pygeoprocessing.routing.helper_functions module

pygeoprocessing.routing.helper_functions.extract_streams_d8(flow_accum_raster_path_band, flow_threshold, target_stream_raster_path, raster_driver_creation_tuple=('GTIFF', ('TILED=YES', 'BIGTIFF=YES', 'COMPRESS=LZW', 'BLOCKXSIZE=256', 'BLOCKYSIZE=256')))[source]

Extract D8 streams based on a flow accumulation threshold.

Creates an unsigned byte raster where pixel values of 1 indicate the presence of a stream and pixel values of 0 indicate the absence of a stream. Any flow accumulation pixels greater than flow_threshold are considered stream pixels. Nodata values found in the input flow accumulation raster propagate through to the target stream raster.

Parameters:

  • flow_accum_raster_path_band (tuple) – A (path, band) tuple indicating the path to a D8 flow accumulation raster and the band index to use.

  • flow_threshold (number) – The flow threshold. Flow accumulation values greater than this threshold are considered stream pixels, values less than this threshold are non-stream pixels.

  • target_stream_raster_path (string) – Where the target streams raster should be written.

  • raster_driver_creation_tuple (tuple) – A tuple where the first element is the GDAL driver name of the target raster and the second element is an iterable of raster creation options for the selected driver.

Returns:

None