xrspatial.hydro.stream_order_mfd.stream_order_mfd#

xrspatial.hydro.stream_order_mfd.stream_order_mfd(fractions: DataArray, flow_accum: DataArray, threshold: float = 100, method: str = 'strahler', name: str = 'stream_order_mfd') → DataArray[source]#

Compute stream order from MFD flow direction and accumulation grids.

Parameters:

  • fractions (xarray.DataArray or xr.Dataset) – 3-D MFD flow direction array of shape (8, H, W) as returned by flow_direction_mfd. Values are flow fractions in [0, 1] that sum to 1.0 at each cell (0.0 at pits/flats, NaN at edges or nodata cells). Supported backends: NumPy, CuPy, NumPy-backed Dask, CuPy-backed Dask. If a Dataset is passed, the operation is applied to each data variable independently.

  • flow_accum (xarray.DataArray) – 2-D flow accumulation grid. Cells with flow_accum >= threshold are considered stream cells.

  • threshold (float, default 100) – Minimum accumulation to classify a cell as part of the stream network.

  • method (str, default 'strahler') – 'strahler' for Strahler branching hierarchy or 'shreve' for Shreve cumulative magnitude.

  • name (str, default 'stream_order_mfd') – Name of output DataArray.

Returns:

2-D float64 array of stream order values. Non-stream cells (accumulation below threshold) are NaN.

Return type:

xarray.DataArray or xr.Dataset

References

Strahler, A.N. (1957). Quantitative analysis of watershed geomorphology. Transactions of the American Geophysical Union, 38(6), 913-920.

Shreve, R.L. (1966). Statistical law of stream numbers. Journal of Geology, 74(1), 17-37.