landlab.components.hand_calculator.hand_calculator¶
Landlab component to calculate height above nearest drainage.
@author: D Litwin
- class HeightAboveDrainageCalculator[source]¶
Bases:
ComponentCalculate the elevation difference between each node and its nearest drainage node in a DEM.
This component implements the method described by Nobre et al (2011). A single direction flow director (D8 or steepest descent) must be run prior to HeightAboveDrainageCalculator to supply the flow directions. This component does not fill depressions in a DEM, but rather it treats them as drainage nodes. For best results, please run one of the available pit filling components prior to HeightAboveDrainageCalculator.
Examples
>>> import numpy as np >>> from numpy.testing import assert_equal
>>> from landlab import RasterModelGrid >>> from landlab.components import HeightAboveDrainageCalculator, FlowAccumulator
>>> mg = RasterModelGrid((4, 5)) >>> z = mg.add_zeros("topographic__elevation", at="node") >>> mg.set_status_at_node_on_edges( ... right=mg.BC_NODE_IS_CLOSED, ... bottom=mg.BC_NODE_IS_FIXED_VALUE, ... left=mg.BC_NODE_IS_CLOSED, ... top=mg.BC_NODE_IS_CLOSED, ... ) >>> elev = np.array( ... [[2, 1, 0, 1, 2], [3, 2, 1, 2, 3], [4, 3, 2, 3, 4], [5, 4, 4, 4, 5]] ... ) >>> z[:] = elev.reshape(len(z)) >>> elev array([[2, 1, 0, 1, 2], [3, 2, 1, 2, 3], [4, 3, 2, 3, 4], [5, 4, 4, 4, 5]])
>>> fa = FlowAccumulator(mg, flow_director="D8") >>> fa.run_one_step()
>>> channel__mask = mg.zeros(at="node") >>> channel__mask[[2, 7]] = 1 >>> channel__mask.reshape(elev.shape) array([[0., 0., 1., 0., 0.], [0., 0., 1., 0., 0.], [0., 0., 0., 0., 0.], [0., 0., 0., 0., 0.]])
>>> hd = HeightAboveDrainageCalculator(mg, channel_mask=channel__mask) >>> hd.run_one_step()
>>> mg.at_node["height_above_drainage__elevation"].reshape(elev.shape) array([[2., 0., 0., 0., 0.], [3., 2., 0., 2., 3.], [4., 2., 1., 2., 4.], [5., 4., 4., 4., 5.]])
References
Required Software Citation(s) Specific to this Component
None Listed
Additional References
Nobre, A. D., Cuartas, L. A., Hodnett, M., Rennó, C. D., Rodrigues, G., Silveira, A., et al. (2011). Height Above the Nearest Drainage – a hydrologically relevant new terrain model. Journal of Hydrology, 404(1), 13–29. https://doi.org/10.1016/j.jhydrol.2011.03.051
- Parameters:
grid (ModelGrid) – Landlab ModelGrid object
channel_mask (field name, array of uint8) – Logical map of nodes where drainage is present
- __init__(grid, channel_mask='channel__mask')[source]¶
- Parameters:
grid (ModelGrid) – Landlab ModelGrid object
channel_mask (field name, array of uint8) – Logical map of nodes where drainage is present
- static __new__(cls, *args, **kwds)¶
- property channel_mask¶
- 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_timeattribute is incremented. Otherwise it is set to None.- Return type:
current_time
- definitions = (('channel__mask', 'Logical map of at which grid nodes channels are present'), ('flow__receiver_node', 'Node array of receivers (node that receives flow from current node)'), ('flow__upstream_node_order', 'Node array containing downstream-to-upstream ordered list of node IDs'), ('height_above_drainage__elevation', 'Elevation above the nearest channel node'), ('topographic__elevation', 'Land surface topographic elevation'))¶
- classmethod from_path(grid, path)¶
Create a component from an input file.
- 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 = ('flow__receiver_node', 'flow__upstream_node_order', 'topographic__elevation')¶
- name = 'HeightAboveDrainageCalculator'¶
- optional_var_names = ('channel__mask',)¶
- output_var_names = ('height_above_drainage__elevation',)¶
- property shape¶
Return the grid shape attached to the component, if defined.
- unit_agnostic = True¶
- units = (('channel__mask', '-'), ('flow__receiver_node', '-'), ('flow__upstream_node_order', '-'), ('height_above_drainage__elevation', 'm'), ('topographic__elevation', 'm'))¶
- 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.
- var_mapping = (('channel__mask', 'node'), ('flow__receiver_node', 'node'), ('flow__upstream_node_order', 'node'), ('height_above_drainage__elevation', 'node'), ('topographic__elevation', 'node'))¶