RichDEM Python Reference¶
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richdem.BreachDepressions(dem, mode='Complete', fill=False, max_path_len=None, max_path_depth=None, in_place=False)¶ Attempts to breach depressions in a DEM using in-place modification.
Parameters: - dem (rdarray) – An elevation model
- mode (str) – String. Breaching mode to use (see below).
- fill (bool) – True/False. If depressions can’t be breached, should they be filled?
- max_path_len (int) – Maximum path length in cells that can be dug while breaching a depression.
- max_path_depth (float) – Maximum depth in z-units that can be dug along the breaching path.
Modes
Complete Breach everything. Ignore max_path_len, max_path_depth. There will be no depressions. There will be no mercy. Selective Only breach those depressions that can be breached using the above criteria. Constrained Dig as long a path as necessary, but don’t dig it deeper than max_path_depth. Returns: DEM with depressions breached, filled, or left unaltered, per the above options.
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richdem.FillDepressions(dem, epsilon=False, in_place=False)¶ Fills all depressions in a DEM using in-place modification.
Parameters: - dem (rdarray) – An elevation model
- epsilon (float) – If True, an epsilon gradient is imposed to all flat regions. This ensures that there is always a local gradient.
Returns: DEM without depressions.
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richdem.FlowAccumulation(dem, method=None, exponent=None)¶ Calculates flow accumulation. A variety of methods are available.
Parameters: - dem (rdarray) – An elevation model
- method (str) – Flow accumulation method to use. (See below.)
- exponent (float) – Some methods require an exponent; refer to the relevant publications for details.
Method Note Reference Tarboton Alias for Dinf. Taroboton (1997) doi: 10.1029/96WR03137 Dinf Alias for Tarboton. Taroboton (1997) doi: 10.1029/96WR03137 Quinn Holmgren with exponent=1. Quinn et al. (1991) doi: 10.1002/hyp.3360050106 Holmgren(E) Generalization of Quinn. Holmgren (1994) doi: 10.1002/hyp.3360080405 Freeman(E) TODO Freeman (1991) doi: 10.1016/0098-3004(91)90048-I FairfieldLeymarie Alias for Rho8. Fairfield and Leymarie (1991) doi: 10.1029/90WR02658 Rho8 Alias for FairfieldLeymarie. Fairfield and Leymarie (1991) doi: 10.1029/90WR02658 OCallaghan Alias for D8. O’Callaghan and Mark (1984) doi: 10.1016/S0734-189X(84)80011-0 D8 Alias for OCallaghan. O’Callaghan and Mark (1984) doi: 10.1016/S0734-189X(84)80011-0 Methods marked (E) require the exponent argument.
Returns: Flow accumulation according to the desired method.
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richdem.LoadGDAL(filename, no_data=None)¶ Read a GDAL file.
Opens any file GDAL can read, selects the first raster band, and loads it and its metadata into a RichDEM array of the appropriate data type.
If you need to do something more complicated, look at the source of this function.
Parameters: - filename (str) – Name of the raster file to open
- no_data (float) – Optionally, set the no_data value to this.
Returns: A RichDEM array
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richdem.SaveGDAL(filename, rda)¶ Save a GDAL file.
Saves a RichDEM array to a data file in GeoTIFF format.
If you need to do something more complicated, look at the source of this function.
Parameters: - filename (str) – Name of the raster file to be created
- rda (rdarray) – Data to save.
Returns: No Return
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richdem.TerrainAttribute(dem, attrib, zscale=1.0)¶ Calculates terrain attributes. A variety of methods are available.
Parameters: - dem (rdarray) – An elevation model
- attrib (str) – Terrain attribute to calculate. (See below.)
- zscale (float) – How much to scale the z-axis by prior to calculation
Method Reference slope_riserun Horn (1981) doi: 10.1109/PROC.1981.11918 slope_percentage Horn (1981) doi: 10.1109/PROC.1981.11918 slope_degrees Horn (1981) doi: 10.1109/PROC.1981.11918 slope_radians Horn (1981) doi: 10.1109/PROC.1981.11918 aspect Horn (1981) doi: 10.1109/PROC.1981.11918 curvature Zevenbergen and Thorne (1987) doi: 10.1002/esp.3290120107 planform_curvature Zevenbergen and Thorne (1987) doi: 10.1002/esp.3290120107 profile_curvature Zevenbergen and Thorne (1987) doi: 10.1002/esp.3290120107 Returns: A raster of the indicated terrain attributes.