaries in blue, Outlet in white',
var_name='elevation',
var_units='m',
grid_units=('m', 'm'))
# ### Flow routing
# #### Without depression finder/filler
flow_accum = FlowAccumulator(rmg,
surface='topographic__elevation',
flow_director='FlowDirectorD8',
depression_finder=None,
runoff_rate=None)
da, q = flow_accum.accumulate_flow()
imshow_grid(rmg,
'drainage_area',
plot_name='Contributing Area',
var_name='Contributing Area',
var_units='m^2',
grid_units=('m', 'm'))
fig = plt.gcf().set_size_inches(18.5, 10.5)
# #### With depression finder/filler
from landlab.components import DepressionFinderAndRouter
flow_accum = FlowAccumulator(rmg,
surface='topographic__elevation',
def test_lateral_erosion_and_node():
"""
Test that sets up a simple, pre-defined drainage network and compares
the lateral node that is eroded, the volume of lateral eorsion, and the elevation
of the landscape after one timestep to known values.
"""
nr = 5
nc = 5
dx = 1
mg = RasterModelGrid((nr, nc), xy_spacing=dx)
for edge in (
mg.nodes_at_top_edge,
mg.nodes_at_bottom_edge,
mg.nodes_at_left_edge,
mg.nodes_at_right_edge,
):
mg.status_at_node[edge] = CLOSED_BOUNDARY
for edge in mg.nodes_at_bottom_edge:
mg.status_at_node[edge] = FIXED_VALUE_BOUNDARY
z = mg.add_zeros("node", "topographic__elevation")
loading_vector = np.linspace(1, 4, num=nr)
ramp = np.repeat(loading_vector, nc)
# the tweaks to elevation below make lateral node at node 7
z += ramp
z[11] -= 0.9
z[12] -= 0.4
z[8] -= 0.001
fa = FlowAccumulator(
mg,
surface="topographic__elevation",
flow_director="FlowDirectorD8",
runoff_rate=None,
depression_finder=None,
)
latero = LateralEroder(mg, latero_mech="UC", Kv=0.1, Kl_ratio=1.5)
fa.accumulate_flow()
(mg, dzlat) = latero.run_one_step(dt=1.0)
vlname = mg["node"]["volume__lateral_erosion"]
# predicted volume of lateral eorsion
pred_vollat = 0.00045158164
# predicted elevation after 1 time step
pred_zafter = np.array([
1.0,
1.0,
1.0,
1.0,
1.0,
1.75,
1.675,
1.675,
1.6731154,
1.75,
2.5,
1.66418779,
2.06181623,
2.4249,
2.5,
3.25,
3.085,
3.13332738,
3.16868272,
3.25,
4.0,
4.0,
4.0,
4.0,
4.0,
])
testing.assert_array_almost_equal(
mg.at_node["topographic__elevation"],
pred_zafter,
decimal=8,
err_msg="LatEro basic erosion test failed",
verbose=True,
)
testing.assert_array_almost_equal(
vlname[7],
pred_vollat,
decimal=8,
err_msg="LatEro volume lateral erosion failed",
verbose=True,
)
# Set watershed boundary condition - use lowest elevation if basic call fails
rmg.set_watershed_boundary_condition(z)
fa = FlowAccumulator(
rmg,
# surface='topographic__elevation',
flow_director='FlowDirectorD8',
# runoff_rate=None,
# depression_finder='DepressionFinderAndRouter',
# routing='D4'
)
fa.run_one_step()
(da, q) = fa.accumulate_flow()
outlet_node_to_sample = np.argmax(rmg.at_node['drainage_area'])
print('Outlet Node = ' + str(outlet_node_to_sample) + '; Drainage Area= ' +
str(da[outlet_node_to_sample] / 1000000) + ' km^2; Elev = ' +
str(round(z[outlet_node_to_sample], 1)) + ' m')
# For each of the links, there is a tail and head and node.
# Look at tail nodes of all links, and look at node area, find link that connects
#the link number that carries the largest q
outlet_link_to_sample = rmg.links_at_node[outlet_node_to_sample][3]
rmg.links_at_node[outlet_node_to_sample]
imshow_grid_at_node(rmg, 'drainage_area')