Source code for landlab.components.threshold_eroder.threshold_eroder

#!/usr/bin/env python3
"""Created on Wed Aug  4 11:00:08 2021.

@author: benjamincampforts
from landlab import Component, RasterModelGrid

from .cfuncs import _thresholder

[docs]class ThresholdEroder(Component): """Threshold eroder. Threshold eroder that cuts off slopes at a given threshold slope (Sc) and assumes material to dissolve away .. math:: S(S>Sc) = Sc To be coupled with :class:`~.flow_director_steepest.FlowDirectorSteepest` or :class:`~.priority_flood_flow_router.PriorityFloodFlowRouter` for the calculation of steepest slope at each timestep. Note that ThresholdEroder run_one_step() cuts off slopes and computes new elevations based on the steepest slopes as calculated by the FlowDirectorSteepest or PriorityFloodFlowRouter. If slopes over the entire model grid need be set to a threshold slope, several iterations of running the flow router and the Threshold eroder are required. Component written by Benjamin Campforts, 2022 Parameters ---------- grid : ModelGrid Landlab ModelGrid object slope_crit: float, optional Critical slope [L/L] Examples -------- >>> import numpy as np >>> from landlab import RasterModelGrid >>> from landlab.components import ThresholdEroder, PriorityFloodFlowRouter Define grid and initial topography: - 3x5 grid - east and west boundaries are open, north and south are closed - Initial topography is plane at base level on the boundaries and 1m of elevation elsewhere (core) >>> mg = RasterModelGrid((5, 5)) >>> mg.set_closed_boundaries_at_grid_edges(False, False, False, False) >>> z = np.array( ... [ ... [0., 0., 0., 0., 0.], ... [0., 1., 1., 1., 0.], ... [0., 1., 10., 1., 0.], ... [0., 1., 1., 1., 0.], ... [0., 0., 0., 0., 0.], ... ] ... ) >>> _ = mg.add_field("topographic__elevation", z, at="node") Instantiate Flow director (steepest slope type) and TL hillslope diffuser >>> fdir = PriorityFloodFlowRouter(mg) >>> th_ero = ThresholdEroder(mg, slope_crit=0.6) Run the components for ten short timepsteps >>> for t in range(2): ... fdir.run_one_step() ... th_ero.run_one_step() References ---------- **Required Software Citation(s) Specific to this Component** None Listed **Additional References** """ _name = "ThresholdEroder" _unit_agnostic = True _cite_as = """ @Article{gmd-13-3863-2020, AUTHOR = {Campforts B., Shobe C.M., Steer P., Vanmaercke M., Lague D., Braun J.}, TITLE = {BedrockLandslider 1.0: a hybrid landscape evolution model to simulate the impact of landslides and landslide-derived sediment on landscape evolution.}, JOURNAL = {Geoscientific Model Development}, VOLUME = {13}, YEAR = {2020}, NUMBER = {9}, PAGES = {3863--3886}, URL = {}, DOI = {10.5194/gmd-13-3863-2020} }""" _info = { "topographic__elevation": { "dtype": float, "intent": "inout", "optional": False, "units": "m", "mapping": "node", "doc": "Land surface topographic elevation", }, "flow__receiver_node": { "dtype": int, "intent": "in", "optional": False, "units": "-", "mapping": "node", "doc": "Node array of receivers (node that receives flow from current node)", }, "flow__upstream_node_order": { "dtype": int, "intent": "in", "optional": False, "units": "-", "mapping": "node", "doc": "Node array containing downstream-to-upstream ordered list of node IDs", }, "flow__link_to_receiver_node": { "dtype": int, "intent": "in", "optional": False, "units": "-", "mapping": "node", "doc": "ID of link downstream of each node, which carries the discharge", }, "soil__depth": { "dtype": float, "intent": "inout", "optional": True, "units": "m", "mapping": "node", "doc": "Depth of soil or weathered bedrock", }, "bedrock__elevation": { "dtype": float, "intent": "inout", "optional": True, "units": "m", "mapping": "node", "doc": "elevation of the bedrock surface", }, }
[docs] def __init__(self, grid, slope_crit=1.0): """Initialize Threshold Eroder. Parameters ---------- grid : ModelGrid Landlab ModelGrid object slope_crit: float, optional Critical slope [L/L] """ super().__init__(grid) if grid.at_node["flow__receiver_node"].size != grid.size("node"): raise NotImplementedError( "A route-to-multiple flow director has been " "run on this grid. The landlab development team has not " "verified that ThresholdEroder is compatible " "with route-to-multiple methods. Please open a GitHub Issue " "to start this process." ) # Store grid and parameters self._slope_crit = slope_crit # Link lengths depending on raster type: if isinstance(grid, RasterModelGrid): self._link_lengths = grid.length_of_d8 else: self._link_lengths = grid.length_of_link # Create fields self.initialize_output_fields() if ( "soil__depth" in self._grid.at_node and "bedrock__elevation" not in self._grid.at_node ): raise ValueError( "If soil__depth is provided as a field, " "bedrock__elevation must also be provided as a field" )
[docs] def erode(self): """Erode landscape to threshold and dissolve sediment.""" _thresholder( self.grid.at_node["flow__upstream_node_order"], self.grid.at_node["flow__link_to_receiver_node"], self._grid.at_node["flow__receiver_node"], self._link_lengths, self._grid.at_node["topographic__elevation"], self._slope_crit, ) if "soil__depth" in self._grid.at_node: self._grid.at_node["bedrock__elevation"].clip( None, self._grid.at_node["topographic__elevation"], out=self._grid.at_node["bedrock__elevation"], ) self._grid.at_node["soil__depth"][:] = ( self._grid.at_node["topographic__elevation"] - self._grid.at_node["bedrock__elevation"] )
[docs] def run_one_step(self): """Advance threshold erosion component one timestep.""" self.erode()