landlab.components.discharge_diffuser.diffuse_by_discharge

This is an implementation of Vaughan Voller’s experimental boundary method reduced complexity flow router. Credit: Voller, Hobley, Paola.

Created on Fri Feb 20 09:32:27 2015

@author: danhobley (SiccarPoint), after volle001@umn.edu

class DischargeDiffuser

Bases: Component

Diffuse sediment proportional to an implicit water discharge value.

This class implements Voller, Hobley, and Paola’s scheme for sediment diffusion, where the diffusivity of the sediment is proportional to the local discharge of water. The method works by solving for a potential field describing the water discharge at all nodes on the grid, which enforces both mass conservation and flow downhill along topographic gradients. This routine is designed to construct sediment fans.

Note that both the water and sediment discharges are calculated together within the component.

The algorithm uses a rule that looks like:

q_sed = q_water * (S - S_crit)

where S_crit is a critical slope threshold. [MODIFY THIS]

It is VITAL you initialize this component AFTER setting boundary conditions.

The primary method of this class is run_one_step.

Notes

This is a “research grade” component, and is subject to dramatic change with little warning. No guarantees are made regarding its accuracy or utility. It is not recommended for user use yet!

References

Required Software Citation(s) Specific to this Component

None Listed

Additional References

None Listed

Parameters:

grid (ModelGrid) – A grid.

__init__(grid, slope=0.25, flat_thresh=0.0001)

Parameters:

grid (ModelGrid) – A grid.

static __new__(cls, *args, **kwds)

cite_as = ''

property coords

Return the coordinates of nodes on grid attached to the component.

property current_time

Current time.

Some components may keep track of the current time. In this case, the current_time attribute is incremented. Otherwise it is set to None.

Return type:

current_time

definitions = (('flow__potential', "Value of the hypothetical field 'K', used to force water flux to flow downhill"), ('sediment__discharge_in', 'Sediment discharge into a node.'), ('surface_water__discharge', 'Volumetric discharge of surface water'), ('topographic__elevation', 'Land surface topographic elevation'), ('water__discharge_in', 'Incoming water discharge at node.'))

diffuse_sediment(Qw_in, Qsed_in)

property discharges_at_links

Return the discharges at links.

Note that if diagonal routing, this will return number_of_d8_links. Otherwise, it will be number_of_links.

classmethod from_path(grid, path)

Create a component from an input file.

Parameters:

• grid (ModelGrid) – A landlab grid.

• path (str or file_like) – Path to a parameter file, contents of a parameter file, or a file-like object.

Returns:

A newly-created component.

Return type:

Component

property grid

Return the grid attached to the component.

initialize_optional_output_fields()

Create fields for a component based on its optional field outputs, if declared in _optional_var_names.

This method will create new fields (without overwrite) for any fields output by the component as optional. New fields are initialized to zero. New fields are created as arrays of floats, unless the component also contains the specifying property _var_type.

initialize_output_fields(values_per_element=None)

Create fields for a component based on its input and output var names.

This method will create new fields (without overwrite) for any fields output by, but not supplied to, the component. New fields are initialized to zero. Ignores optional fields. New fields are created as arrays of floats, unless the component specifies the variable type.

Parameters:

values_per_element (int (optional)) – On occasion, it is necessary to create a field that is of size (n_grid_elements, values_per_element) instead of the default size (n_grid_elements,). Use this keyword argument to acomplish this task.

input_var_names = ('sediment__discharge_in', 'topographic__elevation', 'water__discharge_in')

name = 'DischargeDiffuser'

optional_var_names = ()

output_var_names = ('flow__potential', 'surface_water__discharge', 'topographic__elevation')

run_one_step(dt)

Run forward a duration of time, dt.

Parameters:

dt (float)

property shape

Return the grid shape attached to the component, if defined.

unit_agnostic = True

units = (('flow__potential', 'm**3/s'), ('sediment__discharge_in', 'm**3/s'), ('surface_water__discharge', 'm**3/s'), ('topographic__elevation', 'm'), ('water__discharge_in', 'm**3/s'))

classmethod var_definition(name)

Get a description of a particular field.

Parameters:

name (str) – A field name.

Returns:

A description of each field.

Return type:

tuple of (name, *description*)

classmethod var_help(name)

Print a help message for a particular field.

Parameters:

name (str) – A field name.

classmethod var_loc(name)

Location where a particular variable is defined.

Parameters:

name (str) – A field name.

Returns:

The location (‘node’, ‘link’, etc.) where a variable is defined.

Return type:

str

var_mapping = (('flow__potential', 'node'), ('sediment__discharge_in', 'node'), ('surface_water__discharge', 'node'), ('topographic__elevation', 'node'), ('water__discharge_in', 'node'))

classmethod var_type(name)

Returns the dtype of a field (float, int, bool, str…).

Parameters:

name (str) – A field name.

Returns:

The dtype of the field.

Return type:

dtype

classmethod var_units(name)

Get the units of a particular field.

Parameters:

name (str) – A field name.

Returns:

Units for the given field.

Return type:

str