def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""Initialize the BasicHyRt."""
# Call ErosionModel's init
super(BasicHyRt,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
contact_zone__width = (self._length_factor *
self.params['contact_zone__width']) # L
self.K_rock_sp = self.get_parameter_from_exponent('K_rock_sp')
self.K_till_sp = self.get_parameter_from_exponent('K_till_sp')
linear_diffusivity = (
(self._length_factor**2) *
self.get_parameter_from_exponent('linear_diffusivity'))
v_sc = self.get_parameter_from_exponent(
'v_sc') # normalized settling velocity. Unitless.
# Set up rock-till
self.setup_rock_and_till(self.params['rock_till_file__name'],
rock_erody_br=self.K_rock_sp,
till_erody_br=self.K_till_sp,
rock_thresh_br=0.0,
till_thresh_br=0.0,
contact_width=contact_zone__width)
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Handle solver option
try:
solver = self.params['solver']
except:
solver = 'original'
# Instantiate an ErosionDeposition ("hybrid") component
self.eroder = ErosionDeposition(self.grid,
K='K_br',
F_f=self.params['F_f'],
phi=self.params['phi'],
v_s=v_sc,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
method='simple_stream_power',
discharge_method='drainage_area',
area_field='drainage_area',
solver=solver)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def test_assertion_error():
"""Test that the correct assertion error will be raised."""
mg = RasterModelGrid(10, 10)
z = mg.add_zeros('topographic__elevation', at='node')
z += 200 + mg.x_of_node + mg.y_of_node + np.random.randn(mg.size('node'))
mg.set_closed_boundaries_at_grid_edges(bottom_is_closed=True, left_is_closed=True, right_is_closed=True, top_is_closed=True)
mg.set_watershed_boundary_condition_outlet_id(0, z, -9999)
fa = FlowAccumulator(mg, flow_director='D8', depression_finder=DepressionFinderAndRouter)
sp = FastscapeEroder(mg, K_sp=.0001, m_sp=.5, n_sp=1)
ld = LinearDiffuser(mg, linear_diffusivity=0.0001)
dt = 100
for i in range(200):
fa.run_one_step()
flooded = np.where(fa.depression_finder.flood_status==3)[0]
sp.run_one_step(dt=dt, flooded_nodes=flooded)
ld.run_one_step(dt=dt)
mg.at_node['topographic__elevation'][0] -= 0.001 # Uplift
assert_raises(AssertionError,
analyze_channel_network_and_plot,
mg,
threshold = 100,
starting_nodes = [0],
number_of_channels=2)
def test_assertion_error():
"""Test that the correct assertion error will be raised."""
mg = RasterModelGrid(10, 10)
z = mg.add_zeros('topographic__elevation', at='node')
z += 200 + mg.x_of_node + mg.y_of_node + np.random.randn(mg.size('node'))
mg.set_closed_boundaries_at_grid_edges(bottom_is_closed=True,
left_is_closed=True,
right_is_closed=True,
top_is_closed=True)
mg.set_watershed_boundary_condition_outlet_id(0, z, -9999)
fa = FlowAccumulator(mg, depression_finder=DepressionFinderAndRouter)
sp = FastscapeEroder(mg, K_sp=.0001, m_sp=.5, n_sp=1)
ld = LinearDiffuser(mg, linear_diffusivity=0.0001)
dt = 100
for i in range(200):
fa.run_one_step()
flooded = np.where(fa.depression_finder.flood_status == 3)[0]
sp.run_one_step(dt=dt, flooded_nodes=flooded)
ld.run_one_step(dt=dt)
mg.at_node['topographic__elevation'][0] -= 0.001 # Uplift
assert_raises(AssertionError,
analyze_channel_network_and_plot,
mg,
threshold=100,
starting_nodes=[0],
number_of_channels=2)
def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""
Initialize the BasicDdHy
"""
# Call ErosionModel's init
super(BasicDdHy,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
# Get Parameters and convert units if necessary:
self.K_sp = self.get_parameter_from_exponent('K_sp')
linear_diffusivity = (
(self._length_factor**2) # L2/T
* self.get_parameter_from_exponent('linear_diffusivity'))
v_s = self.get_parameter_from_exponent('v_sc') # unitless
self.sp_crit = (
self._length_factor # L/T
* self.get_parameter_from_exponent('erosion__threshold'))
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Create a field for the (initial) erosion threshold
self.threshold = self.grid.add_zeros('node', 'erosion__threshold')
self.threshold[:] = self.sp_crit #starting value
# Handle solver option
try:
solver = self.params['solver']
except:
solver = 'original'
# Instantiate an ErosionDeposition component
self.eroder = ErosionDeposition(self.grid,
K=self.K_sp,
F_f=self.params['F_f'],
phi=self.params['phi'],
v_s=v_s,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
sp_crit='erosion__threshold',
method='threshold_stream_power',
discharge_method='drainage_area',
area_field='drainage_area',
solver=solver)
# Get the parameter for rate of threshold increase with erosion depth
self.thresh_change_per_depth = self.params['thresh_change_per_depth']
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def test_assertion_error():
"""Test that the correct assertion error will be raised."""
mg = RasterModelGrid((10, 10))
z = mg.add_zeros("topographic__elevation", at="node")
z += 200 + mg.x_of_node + mg.y_of_node + np.random.randn(mg.size("node"))
mg.set_closed_boundaries_at_grid_edges(
bottom_is_closed=True,
left_is_closed=True,
right_is_closed=True,
top_is_closed=True,
)
mg.set_watershed_boundary_condition_outlet_id(0, z, -9999)
fa = FlowAccumulator(mg,
flow_director="D8",
depression_finder=DepressionFinderAndRouter)
sp = FastscapeEroder(mg,
K_sp=0.0001,
m_sp=0.5,
n_sp=1,
erode_flooded_nodes=True)
ld = LinearDiffuser(mg, linear_diffusivity=0.0001)
dt = 100
for i in range(200):
fa.run_one_step()
sp.run_one_step(dt=dt)
ld.run_one_step(dt=dt)
mg.at_node["topographic__elevation"][0] -= 0.001 # Uplift
with pytest.raises(ValueError):
ChannelProfiler(mg, outlet_nodes=[0], number_of_watersheds=2)
def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""Initialize the BasicVsRt."""
# Call ErosionModel's init
super(BasicVsRt,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
contact_zone__width = (self._length_factor) * self.params[
'contact_zone__width'] # has units length
self.K_rock_sp = self.get_parameter_from_exponent('K_rock_sp')
self.K_till_sp = self.get_parameter_from_exponent('K_till_sp')
linear_diffusivity = (
self._length_factor**
2.) * self.get_parameter_from_exponent('linear_diffusivity')
recharge_rate = (self._length_factor) * self.params[
'recharge_rate'] # has units length per time
soil_thickness = (self._length_factor) * self.params[
'initial_soil_thickness'] # has units length
K_hydraulic_conductivity = (self._length_factor) * self.params[
'K_hydraulic_conductivity'] # has units length per time
# Set up rock-till
self.setup_rock_and_till(self.params['rock_till_file__name'],
self.K_rock_sp, self.K_till_sp,
contact_zone__width)
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Add a field for effective drainage area
if 'effective_drainage_area' in self.grid.at_node:
self.eff_area = self.grid.at_node['effective_drainage_area']
else:
self.eff_area = self.grid.add_zeros('node',
'effective_drainage_area')
# Get the effective-area parameter
self.sat_param = (K_hydraulic_conductivity * soil_thickness *
self.grid.dx) / (recharge_rate)
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerEroder(self.grid,
K_sp=self.erody,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
use_Q=self.eff_area)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def __init__(self, input_file=None, params=None,
BaselevelHandlerClass=None):
"""Initialize the BasicVs."""
# Call ErosionModel's init
super(BasicVs, self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
# Get Parameters:
K_sp = self.get_parameter_from_exponent('K_sp', raise_error=False)
K_ss = self.get_parameter_from_exponent('K_ss', raise_error=False)
linear_diffusivity = (self._length_factor**2.)*self.get_parameter_from_exponent('linear_diffusivity') # has units length^2/time
recharge_rate = (self._length_factor)*self.params['recharge_rate'] # has units length per time
soil_thickness = (self._length_factor)*self.params['initial_soil_thickness'] # has units length
K_hydraulic_conductivity = (self._length_factor)*self.params['K_hydraulic_conductivity'] # has units length per time
# check that a stream power and a shear stress parameter have not both been given
if K_sp != None and K_ss != None:
raise ValueError('A parameter for both K_sp and K_ss has been'
'provided. Only one of these may be provided')
elif K_sp != None or K_ss != None:
if K_sp != None:
self.K = K_sp
else:
self.K = (self._length_factor**(1./3.))*K_ss # K_ss has units Lengtg^(1/3) per Time
else:
raise ValueError('A value for K_sp or K_ss must be provided.')
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(self.grid,
flow_director='D8',
depression_finder = DepressionFinderAndRouter)
# Add a field for effective drainage area
if 'effective_drainage_area' in self.grid.at_node:
self.eff_area = self.grid.at_node['effective_drainage_area']
else:
self.eff_area = self.grid.add_zeros('node',
'effective_drainage_area')
# Get the effective-area parameter
self.sat_param = (K_hydraulic_conductivity*soil_thickness*self.grid.dx)/(recharge_rate)
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerEroder(self.grid,
use_Q=self.eff_area,
K_sp=self.K,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'])
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity = linear_diffusivity)
def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""Initialize the LinDifSPThresholdModel."""
# Call ErosionModel's init
super(BasicTh,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
# Get Parameters and convert units if necessary:
K_sp = self.get_parameter_from_exponent('K_sp', raise_error=False)
K_ss = self.get_parameter_from_exponent('K_ss', raise_error=False)
linear_diffusivity = (
self._length_factor**2.) * self.get_parameter_from_exponent(
'linear_diffusivity') # has units length^2/time
# threshold has units of Length per Time which is what
# StreamPowerSmoothThresholdEroder expects
threshold = self._length_factor * self.get_parameter_from_exponent(
'erosion__threshold') # has units length/time
# check that a stream power and a shear stress parameter have not both been given
if K_sp != None and K_ss != None:
raise ValueError('A parameter for both K_sp and K_ss has been'
'provided. Only one of these may be provided')
elif K_sp != None or K_ss != None:
if K_sp != None:
self.K = K_sp
else:
self.K = (self._length_factor**(
1. / 3.)) * K_ss # K_ss has units Lengtg^(1/3) per Time
else:
raise ValueError('A value for K_sp or K_ss must be provided.')
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(
self.grid,
K_sp=self.K,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
threshold_sp=threshold)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def __init__(self, input_file=None, params=None,
BaselevelHandlerClass=None):
"""Initialize the VSADepthDepThresholdModel."""
# Call ErosionModel's init
super(BasicDdVs, self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
self.K_sp = self.get_parameter_from_exponent('K_sp')
linear_diffusivity = (self._length_factor**2.)*self.get_parameter_from_exponent('linear_diffusivity') # has units length^2/time
recharge_rate = (self._length_factor)*self.params['recharge_rate'] # has units length per time
soil_thickness = (self._length_factor)*self.params['initial_soil_thickness'] # has units length
K_hydraulic_conductivity = (self._length_factor)*self.params['K_hydraulic_conductivity'] # has units length per time
self.threshold_value = self._length_factor*self.get_parameter_from_exponent('erosion__threshold') # has units length/time
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(self.grid,
flow_director='D8',
depression_finder = DepressionFinderAndRouter)
# Add a field for effective drainage area
if 'effective_drainage_area' in self.grid.at_node:
self.eff_area = self.grid.at_node['effective_drainage_area']
else:
self.eff_area = self.grid.add_zeros('node',
'effective_drainage_area')
# Get the effective-area parameter
self.sat_param = (K_hydraulic_conductivity*soil_thickness*self.grid.dx)/(recharge_rate)
# Create a field for the (initial) erosion threshold
self.threshold = self.grid.add_zeros('node', 'erosion__threshold')
self.threshold[:] = self.threshold_value
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(self.grid,
use_Q=self.eff_area,
K_sp=self.K_sp,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
threshold_sp=self.threshold)
# Get the parameter for rate of threshold increase with erosion depth
self.thresh_change_per_depth = self.params['thresh_change_per_depth']
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity = linear_diffusivity)
def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""Initialize the Basic model."""
# Call ErosionModel's init
super(Basic,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
# Get Parameters:
K_sp = self.get_parameter_from_exponent('K_sp', raise_error=False)
K_ss = self.get_parameter_from_exponent('K_ss', raise_error=False)
linear_diffusivity = (
self._length_factor**2.) * self.get_parameter_from_exponent(
'linear_diffusivity') # has units length^2/time
# check that a stream power and a shear stress parameter have not both been given
if K_sp != None and K_ss != None:
raise ValueError('A parameter for both K_sp and K_ss has been'
'provided. Only one of these may be provided')
elif K_sp != None or K_ss != None:
if K_sp != None:
self.K = K_sp
else:
self.K = (self._length_factor**(
1. / 3.)) * K_ss # K_ss has units Lengtg^(1/3) per Time
else:
raise ValueError('A value for K_sp or K_ss must be provided.')
# run the sink filler, only on initiation.
sink_filler = SinkFiller(self.grid, apply_slope=True, fill_slope=1e-3)
sink_filler.run_one_step()
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Instantiate a FastscapeEroder component
self.eroder = FastscapeEroder(self.grid,
K_sp=self.K,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'])
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def __init__(self, input_file=None, params=None,
BaselevelHandlerClass=None):
"""Initialize the StochasticRainThresholdModel."""
# Call ErosionModel's init
super(BasicThSt, self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
K_stoch_sp = self.get_parameter_from_exponent('K_stochastic_sp')
linear_diffusivity = (self._length_factor**2.)*self.get_parameter_from_exponent('linear_diffusivity') # has units length^2/time
# threshold has units of Length per Time which is what
# StreamPowerSmoothThresholdEroder expects
threshold = self._length_factor*self.get_parameter_from_exponent('erosion__threshold') # has units length/time
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(self.grid,
flow_director='D8',
depression_finder = DepressionFinderAndRouter)
# instantiate rain generator
self.instantiate_rain_generator()
# Add a field for discharge
if 'surface_water__discharge' not in self.grid.at_node:
self.grid.add_zeros('node', 'surface_water__discharge')
self.discharge = self.grid.at_node['surface_water__discharge']
# Get the infiltration-capacity parameter
infiltration_capacity = (self._length_factor)*self.params['infiltration_capacity']# has units length per time
self.infilt = infiltration_capacity
# Keep a reference to drainage area
self.area = self.grid.at_node['drainage_area']
# Run flow routing and lake filler
self.flow_router.run_one_step()
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(self.grid,
K_sp=K_stoch_sp,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
threshold_sp=threshold,
use_Q=self.discharge)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity = linear_diffusivity)
def test_depression_finder_bad_instance():
mg = RasterModelGrid((5, 5), spacing=(1, 1))
z = mg.add_field("topographic__elevation",
mg.node_x + mg.node_y,
at="node")
ld = LinearDiffuser(mg, linear_diffusivity=1.)
with pytest.raises(ValueError):
fa = FlowAccumulator(mg, flow_director="D8", depression_finder=ld)
def test_stream_power_save_output(tmpdir):
mg = RasterModelGrid((3, 3), xy_spacing=10.0)
mg.set_status_at_node_on_edges(
right=mg.BC_NODE_IS_CLOSED,
top=mg.BC_NODE_IS_CLOSED,
left=mg.BC_NODE_IS_CLOSED,
bottom=mg.BC_NODE_IS_FIXED_VALUE,
)
mg.add_ones("node", "topographic__elevation")
mg.add_zeros("node", "aquifer_base__elevation")
mg.add_ones("node", "water_table__elevation")
gdp = GroundwaterDupuitPercolator(mg, recharge_rate=1e-4)
hm = HydrologySteadyStreamPower(mg, groundwater_model=gdp)
sp = FastscapeEroder(
mg,
K_sp=1e-10,
m_sp=1,
n_sp=1,
discharge_field="surface_water_area_norm__discharge",
)
ld = LinearDiffuser(mg, linear_diffusivity=1e-10)
rm = RegolithConstantThickness(mg, uplift_rate=0.0)
output = {}
output["output_interval"] = 1000
output["output_fields"] = [
"at_node:topographic__elevation",
"at_node:aquifer_base__elevation",
"at_node:water_table__elevation",
]
output["base_output_path"] = tmpdir.strpath + "/"
output["run_id"] = 0 # make this task_id if multiple runs
mdl = StreamPowerModel(
mg,
hydrology_model=hm,
diffusion_model=ld,
erosion_model=sp,
regolith_model=rm,
total_morphological_time=1e8,
output_dict=output,
)
mdl.run_model()
file = tmpdir.join("0_grid_0.nc")
mg1 = from_netcdf(file.strpath)
keys = [
"topographic__elevation",
"aquifer_base__elevation",
"water_table__elevation",
]
assert isinstance(mg1, RasterModelGrid)
assert set(mg1.at_node.keys()) == set(keys)
assert_equal(mg1.status_at_node, mg.status_at_node)
def __init__(self, input_file=None, params=None,
BaselevelHandlerClass=None):
"""Initialize the BasicDdRt."""
# Call ErosionModel's init
super(BasicDdRt, self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
contact_zone__width = (self._length_factor)*self.params['contact_zone__width'] # has units length
self.K_rock_sp = self.get_parameter_from_exponent('K_rock_sp')
self.K_till_sp = self.get_parameter_from_exponent('K_till_sp')
linear_diffusivity = (self._length_factor**2.)*self.get_parameter_from_exponent('linear_diffusivity')
self.threshold_value = self._length_factor*self.get_parameter_from_exponent('erosion__threshold') # has units length/time
# Set up rock-till
self.setup_rock_and_till(self.params['rock_till_file__name'],
self.K_rock_sp,
self.K_till_sp,
contact_zone__width)
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(self.grid,
flow_director='D8',
depression_finder = DepressionFinderAndRouter)
# Create a field for the (initial) erosion threshold
self.threshold = self.grid.add_zeros('node', 'erosion__threshold')
self.threshold[:] = self.threshold_value
# Instantiate a StreamPowerSmoothThresholdEroder component
self.eroder = StreamPowerSmoothThresholdEroder(self.grid,
K_sp=self.erody,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
threshold_sp=self.threshold)
# Get the parameter for rate of threshold increase with erosion depth
self.thresh_change_per_depth = self.params['thresh_change_per_depth']
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity = linear_diffusivity)
def __init__(self, input_file=None, params=None,
BaselevelHandlerClass=None):
"""Initialize the BasicThRt."""
# Call ErosionModel's init
super(BasicThRt, self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
contact_zone__width = (self._length_factor)*self.params['contact_zone__width'] # has units length
self.K_rock_sp = self.get_parameter_from_exponent('K_rock_sp')
self.K_till_sp = self.get_parameter_from_exponent('K_till_sp')
rock_erosion__threshold = self.get_parameter_from_exponent('rock_erosion__threshold')
till_erosion__threshold = self.get_parameter_from_exponent('till_erosion__threshold')
linear_diffusivity = (self._length_factor**2.)*self.get_parameter_from_exponent('linear_diffusivity')
# Set up rock-till
self.setup_rock_and_till(self.params['rock_till_file__name'],
self.K_rock_sp,
self.K_till_sp,
rock_erosion__threshold,
till_erosion__threshold,
contact_zone__width)
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(self.grid,
flow_director='D8',
depression_finder = DepressionFinderAndRouter)
# Instantiate a StreamPowerSmoothThresholdEroder component
self.eroder = StreamPowerSmoothThresholdEroder(self.grid,
K_sp=self.erody,
threshold_sp=self.threshold,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'])
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity = linear_diffusivity)
def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""Initialize the BasicCv model."""
# Call ErosionModel's init
super(BasicCv,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
K_sp = self.get_parameter_from_exponent('K_sp')
linear_diffusivity = (
self._length_factor**
2.) * self.get_parameter_from_exponent('linear_diffusivity')
self.climate_factor = self.params['climate_factor']
self.climate_constant_date = self.params['climate_constant_date']
time = [0, self.climate_constant_date, self.params['run_duration']]
K = [K_sp * self.climate_factor, K_sp, K_sp]
self.K_through_time = interp1d(time, K)
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Instantiate a FastscapeEroder component
self.eroder = FastscapeEroder(self.grid,
K_sp=K[0],
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'])
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def test_stream_power_run_model_subdivide():
mg = RasterModelGrid((3, 3), xy_spacing=10.0)
mg.set_status_at_node_on_edges(
right=mg.BC_NODE_IS_CLOSED,
top=mg.BC_NODE_IS_CLOSED,
left=mg.BC_NODE_IS_CLOSED,
bottom=mg.BC_NODE_IS_FIXED_VALUE,
)
z = mg.add_ones("node", "topographic__elevation")
z[1] = 1e-15
zb = mg.add_zeros("node", "aquifer_base__elevation")
mg.add_ones("node", "water_table__elevation")
gdp = GroundwaterDupuitPercolator(mg, recharge_rate=1e-4)
hm = HydrologySteadyStreamPower(mg, groundwater_model=gdp)
sp = FastscapeEroder(
mg,
K_sp=1e-10,
m_sp=1,
n_sp=1,
discharge_field="surface_water_area_norm__discharge",
)
ld = LinearDiffuser(mg, linear_diffusivity=1e-10)
rm = RegolithConstantThickness(mg, uplift_rate=0.0)
mdl = StreamPowerModel(
mg,
hydrology_model=hm,
diffusion_model=ld,
erosion_model=sp,
regolith_model=rm,
total_morphological_time=1e8,
maximum_morphological_dt=2e7,
)
mdl.run_step(1e5, dt_m_max=2e4)
assert z[4] < 1.0
assert_equal(z[4] - zb[4], 1.0)
assert_equal(mdl.num_substeps, 5)
elif hard_layer_on_or_off == 0:
k[:] = k_erodible #soft rock
else:
print 'WARNING: MUST SELECT 0 OR 1 IN LAYERED PARAM'
#set up its boundary conditions (left, top, right, bottom is inactive)
mg.set_closed_boundaries_at_grid_edges(False, True, False, True)
# Display initialization message
print('Running ...')
#instantiate the components:
pr = PrecipitationDistribution(input_file)
fr = Flow(mg)
sp = Fsc(mg, input_file)
hd = Diff(mg, input_file)
####################RUN
track_uplift = 0 #track cumulative uplift to know top of hard layer
last_trunc = runtime
for (interval_duration, rainfall_rate) in pr.yield_storm_interstorm_duration_intensity():
if rainfall_rate != 0.:
# note diffusion also only happens when it's raining...
_ = fr.route_flow()
_ = sp.erode(mg, interval_duration, K_if_used='K_values')
_ = hd.diffuse(interval_duration)
track_uplift += uplift_rate * interval_duration #top of beginning surface
mg.at_node['topographic__elevation'][mg.core_nodes] += uplift_rate * interval_duration
this_trunc = pr.elapsed_time // t_plot
if this_trunc != last_trunc: # time to plot a new profile!
print ('Time %d' % (t_plot * this_trunc))
class BasicThSt(_StochasticErosionModel):
"""
A BasicThSt computes erosion using (1) unit stream
power with a threshold, (2) linear nhillslope diffusion, and
(3) generation of a random sequence of runoff events across a topographic
surface.
Examples
--------
>>> from erosion_model import StochasticRainThresholdModel
>>> my_pars = {}
>>> my_pars['dt'] = 1.0
>>> my_pars['run_duration'] = 1.0
>>> my_pars['infiltration_capacity'] = 1.0
>>> my_pars['K_sp'] = 1.0
>>> my_pars['threshold_sp'] = 1.0
>>> my_pars['linear_diffusivity'] = 0.01
>>> my_pars['mean_storm_duration'] = 0.002
>>> my_pars['mean_interstorm_duration'] = 0.008
>>> my_pars['mean_storm_depth'] = 0.025
>>> srt = StochasticRainThresholdModel(params=my_pars)
Warning: no DEM specified; creating 4x5 raster grid
"""
def __init__(self, input_file=None, params=None,
BaselevelHandlerClass=None):
"""Initialize the StochasticRainThresholdModel."""
# Call ErosionModel's init
super(BasicThSt, self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
K_stoch_sp = self.get_parameter_from_exponent('K_stochastic_sp')
linear_diffusivity = (self._length_factor**2.)*self.get_parameter_from_exponent('linear_diffusivity') # has units length^2/time
# threshold has units of Length per Time which is what
# StreamPowerSmoothThresholdEroder expects
threshold = self._length_factor*self.get_parameter_from_exponent('erosion__threshold') # has units length/time
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(self.grid,
flow_director='D8',
depression_finder = DepressionFinderAndRouter)
# instantiate rain generator
self.instantiate_rain_generator()
# Add a field for discharge
if 'surface_water__discharge' not in self.grid.at_node:
self.grid.add_zeros('node', 'surface_water__discharge')
self.discharge = self.grid.at_node['surface_water__discharge']
# Get the infiltration-capacity parameter
infiltration_capacity = (self._length_factor)*self.params['infiltration_capacity']# has units length per time
self.infilt = infiltration_capacity
# Keep a reference to drainage area
self.area = self.grid.at_node['drainage_area']
# Run flow routing and lake filler
self.flow_router.run_one_step()
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(self.grid,
K_sp=K_stoch_sp,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
threshold_sp=threshold,
use_Q=self.discharge)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity = linear_diffusivity)
def calc_runoff_and_discharge(self):
"""Calculate runoff rate and discharge; return runoff."""
if self.rain_rate > 0.0 and self.infilt > 0.0:
runoff = self.rain_rate - (self.infilt *
(1.0 -
np.exp(-self.rain_rate / self.infilt)))
if runoff < 0:
runoff = 0
else:
runoff = self.rain_rate
self.discharge[:] = runoff * self.area
return runoff
def run_one_step(self, dt):
"""
Advance model for one time-step of duration dt.
"""
# Route flow
self.flow_router.run_one_step()
# Get IDs of flooded nodes, if any
flooded = np.where(self.flow_router.depression_finder.flood_status==3)[0]
# Handle water erosion
self.handle_water_erosion(dt, flooded)
# Do some soil creep
self.diffuser.run_one_step(dt)
# calculate model time
self.model_time += dt
# Lower outlet
self.update_outlet(dt)
# Check walltime
self.check_walltime()
def __init__(self,
clock,
grid,
m_sp=0.5,
n_sp=1.0,
water_erodibility=0.0001,
regolith_transport_parameter=0.1,
water_erosion_rule__threshold=0.01,
water_erosion_rule__thresh_depth_derivative=0.0,
**kwargs):
"""
Parameters
----------
clock : terrainbento Clock instance
grid : landlab model grid instance
The grid must have all required fields.
m_sp : float, optional
Drainage area exponent (:math:`m`). Default is 0.5.
n_sp : float, optional
Slope exponent (:math:`n`). Default is 1.0.
water_erodibility : float, optional
Water erodibility (:math:`K`). Default is 0.0001.
regolith_transport_parameter : float, optional
Regolith transport efficiency (:math:`D`). Default is 0.1.
water_erosion_rule__threshold : float, optional
Erosion rule threshold when no erosion has occured
(:math:`\omega_c`). Default is 0.01.
water_erosion_rule__thresh_depth_derivative : float, optional
Rate of increase of water erosion threshold as increased incision
occurs (:math:`b`). Default is 0.0.
**kwargs :
Keyword arguments to pass to :py:class:`ErosionModel`. Importantly
these arguments specify the precipitator and the runoff generator
that control the generation of surface water discharge (:math:`Q`).
Returns
-------
BasicDd : model object
Examples
--------
This is a minimal example to demonstrate how to construct an instance
of model **BasicDd**. For more detailed examples, including
steady-state test examples, see the terrainbento tutorials.
To begin, import the model class.
>>> from landlab import RasterModelGrid
>>> from landlab.values import random
>>> from terrainbento import Clock, BasicDd
>>> clock = Clock(start=0, stop=100, step=1)
>>> grid = RasterModelGrid((5,5))
>>> _ = random(grid, "topographic__elevation")
Construct the model.
>>> model = BasicDd(clock, grid)
Running the model with ``model.run()`` would create output, so here we
will just run it one step.
>>> model.run_one_step(1.)
>>> model.model_time
1.0
"""
# Call ErosionModel"s init
super().__init__(clock, grid, **kwargs)
# verify correct fields are present.
self._verify_fields(self._required_fields)
# Get Parameters and convert units if necessary:
self.m = m_sp
self.n = n_sp
self.K = water_erodibility
if float(self.n) != 1.0:
raise ValueError("Model only supports n equals 1.")
# threshold has units of Length per Time which is what
# StreamPowerSmoothThresholdEroder expects
self.threshold_value = water_erosion_rule__threshold
# Create a field for the (initial) erosion threshold
self.threshold = self.grid.add_zeros("node",
"water_erosion_rule__threshold")
self.threshold[:] = self.threshold_value
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(
self.grid,
m_sp=self.m,
n_sp=self.n,
K_sp=self.K,
threshold_sp=self.threshold,
discharge_field="surface_water__discharge",
erode_flooded_nodes=self._erode_flooded_nodes,
)
# Get the parameter for rate of threshold increase with erosion depth
self.thresh_change_per_depth = (
water_erosion_rule__thresh_depth_derivative)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(
self.grid, linear_diffusivity=regolith_transport_parameter)
class BasicDd(ErosionModel):
r"""**BasicDd** model program.
This model program evolves a topographic surface, :math:`\eta`, with the
following governing equation:
.. math::
\frac{\partial \eta}{\partial t} = -\left(KQ^{m}S^{n}
- \omega_{ct}\left(1-e^{-KQ^{m}S^{n}/\omega_{ct}}\right)\right)
+ D\nabla^2 \eta
where :math:`Q` is the local stream discharge and :math:`S` is the local
slope, :math:`m` and :math:`n` are the discharge and slope exponent
parameters, :math:`K` is the erodibility by water, :math:`D` is the
regolith transport efficiency, and :math:`\omega_{ct}` is the critical
stream power needed for erosion to occur. :math:`\omega_{ct}` changes
through time as it increases with cumulative incision depth:
.. math::
\omega_{ct}\left(x,y,t\right) = \mathrm{max}\left(\omega_c +
b D_I\left(x, y, t\right), \omega_c \right)
where :math:`\omega_c` is the threshold when no incision has taken place,
:math:`b` is the rate at which the threshold increases with incision depth,
and :math:`D_I` is the cumulative incision depth at location
:math:`\left(x,y\right)` and time :math:`t`.
Refer to
`Barnhart et al. (2019) <https://doi.org/10.5194/gmd-12-1267-2019>`_
Table 5 for full list of parameter symbols, names, and dimensions.
The following at-node fields must be specified in the grid:
- ``topographic__elevation``
"""
_required_fields = ["topographic__elevation"]
def __init__(self,
clock,
grid,
m_sp=0.5,
n_sp=1.0,
water_erodibility=0.0001,
regolith_transport_parameter=0.1,
water_erosion_rule__threshold=0.01,
water_erosion_rule__thresh_depth_derivative=0.0,
**kwargs):
"""
Parameters
----------
clock : terrainbento Clock instance
grid : landlab model grid instance
The grid must have all required fields.
m_sp : float, optional
Drainage area exponent (:math:`m`). Default is 0.5.
n_sp : float, optional
Slope exponent (:math:`n`). Default is 1.0.
water_erodibility : float, optional
Water erodibility (:math:`K`). Default is 0.0001.
regolith_transport_parameter : float, optional
Regolith transport efficiency (:math:`D`). Default is 0.1.
water_erosion_rule__threshold : float, optional
Erosion rule threshold when no erosion has occured
(:math:`\omega_c`). Default is 0.01.
water_erosion_rule__thresh_depth_derivative : float, optional
Rate of increase of water erosion threshold as increased incision
occurs (:math:`b`). Default is 0.0.
**kwargs :
Keyword arguments to pass to :py:class:`ErosionModel`. Importantly
these arguments specify the precipitator and the runoff generator
that control the generation of surface water discharge (:math:`Q`).
Returns
-------
BasicDd : model object
Examples
--------
This is a minimal example to demonstrate how to construct an instance
of model **BasicDd**. For more detailed examples, including
steady-state test examples, see the terrainbento tutorials.
To begin, import the model class.
>>> from landlab import RasterModelGrid
>>> from landlab.values import random
>>> from terrainbento import Clock, BasicDd
>>> clock = Clock(start=0, stop=100, step=1)
>>> grid = RasterModelGrid((5,5))
>>> _ = random(grid, "topographic__elevation")
Construct the model.
>>> model = BasicDd(clock, grid)
Running the model with ``model.run()`` would create output, so here we
will just run it one step.
>>> model.run_one_step(1.)
>>> model.model_time
1.0
"""
# Call ErosionModel"s init
super().__init__(clock, grid, **kwargs)
# verify correct fields are present.
self._verify_fields(self._required_fields)
# Get Parameters and convert units if necessary:
self.m = m_sp
self.n = n_sp
self.K = water_erodibility
if float(self.n) != 1.0:
raise ValueError("Model only supports n equals 1.")
# threshold has units of Length per Time which is what
# StreamPowerSmoothThresholdEroder expects
self.threshold_value = water_erosion_rule__threshold
# Create a field for the (initial) erosion threshold
self.threshold = self.grid.add_zeros("node",
"water_erosion_rule__threshold")
self.threshold[:] = self.threshold_value
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(
self.grid,
m_sp=self.m,
n_sp=self.n,
K_sp=self.K,
threshold_sp=self.threshold,
discharge_field="surface_water__discharge",
erode_flooded_nodes=self._erode_flooded_nodes,
)
# Get the parameter for rate of threshold increase with erosion depth
self.thresh_change_per_depth = (
water_erosion_rule__thresh_depth_derivative)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(
self.grid, linear_diffusivity=regolith_transport_parameter)
def update_erosion_threshold_values(self):
r"""Update the erosion threshold at each node based on cumulative
incision so far using:
.. math::
\omega_{ct}\left(x,y,t\right) = \mathrm{max}\left(\omega_c + \\
b D_I\left(x, y, t\right), \omega_c \right)
where :math:`\omega_c` is the threshold when no incision has taken
place, :math:`b` is the rate at which the threshold increases with
incision depth, and :math:`D_I` is the cumulative incision depth at
location :math:`\left(x,y\right)` and time :math:`t`.
"""
# Set the erosion threshold.
#
# Note that a minus sign is used because cum ero depth is negative for
# erosion, positive for deposition.
# The second line handles the case where there is growth, in which case
# we want the threshold to stay at its initial value rather than
# getting smaller.
cum_ero = self.grid.at_node["cumulative_elevation_change"]
cum_ero[:] = (self.z -
self.grid.at_node["initial_topographic__elevation"])
self.threshold[:] = self.threshold_value - (
self.thresh_change_per_depth * cum_ero)
self.threshold[
self.threshold < self.threshold_value] = self.threshold_value
def run_one_step(self, step):
"""Advance model **BasicDd** for one time-step of duration step.
The **run_one_step** method does the following:
1. Creates rain and runoff, then directs and accumulates flow.
2. Assesses the location, if any, of flooded nodes where erosion should
not occur.
3. Assesses if a :py:mod:`PrecipChanger` is an active boundary handler
and if so, uses it to modify the erodibility by water.
4. Calculates detachment-limited, threshold-modified erosion by water.
5. Calculates topographic change by linear diffusion.
6. Finalizes the step using the :py:mod:`ErosionModel` base class
function **finalize__run_one_step**. This function updates all
boundary handlers handlers by ``step`` and increments model time by
``step``.
Parameters
----------
step : float
Increment of time for which the model is run.
"""
# create and move water
self.create_and_move_water(step)
# Calculate the new threshold values given cumulative erosion
self.update_erosion_threshold_values()
# Do some erosion (but not on the flooded nodes)
# (if we're varying K through time, update that first)
if "PrecipChanger" in self.boundary_handlers:
self.eroder.K = (self.K * self.boundary_handlers["PrecipChanger"].
get_erodibility_adjustment_factor())
self.eroder.run_one_step(step)
# Do some soil creep
self.diffuser.run_one_step(step)
# Finalize the run_one_step_method
self.finalize__run_one_step(step)
# accumulated deformation is larger than than the pixel length
v_profile = profile * vmax
accum_disp = profile * float(dxy)
# This is an array for counting how many pixels need to be moved
nshift = np.zeros(np.size(yLocation))
n_buff = 0 # optional extra buffer zone incase you only want to move a subset.
################################################################################
## Last, we instantiate landlab components that will evolve the landscape #####
################################################################################
fr = FlowRouter(rmg) # standard D8 flow routing algorithm
sp = FastscapeEroder(rmg, K_sp='K_sp', m_sp=m, n_sp=n,
threshold_sp=0) # river eroder
lin_diffuse = LinearDiffuser(rmg, linear_diffusivity='D') #linear diffuser
fill = DepressionFinderAndRouter(rmg) #lake filling algorithm
nts = int(num_frames)
ds = xr.Dataset(
data_vars={
'topographic__elevation': (
('time', 'y', 'x'), # tuple of dimensions
np.empty((nts, rmg.shape[0], rmg.shape[1])), # n-d array of data
{
'units': 'meters'
})
}, # dictionary with data attributes
coords={
'x': (
('x'), # tuple of dimensions
threshold_drainage_area = 500 #unclear on what these units are
mg.add_zeros('node','water_depth')
mg.add_zeros('node','water_velocity')
mg.add_zeros('node','corrected_shear_stress')
mg.add_zeros('node', 'erodibility')
mg.add_zeros('node', 'incision_rate')
mg.add_zeros('node', 'num_blocks') #hopefully will contain array of sizes at a given node, one entry for each block
mg.add_zeros('node', 'f_covered')
mg['node']['erodibility'][:] = k
spatial_step = mg.empty(centering='node')
#instantiate components
fr = Flow(mg, input_file)
lf = LakeFill(mg, input_file)
sp = Fsc(mg, input_file)
hd = Diff(mg, input_file)
tracking_mat = np.zeros((100000, 4), dtype=np.float64) #colums: 0) which node, 1) side length 2) vol 3) sub/emergence
tracking_mat[:, :] = np.nan
for_slicing = 0 #in case no blocks ever get put in
side_length = 4 #m, block side length
tau_c_br = 10 #Pa, for now
a1 = 6.5
a2 = 2.5
d = 0.1 #z0
tol = 0.01 #m water thickness error allowable
elapsed_time = 0.
keep_running = True
counter = 0 # simple incremented counter to let us see the model advance
threshold_sp = 0,
rainfall_intensity = 1)
fr = FlowRouter(mg)
lm = DepressionFinderAndRouter(mg)
expw = ExponentialWeatherer(mg,
max_soil_production_rate = maxSoilProductionRate,
soil_production_decay_depth = soilProductionDepth)
dld = DepthDependentDiffuser(mg,
linear_diffusivity = linDiff,
soil_transport_decay_depth = soilTransportDepth)
ld = LinearDiffuser(mg, linear_diffusivity = linDiff)
print("finished with the initialization of the erosion components")
print("---------------------")
##---------------------------------Main Loop------------------------------------#
t0 = time.time()
elapsed_time = 0
print("starting with main loop.")
print("---------------------")
#Create incremental counter for controlling progress of mainloop
counter = 0
#Create Limits for DHDT plot. Move this somewhere else later..
DHDTLowLim = upliftRate - (upliftRate * 1)
DHDTHighLim = upliftRate + (upliftRate * 1)
class BasicDdHy(_ErosionModel):
"""
A BasicDdHy computes erosion using 1) the hybrid alluvium component
with a threshold that varies with cumulative incision depth, the linear
diffusion component.
"""
def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""
Initialize the BasicDdHy
"""
# Call ErosionModel's init
super(BasicDdHy,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
# Get Parameters and convert units if necessary:
self.K_sp = self.get_parameter_from_exponent('K_sp')
linear_diffusivity = (
(self._length_factor**2) # L2/T
* self.get_parameter_from_exponent('linear_diffusivity'))
v_s = self.get_parameter_from_exponent('v_sc') # unitless
self.sp_crit = (
self._length_factor # L/T
* self.get_parameter_from_exponent('erosion__threshold'))
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Create a field for the (initial) erosion threshold
self.threshold = self.grid.add_zeros('node', 'erosion__threshold')
self.threshold[:] = self.sp_crit #starting value
# Handle solver option
try:
solver = self.params['solver']
except:
solver = 'original'
# Instantiate an ErosionDeposition component
self.eroder = ErosionDeposition(self.grid,
K=self.K_sp,
F_f=self.params['F_f'],
phi=self.params['phi'],
v_s=v_s,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
sp_crit='erosion__threshold',
method='threshold_stream_power',
discharge_method='drainage_area',
area_field='drainage_area',
solver=solver)
# Get the parameter for rate of threshold increase with erosion depth
self.thresh_change_per_depth = self.params['thresh_change_per_depth']
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def run_one_step(self, dt):
"""
Advance model for one time-step of duration dt.
"""
# Route flow
self.flow_router.run_one_step()
# Get IDs of flooded nodes, if any
flooded = np.where(
self.flow_router.depression_finder.flood_status == 3)[0]
# Calculate cumulative erosion and update threshold
cum_ero = self.grid.at_node['cumulative_erosion__depth']
cum_ero[:] = (self.z -
self.grid.at_node['initial_topographic__elevation'])
self.threshold[:] = (self.sp_crit -
(self.thresh_change_per_depth * cum_ero))
self.threshold[self.threshold < self.sp_crit] = self.sp_crit
# Do some erosion (but not on the flooded nodes)
# (if we're varying K through time, update that first)
if self.opt_var_precip:
self.eroder.K = (
self.K_sp *
self.pc.get_erodibility_adjustment_factor(self.model_time))
self.eroder.run_one_step(dt, flooded_nodes=flooded)
# Do some soil creep
self.diffuser.run_one_step(dt)
# calculate model time
self.model_time += dt
# Lower outlet
self.update_outlet(dt)
# Check walltime
self.check_walltime()
elev[:] = b + 0.1 * hg * np.random.rand(len(elev))
base = grid.add_zeros('node', 'aquifer_base__elevation')
wt = grid.add_zeros('node', 'water_table__elevation')
wt[:] = elev.copy()
#initialize landlab components
gdp = GroundwaterDupuitPercolator(grid, porosity=n, hydraulic_conductivity=ksat, \
regularization_f=0.01, recharge_rate=0.0, \
courant_coefficient=0.9, vn_coefficient = 0.9)
pd = PrecipitationDistribution(grid,
mean_storm_duration=tr,
mean_interstorm_duration=tb,
mean_storm_depth=ds,
total_t=Th)
pd.seed_generator(seedval=1235)
ld = LinearDiffuser(grid, linear_diffusivity=D)
#initialize other models
hm = HydrologyEventStreamPower(
grid,
precip_generator=pd,
groundwater_model=gdp,
)
#use surface_water_area_norm__discharge (Q/sqrt(A)) for Theodoratos definitions
sp = FastscapeEroder(grid,
K_sp=Ksp,
m_sp=1,
n_sp=1,
discharge_field="surface_water_area_norm__discharge")
rm = RegolithConstantThickness(grid, equilibrium_depth=b, uplift_rate=U)
class BasicRtVs(ErosionModel):
"""
A BasicVsRt computes erosion using linear diffusion, basic stream
power with 2 lithologies, and Q ~ A exp( -b S / A).
"""
def __init__(self,
input_file=None,
params=None,
BaselevelHandlerClass=None):
"""Initialize the BasicVsRt."""
# Call ErosionModel's init
super(BasicVsRt,
self).__init__(input_file=input_file,
params=params,
BaselevelHandlerClass=BaselevelHandlerClass)
contact_zone__width = (self._length_factor) * self.params[
'contact_zone__width'] # has units length
self.K_rock_sp = self.get_parameter_from_exponent('K_rock_sp')
self.K_till_sp = self.get_parameter_from_exponent('K_till_sp')
linear_diffusivity = (
self._length_factor**
2.) * self.get_parameter_from_exponent('linear_diffusivity')
recharge_rate = (self._length_factor) * self.params[
'recharge_rate'] # has units length per time
soil_thickness = (self._length_factor) * self.params[
'initial_soil_thickness'] # has units length
K_hydraulic_conductivity = (self._length_factor) * self.params[
'K_hydraulic_conductivity'] # has units length per time
# Set up rock-till
self.setup_rock_and_till(self.params['rock_till_file__name'],
self.K_rock_sp, self.K_till_sp,
contact_zone__width)
# Instantiate a FlowAccumulator with DepressionFinderAndRouter using D8 method
self.flow_router = FlowAccumulator(
self.grid,
flow_director='D8',
depression_finder=DepressionFinderAndRouter)
# Add a field for effective drainage area
if 'effective_drainage_area' in self.grid.at_node:
self.eff_area = self.grid.at_node['effective_drainage_area']
else:
self.eff_area = self.grid.add_zeros('node',
'effective_drainage_area')
# Get the effective-area parameter
self.sat_param = (K_hydraulic_conductivity * soil_thickness *
self.grid.dx) / (recharge_rate)
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerEroder(self.grid,
K_sp=self.erody,
m_sp=self.params['m_sp'],
n_sp=self.params['n_sp'],
use_Q=self.eff_area)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(self.grid,
linear_diffusivity=linear_diffusivity)
def calc_effective_drainage_area(self):
"""Calculate and store effective drainage area.
Effective drainage area is defined as:
$A_{eff} = A \exp ( \alpha S / A) = A R_r$
where $S$ is downslope-positive steepest gradient, $A$ is drainage
area, $R_r$ is the runoff ratio, and $\alpha$ is the saturation
parameter.
"""
area = self.grid.at_node['drainage_area']
slope = self.grid.at_node['topographic__steepest_slope']
cores = self.grid.core_nodes
self.eff_area[cores] = (
area[cores] *
(np.exp(-self.sat_param * slope[cores] / area[cores])))
def setup_rock_and_till(self, file_name, rock_erody, till_erody,
contact_width):
"""Set up lithology handling for two layers with different erodibility.
Parameters
----------
file_name : string
Name of arc-ascii format file containing elevation of contact
position at each grid node (or NODATA)
Read elevation of rock-till contact from an esri-ascii format file
containing the basal elevation value at each node, create a field for
erodibility.
Some considerations here:
1. We could represent the contact between two layers either as a
depth below present land surface, or as an altitude. Using a
depth would allow for vertical motion, because for a fixed
surface, the depth remains constant while the altitude changes.
But the depth must be updated every time the surface is eroded
or aggrades. Using an altitude avoids having to update the
contact position every time the surface erodes or aggrades, but
any tectonic motion would need to be applied to the contact
position as well. Here we'll use the altitude approach because
this model was originally written for an application with lots
of erosion expected but no tectonics.
"""
from landlab.io import read_esri_ascii
# Read input data on rock-till contact elevation
read_esri_ascii(file_name,
grid=self.grid,
name='rock_till_contact__elevation',
halo=1)
# Get a reference to the rock-till field
self.rock_till_contact = self.grid.at_node[
'rock_till_contact__elevation']
# Create field for erodibility
if 'substrate__erodibility' in self.grid.at_node:
self.erody = self.grid.at_node['substrate__erodibility']
else:
self.erody = self.grid.add_zeros('node', 'substrate__erodibility')
# Create array for erodibility weighting function
self.erody_wt = np.zeros(self.grid.number_of_nodes)
# Read the erodibility value of rock and till
self.rock_erody = rock_erody
self.till_erody = till_erody
# Read and remember the contact zone characteristic width
self.contact_width = contact_width
def update_erodibility_field(self):
"""Update erodibility at each node based on elevation relative to
contact elevation.
To promote smoothness in the solution, the erodibility at a given point
(x,y) is set as follows:
1. Take the difference between elevation, z(x,y), and contact
elevation, b(x,y): D(x,y) = z(x,y) - b(x,y). This number could
be positive (if land surface is above the contact), negative
(if we're well within the rock), or zero (meaning the rock-till
contact is right at the surface).
2. Define a smoothing function as:
$F(D) = 1 / (1 + exp(-D/D*))$
This sigmoidal function has the property that F(0) = 0.5,
F(D >> D*) = 1, and F(-D << -D*) = 0.
Here, D* describes the characteristic width of the "contact
zone", where the effective erodibility is a mixture of the two.
If the surface is well above this contact zone, then F = 1. If
it's well below the contact zone, then F = 0.
3. Set the erodibility using F:
$K = F K_till + (1-F) K_rock$
So, as F => 1, K => K_till, and as F => 0, K => K_rock. In
between, we have a weighted average.
Translating these symbols into variable names:
z = self.elev
b = self.rock_till_contact
D* = self.contact_width
F = self.erody_wt
K_till = self.till_erody
K_rock = self.rock_erody
"""
# Update the erodibility weighting function (this is "F")
core = self.grid.core_nodes
if self.contact_width > 0.0:
self.erody_wt[core] = (
1.0 /
(1.0 + np.exp(-(self.z[core] - self.rock_till_contact[core]) /
self.contact_width)))
else:
self.erody_wt[core] = 0.0
self.erody_wt[np.where(self.z > self.rock_till_contact)[0]] = 1.0
# (if we're varying K through time, update that first)
if self.opt_var_precip:
erode_factor = self.pc.get_erodibility_adjustment_factor(
self.model_time)
self.till_erody = self.K_till_sp * erode_factor
self.rock_erody = self.K_rock_sp * erode_factor
# Calculate the effective erodibilities using weighted averaging
self.erody[:] = (self.erody_wt * self.till_erody +
(1.0 - self.erody_wt) * self.rock_erody)
def run_one_step(self, dt):
"""
Advance model for one time-step of duration dt.
"""
# Route flow
self.flow_router.run_one_step()
# Update effective runoff ratio
self.calc_effective_drainage_area()
# Zero out effective area in flooded nodes
self.eff_area[self.flow_router.depression_finder.flood_status ==
3] = 0.0
# Update the erodibility field
self.update_erodibility_field()
# Do some erosion (but not on the flooded nodes)
self.eroder.run_one_step(dt)
# Do some soil creep
self.diffuser.run_one_step(dt)
# calculate model time
self.model_time += dt
# Lower outlet
self.update_outlet(dt)
# Check walltime
self.check_walltime()
mg = RasterModelGrid((Nr, Nc), dx)
# Initializing the elevation values
_ = mg.add_zeros('node', 'topographic__elevation')
z = np.zeros((Nr, Nc))
mg.at_node['topographic__elevation'] = z.reshape(Nr * Nc)
# Imposing fixed elevation boundary conditions
for edge in (mg.nodes_at_left_edge, mg.nodes_at_right_edge):
mg.status_at_node[edge] = FIXED_VALUE_BOUNDARY
for edge in (mg.nodes_at_bottom_edge, mg.nodes_at_top_edge):
mg.status_at_node[edge] = FIXED_VALUE_BOUNDARY
# Selecting D_infinity as the flow direction method
fc = FlowAccumulator(mg, flow_director='FlowDirectorDINF')
fd = LinearDiffuser(mg, linear_diffusivity=D)
fc.run_one_step()
# Minimum time-steps for simulation to run
min_try = 500
# Other important variables for the simulation
i = -1
t = 0
dt = 1.
diff_list = []
steady_state = False
while steady_state is False:
# Selecting 'dt' for high accuracy (user dependent)
class BasicThVs(ErosionModel):
r"""**BasicThVs** model program.
This model program combines models :py:class:`BasicTh` and
:py:class:`BasicVs`. It evolves a topographic surface described by :
math:`\eta` with the following governing equations:
.. math::
\frac{\partial \eta}{\partial t} = -\left(K A_{eff}^{m}S^{n}
- \omega_{c}\left(1-e^{-KA_{eff}^{m}S^{n}/\omega_{c}}\right)\right)
+ D\nabla^2 \eta
A_{eff} = A \exp \left( -\frac{-\alpha S}{A}\right)
\alpha = \frac{K_{sat} H dx}{R_m}
where :math:`Q` is the local stream discharge, :math:`S` is the local slope,
:math:`m` and :math:`n` are the discharge and slope exponent parameters,
:math:`K` is the erodibility by water, :math:`\omega_c` is the critical
stream power needed for erosion to occur, and :math:`D` is the regolith
transport parameter.
:math:`\alpha` is the saturation area scale used for transforming area into
effective area :math:`A_{eff}`. It is given as a function of the saturated
hydraulic conductivity :math:`K_{sat}`, the soil thickness :math:`H`, the
grid spacing :math:`dx`, and the recharge rate, :math:`R_m`.
Refer to
`Barnhart et al. (2019) <https://doi.org/10.5194/gmd-12-1267-2019>`_
Table 5 for full list of parameter symbols, names, and dimensions.
The following at-node fields must be specified in the grid:
- ``topographic__elevation``
- ``soil__depth``
"""
_required_fields = ["topographic__elevation", "soil__depth"]
def __init__(self,
clock,
grid,
m_sp=0.5,
n_sp=1.0,
water_erodibility=0.0001,
regolith_transport_parameter=0.1,
hydraulic_conductivity=0.1,
water_erosion_rule__threshold=0.01,
**kwargs):
"""
Parameters
----------
clock : terrainbento Clock instance
grid : landlab model grid instance
The grid must have all required fields.
m_sp : float, optional
Drainage area exponent (:math:`m`). Default is 0.5.
n_sp : float, optional
Slope exponent (:math:`n`). Default is 1.0.
water_erodibility : float, optional
Water erodibility (:math:`K`). Default is 0.0001.
regolith_transport_parameter : float, optional
Regolith transport efficiency (:math:`D`). Default is 0.1.
water_erosion_rule__threshold : float, optional
Erosion rule threshold when no erosion has occured
(:math:`\omega_c`). Default is 0.01.
hydraulic_conductivity : float, optional
Hydraulic conductivity (:math:`K_{sat}`). Default is 0.1.
**kwargs :
Keyword arguments to pass to :py:class:`ErosionModel`. Importantly
these arguments specify the precipitator and the runoff generator
that control the generation of surface water discharge (:math:`Q`).
Returns
-------
BasicThVs : model object
Examples
--------
This is a minimal example to demonstrate how to construct an instance
of model **BasicThVs**. For more detailed examples, including
steady-state test examples, see the terrainbento tutorials.
To begin, import the model class.
>>> from landlab import RasterModelGrid
>>> from landlab.values import random
>>> from terrainbento import Clock, BasicThVs
>>> clock = Clock(start=0, stop=100, step=1)
>>> grid = RasterModelGrid((5,5))
>>> _ = random(grid, "topographic__elevation")
>>> _ = random(grid, "soil__depth")
Construct the model.
>>> model = BasicThVs(clock, grid)
Running the model with ``model.run()`` would create output, so here we
will just run it one step.
>>> model.run_one_step(1.)
>>> model.model_time
1.0
"""
# Call ErosionModel"s init
super().__init__(clock, grid, **kwargs)
# ensure Precipitator and RunoffGenerator are vanilla
self._ensure_precip_runoff_are_vanilla(vsa_precip=True)
# verify correct fields are present.
self._verify_fields(self._required_fields)
self.m = m_sp
self.n = n_sp
self.K = water_erodibility
if float(self.n) != 1.0:
raise ValueError("Model only supports n = 1.")
# Get the effective-area parameter
self._Kdx = hydraulic_conductivity * self.grid.dx
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(
self.grid,
K_sp=self.K,
m_sp=self.m,
n_sp=self.n,
threshold_sp=water_erosion_rule__threshold,
discharge_field="surface_water__discharge",
erode_flooded_nodes=self._erode_flooded_nodes,
)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(
self.grid, linear_diffusivity=regolith_transport_parameter)
def _calc_effective_drainage_area(self):
"""Calculate and store effective drainage area."""
area = self.grid.at_node["drainage_area"]
slope = self.grid.at_node["topographic__steepest_slope"]
cores = self.grid.core_nodes
sat_param = (self._Kdx * self.grid.at_node["soil__depth"] /
self.grid.at_node["rainfall__flux"])
eff_area = area[cores] * (np.exp(
-sat_param[cores] * slope[cores] / area[cores]))
self.grid.at_node["surface_water__discharge"][cores] = eff_area
def run_one_step(self, step):
"""Advance model **BasicThVs** for one time-step of duration step.
The **run_one_step** method does the following:
1. Directs flow, accumulates drainage area, and calculates effective
drainage area.
2. Assesses the location, if any, of flooded nodes where erosion should
not occur.
3. Assesses if a :py:mod:`PrecipChanger` is an active boundary handler
and if so, uses it to modify the erodibility by water.
4. Calculates detachment-limited erosion by water.
5. Calculates topographic change by linear diffusion.
6. Finalizes the step using the :py:mod:`ErosionModel` base class
function **finalize__run_one_step**. This function updates all
boundary handlers handlers by ``step`` and increments model time by
``step``.
Parameters
----------
step : float
Increment of time for which the model is run.
"""
# create and move water
self.create_and_move_water(step)
# Update effective runoff ratio
self._calc_effective_drainage_area()
# Zero out effective area in flooded nodes
if self._erode_flooded_nodes:
flooded_nodes = []
else:
flood_status = self.grid.at_node["flood_status_code"]
flooded_nodes = np.nonzero(flood_status == _FLOODED)[0]
self.grid.at_node["surface_water__discharge"][flooded_nodes] = 0.0
# Do some erosion (but not on the flooded nodes)
# (if we're varying K through time, update that first)
if "PrecipChanger" in self.boundary_handlers:
self.eroder.K = (self.K * self.boundary_handlers["PrecipChanger"].
get_erodibility_adjustment_factor())
self.eroder.run_one_step(step)
# Do some soil creep
self.diffuser.run_one_step(step)
# Finalize the run_one_step_method
self.finalize__run_one_step(step)
# set up the input fields
zr = mg.add_zeros('node', 'topographic__elevation')
zr += mg_noise
# Landlab sets fixed elevation boundary conditions by default. This is
# what we want, so we will not modify these here.
# instantiate the components:
frr = FlowRouter(mg) # water__unit_flux_in gets automatically ingested
spr = StreamPowerEroder(mg, K_sp=K_sp, m_sp=m_sp, n_sp=n_sp, threshold_sp=0,
use_Q=None)
lake = DepressionFinderAndRouter(mg)
# Hillslopes
dfn = LinearDiffuser(mg, linear_diffusivity=K_hs)
zr_last = -9999
keep_running = np.mean(np.abs(zr - zr_last)) >= end_thresh
ti = 0
while keep_running:
zr_last = zr.copy()
zr[mg.core_nodes] += uplift_rate*dt
dfn.run_one_step(dt) # hillslopes always diffusive, even when dry
frr.run_one_step()
lake.map_depressions()
spr.run_one_step(dt, flooded_nodes=lake.lake_at_node)
keep_running = np.mean(np.abs(zr - zr_last)) >= end_thresh
ti += dt
print ti/1000., 'kyr elapsed; ', np.mean(zr-zr_last) / dt * 1E6, \
'um/yr surface uplift'
## Linear diffusion and channels on a raster
## Import what is needed
from landlab import RasterModelGrid
from landlab.components import LinearDiffuser, FlowRouter
from landlab.components import FastscapeEroder
from landlab.plot import imshow_grid
from matplotlib import pyplot as plt
## Make a grid that is 100 by 100 with dx=dy=100. m
rmg1 = RasterModelGrid((100, 100), 100.)
## Add elevation field to the grid.
z1 = rmg1.add_ones('node', 'topographic__elevation')
## Instantiate process components
ld1 = LinearDiffuser(rmg1, linear_diffusivity=0.1)
fr1 = FlowRouter(rmg1, method='D8')
fse1 = FastscapeEroder(rmg1, K_sp=1e-5, m_sp=0.5, n_sp=1.)
## Set some variables
rock_up_rate = 1e-3 #m/yr
dt = 1000 # yr
rock_up_len = dt * rock_up_rate # m
## Time loop where evolution happens
for i in range(500):
z1[rmg1.core_nodes] += rock_up_len #uplift only the core nodes
ld1.run_one_step(dt) #linear diffusion happens.
fr1.run_one_step() #flow routing happens, time step not needed
fse1.run_one_step(dt) #fluvial incision happens
## optional print statement
surface='topographic__elevation',
flow_director='D8')
lmb = LakeMapperBarnes(
grid,
method='D8',
fill_flat=False,
surface="topographic__elevation",
fill_surface="topographic__elevation",
redirect_flow_steepest_descent=False,
reaccumulate_flow=False,
track_lakes=False,
ignore_overfill=True,
)
dfr = DepressionFinderAndRouter(grid)
ld = LinearDiffuser(grid, D)
sp = FastscapeEroder(grid, K_sp=Ksp, m_sp=0.5, n_sp=1.0, threshold_sp=E0)
for i in range(N):
dfr._find_pits()
if dfr._number_of_pits > 0:
lmb.run_one_step()
z[grid.core_nodes] += U * dt
ld.run_one_step(dt)
fa.run_one_step()
sp.run_one_step(dt)
print('completed loop %d' % i)
class BasicRtVs(TwoLithologyErosionModel):
r"""**BasicRtVs** model program.
This model program combines the :py:class:`BasicRt` and :py:class:`BasicVs`
programs by allowing for two lithologies, an "upper" layer and a "lower"
layer, and using discharge proportional to effective drainage area based on
variable source area hydrology. Given a spatially varying contact zone
elevation, :math:`\eta_C(x,y))`, model **BasicRtVs** evolves a topographic
surface described by :math:`\eta` with the following governing equations:
.. math::
\frac{\partial \eta}{\partial t} = - K(\eta,\eta_C) A_{eff}^{m}S^{n}
+ D\nabla^2 \eta
K(\eta, \eta_C ) = w K_1 + (1 - w) K_2
w = \frac{1}{1+\exp \left( -\frac{(\eta -\eta_C )}{W_c}\right)}
A_{eff} = A \exp \left( -\frac{-\alpha S}{A}\right)
\alpha = \frac{K_{sat} dx }{R_m}
where :math:`Q` is the local stream discharge, :math:`S` is the local
slope, :math:`m` and :math:`n` are the discharge and slope exponent
parameters, :math:`W_c` is the contact-zone width, :math:`K_1` and
:math:`K_2` are the erodabilities of the upper and lower lithologies, and
:math:`D` is the regolith transport parameter. :math:`\alpha` is the
saturation area scale used for transforming area into effective area and it
is given as a function of the saturated hydraulic conductivity
:math:`K_{sat}`, the soil thickness :math:`H`, the grid spacing :math:`dx`,
and the recharge rate, :math:`R_m`. :math:`w` is a weight used to calculate
the effective erodibility :math:`K(\eta, \eta_C)` based on the depth to
the contact zone and the width of the contact zone.
The weight :math:`w` promotes smoothness in the solution of erodibility at
a given point. When the surface elevation is at the contact elevation, the
erodibility is the average of :math:`K_1` and :math:`K_2`; above and below
the contact, the erodibility approaches the value of :math:`K_1` and
:math:`K_2` at a rate related to the contact zone width. Thus, to make a
very sharp transition, use a small value for the contact zone width.
Refer to
`Barnhart et al. (2019) <https://doi.org/10.5194/gmd-12-1267-2019>`_
Table 5 for full list of parameter symbols, names, and dimensions.
The following at-node fields must be specified in the grid:
- ``topographic__elevation``
- ``lithology_contact__elevation``
- ``soil__depth``
"""
_required_fields = [
"topographic__elevation",
"lithology_contact__elevation",
"soil__depth",
]
def __init__(self, clock, grid, hydraulic_conductivity=0.1, **kwargs):
"""
Parameters
----------
clock : terrainbento Clock instance
grid : landlab model grid instance
The grid must have all required fields.
m_sp : float, optional
Drainage area exponent (:math:`m`). Default is 0.5.
n_sp : float, optional
Slope exponent (:math:`n`). Default is 1.0.
water_erodibility_upper : float, optional
Water erodibility of the upper layer (:math:`K_{1}`). Default is
0.001.
water_erodibility_lower : float, optional
Water erodibility of the upper layer (:math:`K_{2}`). Default is
0.0001.
contact_zone__width : float, optional
Thickness of the contact zone (:math:`W_c`). Default is 1.
regolith_transport_parameter : float, optional
Regolith transport efficiency (:math:`D`). Default is 0.1.
hydraulic_conductivity : float, optional
Hydraulic conductivity (:math:`K_{sat}`). Default is 0.1.
**kwargs :
Keyword arguments to pass to :py:class:`TwoLithologyErosionModel`.
Importantly these arguments specify the precipitator and the runoff
generator that control the generation of surface water discharge
(:math:`Q`).
Returns
-------
BasicRtVs : model object
Examples
--------
This is a minimal example to demonstrate how to construct an instance
of model **BasicRtVs**. For more detailed examples, including
steady-state test examples, see the terrainbento tutorials.
To begin, import the model class.
>>> from landlab import RasterModelGrid
>>> from landlab.values import random, constant
>>> from terrainbento import Clock, BasicRtVs
>>> clock = Clock(start=0, stop=100, step=1)
>>> grid = RasterModelGrid((5,5))
>>> _ = random(grid, "topographic__elevation")
>>> _ = random(grid, "soil__depth")
>>> _ = constant(grid, "lithology_contact__elevation", value=-10.)
Construct the model.
>>> model = BasicRtVs(clock, grid)
Running the model with ``model.run()`` would create output, so here we
will just run it one step.
>>> model.run_one_step(1.)
>>> model.model_time
1.0
"""
# Call ErosionModel"s init
super(BasicRtVs, self).__init__(clock, grid, **kwargs)
# ensure Precipitator and RunoffGenerator are vanilla
self._ensure_precip_runoff_are_vanilla()
# verify correct fields are present.
self._verify_fields(self._required_fields)
# Set up rock-till boundary and associated grid fields.
self._setup_rock_and_till()
# Get the effective-area parameter
self._Kdx = hydraulic_conductivity * self.grid.dx
# Instantiate a FastscapeEroder component
self.eroder = FastscapeEroder(
self.grid,
K_sp=self.erody,
m_sp=self.m,
n_sp=self.n,
discharge_name="surface_water__discharge",
)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(
self.grid, linear_diffusivity=self.regolith_transport_parameter
)
def _calc_effective_drainage_area(self):
r"""Calculate and store effective drainage area.
Effective drainage area is defined as:
.. math::
A_{eff} = A \exp ( \alpha S / A) = A R_r
where :math:`S` is downslope-positive steepest gradient, :math:`A` is
drainage area, :math:`R_r` is the runoff ratio, and :math:`\alpha` is
the saturation parameter.
"""
area = self.grid.at_node["drainage_area"]
slope = self.grid.at_node["topographic__steepest_slope"]
cores = self.grid.core_nodes
sat_param = (
self._Kdx
* self.grid.at_node["soil__depth"]
/ self.grid.at_node["rainfall__flux"]
)
eff_area = area[cores] * (
np.exp(-sat_param[cores] * slope[cores] / area[cores])
)
self.grid.at_node["surface_water__discharge"][cores] = eff_area
def run_one_step(self, step):
"""Advance model **BasicRtVs** for one time-step of duration step.
The **run_one_step** method does the following:
1. Directs flow, accumulates drainage area, and calculates effective
drainage area.
2. Assesses the location, if any, of flooded nodes where erosion should
not occur.
3. Assesses if a :py:mod:`PrecipChanger` is an active boundary handler
and if so, uses it to modify the erodibility by water.
4. Updates the spatially variable erodibility value based on the
relative distance between the topographic surface and the lithology
contact.
5. Calculates detachment-limited erosion by water.
6. Calculates topographic change by linear diffusion.
7. Finalizes the step using the :py:mod:`ErosionModel` base class
function **finalize__run_one_step**. This function updates all
boundary handlers handlers by ``step`` and increments model time by
``step``.
Parameters
----------
step : float
Increment of time for which the model is run.
"""
# create and move water
self.create_and_move_water(step)
# Update effective runoff ratio
self._calc_effective_drainage_area()
# Get IDs of flooded nodes, if any
if self.flow_accumulator.depression_finder is None:
flooded = []
else:
flooded = np.where(
self.flow_accumulator.depression_finder.flood_status == 3
)[0]
# Zero out effective area in flooded nodes
self.grid.at_node["surface_water__discharge"][flooded] = 0.0
# Update the erodibility field
self._update_erodibility_field()
# Do some erosion (but not on the flooded nodes)
self.eroder.run_one_step(step)
# Do some soil creep
self.diffuser.run_one_step(step)
# Finalize the run_one_step_method
self.finalize__run_one_step(step)
def __init__(self,
clock,
grid,
m_sp=0.5,
n_sp=1.0,
water_erodibility=0.0001,
regolith_transport_parameter=0.1,
hydraulic_conductivity=0.1,
water_erosion_rule__threshold=0.01,
**kwargs):
"""
Parameters
----------
clock : terrainbento Clock instance
grid : landlab model grid instance
The grid must have all required fields.
m_sp : float, optional
Drainage area exponent (:math:`m`). Default is 0.5.
n_sp : float, optional
Slope exponent (:math:`n`). Default is 1.0.
water_erodibility : float, optional
Water erodibility (:math:`K`). Default is 0.0001.
regolith_transport_parameter : float, optional
Regolith transport efficiency (:math:`D`). Default is 0.1.
water_erosion_rule__threshold : float, optional
Erosion rule threshold when no erosion has occured
(:math:`\omega_c`). Default is 0.01.
hydraulic_conductivity : float, optional
Hydraulic conductivity (:math:`K_{sat}`). Default is 0.1.
**kwargs :
Keyword arguments to pass to :py:class:`ErosionModel`. Importantly
these arguments specify the precipitator and the runoff generator
that control the generation of surface water discharge (:math:`Q`).
Returns
-------
BasicThVs : model object
Examples
--------
This is a minimal example to demonstrate how to construct an instance
of model **BasicThVs**. For more detailed examples, including
steady-state test examples, see the terrainbento tutorials.
To begin, import the model class.
>>> from landlab import RasterModelGrid
>>> from landlab.values import random
>>> from terrainbento import Clock, BasicThVs
>>> clock = Clock(start=0, stop=100, step=1)
>>> grid = RasterModelGrid((5,5))
>>> _ = random(grid, "topographic__elevation")
>>> _ = random(grid, "soil__depth")
Construct the model.
>>> model = BasicThVs(clock, grid)
Running the model with ``model.run()`` would create output, so here we
will just run it one step.
>>> model.run_one_step(1.)
>>> model.model_time
1.0
"""
# Call ErosionModel"s init
super().__init__(clock, grid, **kwargs)
# ensure Precipitator and RunoffGenerator are vanilla
self._ensure_precip_runoff_are_vanilla(vsa_precip=True)
# verify correct fields are present.
self._verify_fields(self._required_fields)
self.m = m_sp
self.n = n_sp
self.K = water_erodibility
if float(self.n) != 1.0:
raise ValueError("Model only supports n = 1.")
# Get the effective-area parameter
self._Kdx = hydraulic_conductivity * self.grid.dx
# Instantiate a FastscapeEroder component
self.eroder = StreamPowerSmoothThresholdEroder(
self.grid,
K_sp=self.K,
m_sp=self.m,
n_sp=self.n,
threshold_sp=water_erosion_rule__threshold,
discharge_field="surface_water__discharge",
erode_flooded_nodes=self._erode_flooded_nodes,
)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(
self.grid, linear_diffusivity=regolith_transport_parameter)
def __init__(self, clock, grid, hydraulic_conductivity=0.1, **kwargs):
"""
Parameters
----------
clock : terrainbento Clock instance
grid : landlab model grid instance
The grid must have all required fields.
m_sp : float, optional
Drainage area exponent (:math:`m`). Default is 0.5.
n_sp : float, optional
Slope exponent (:math:`n`). Default is 1.0.
water_erodibility_upper : float, optional
Water erodibility of the upper layer (:math:`K_{1}`). Default is
0.001.
water_erodibility_lower : float, optional
Water erodibility of the upper layer (:math:`K_{2}`). Default is
0.0001.
contact_zone__width : float, optional
Thickness of the contact zone (:math:`W_c`). Default is 1.
regolith_transport_parameter : float, optional
Regolith transport efficiency (:math:`D`). Default is 0.1.
hydraulic_conductivity : float, optional
Hydraulic conductivity (:math:`K_{sat}`). Default is 0.1.
**kwargs :
Keyword arguments to pass to :py:class:`TwoLithologyErosionModel`.
Importantly these arguments specify the precipitator and the runoff
generator that control the generation of surface water discharge
(:math:`Q`).
Returns
-------
BasicRtVs : model object
Examples
--------
This is a minimal example to demonstrate how to construct an instance
of model **BasicRtVs**. For more detailed examples, including
steady-state test examples, see the terrainbento tutorials.
To begin, import the model class.
>>> from landlab import RasterModelGrid
>>> from landlab.values import random, constant
>>> from terrainbento import Clock, BasicRtVs
>>> clock = Clock(start=0, stop=100, step=1)
>>> grid = RasterModelGrid((5,5))
>>> _ = random(grid, "topographic__elevation")
>>> _ = random(grid, "soil__depth")
>>> _ = constant(grid, "lithology_contact__elevation", value=-10.)
Construct the model.
>>> model = BasicRtVs(clock, grid)
Running the model with ``model.run()`` would create output, so here we
will just run it one step.
>>> model.run_one_step(1.)
>>> model.model_time
1.0
"""
# Call ErosionModel"s init
super(BasicRtVs, self).__init__(clock, grid, **kwargs)
# ensure Precipitator and RunoffGenerator are vanilla
self._ensure_precip_runoff_are_vanilla()
# verify correct fields are present.
self._verify_fields(self._required_fields)
# Set up rock-till boundary and associated grid fields.
self._setup_rock_and_till()
# Get the effective-area parameter
self._Kdx = hydraulic_conductivity * self.grid.dx
# Instantiate a FastscapeEroder component
self.eroder = FastscapeEroder(
self.grid,
K_sp=self.erody,
m_sp=self.m,
n_sp=self.n,
discharge_name="surface_water__discharge",
)
# Instantiate a LinearDiffuser component
self.diffuser = LinearDiffuser(
self.grid, linear_diffusivity=self.regolith_transport_parameter
)
