pysheds

Simple and fast watershed delineation in python.

Example usage

Read a flow direction raster
----------------------------
# Import modules
import numpy as np
import matplotlib.pyplot as plt
from pysheds.grid import Grid

# Read a grid from a raster
grid = Grid.from_raster('../data/n30w100_dir/n30w100_dir/w001001.adf',
                        data_name='dir', input_type='ascii')

Delineate a catchment
---------------------
# Specify pour point
x, y = -97.2937, 32.7371

# Delineate the catchment
grid.catchment(x, y, dirmap=(64, 128, 1, 2, 4, 8, 16, 32),
               recursionlimit=15000, xytype='label')

Crop and plot the catchment
---------------------------
# Clip the bounding box to the catchment
grid.clip_to('catch', precision=5)

# Get a view of the catchment
image_arr = np.where(grid.view('catch'), grid.view('catch'), np.nan)

# Plot the catchment
fig, ax = plt.subplots(figsize=(8,6))
plt.grid('on', zorder=1)
im = ax.imshow(image_arr, extent=grid.extent, zorder=2)
plt.colorbar(im, ax=ax)
plt.xlabel('Longitude')
plt.ylabel('Latitude')