pyflwdir 0.4.2

Fast methods to work with hydro- and topography data in pure Python.

PyFlwDir

Fast methods to work with hydro- and topography data in pure Python.

Methods include:

• flow direction upscaling

• basin delineation

• pfafstetter subbasins delineation

• upstream accumulation

• up- and downstream tracing and arithmetics

• strahler stream order

• hydrologically adjusting elevation

• height above nearest drainage

• many more!

Example

Here we show an example of a 30 arcsec D8 map of the Rhine basin which is saved in as 8-bit GeoTiff. We read the flow direction, including meta-data using rasterio to begin with.

import rasterio
with rasterio.open('data/rhine_d8.tif', 'r') as src:
    flwdir = src.read(1)
    transform = src.transform
    latlon = src.crs.to_epsg() == 4326

Next, we parse this data to a FlwdirRaster object, the core object to work with flow direction data. The most common way to initialize a FlwdirRaster object is based on gridded flow direction data in D8, LDD or NEXTXY format using the pyflwdir.from_array method. Optional arguments describe the geospatial location of the gridded data. In this step the D8 data is parsed to an actionable format.

import pyflwdir
flw = pyflwdir.from_array(flwdir, ftype='d8', transform=transform, latlon=latlon)
# When printing the FlwdirRaster instance we see its attributes.
print(flw)

Now all pyflwdir FlwdirRaster methods are available, for instance the stream_order method which returns a map with the Strahler order of each cell.

Browse the docs API for all methods

stream_order = flw.stream_order()

Getting started

Install the package from pip using

$ pip install pyflwdir

Development and Testing

See CONTRIBUTING.rst

Documentation

See docs

License

See LICENSE

Authors

See AUTHORS.txt

Changes

See CHANGESLOG.rst