whitebox catchment delineation improvements

[barneydobson]

With #266 we have whitebox which introduces a range of powerful tools for catchment delineation.

A summary of obvious tasks:

• We should be able to remove all dependency on pyflwdir with this in the long run.
• Enables flexible resampling.
• Explore use of filters.
• Can more devotedly handle burning/carving in.

[barneydobson]

Example code to do this with @cheginit 's new wrapper:

import shapely

bbox = shapely.box(*dem.rio.bounds())
u, x, y = zip(
    *[
        (u, float(p["x"]), float(p["y"]))
        for u, p in g.nodes(data=True)
        if shapely.Point(p["x"], p["y"]).within(bbox)
    ]
)
gpd.GeoSeries(gpd.points_from_xy(x, y), crs=g.graph["crs"]).to_file("pour_pts.shp")

whitebox_tools("BreachDepressionsLeastCost", ["-i=dem.tif", "-o=dem_corr.tif"])
whitebox_tools("D8Pointer", ["-i=dem_corr.tif", "-o=fdir.tif"])
whitebox_tools("D8FlowAccumulation", ["-i=fdir.tif", "--pntr", "-o=streams.tif"])
whitebox_tools("JensonSnapPourPoints", ["--pour_pts=pour_pts.shp", "--streams=streams.tif", "--snap_dist=15.0", "-o=pour_pts_snapped.shp"])
whitebox_tools("Watershed", ["--d8_pntr=fdir.tif", "--pour_pts=pour_pts_snapped.shp", "-o=watersheds.tif"])

with rasterio.open("watersheds.tif") as src:
    gdf_bas = vectorize(
        src.read(1).astype(np.int32), 0, src.transform, src.crs, name="basin"
    )
    gdf_bas = gdf_bas[gdf_bas.basin != src.nodata]
    gdf_bas["id"] = [u[x - 1] for x in gdf_bas["basin"]]

[cheginit]

A more elegant way of calling whitebox_tools is using a dict:

wbt_args = {
    "BreachDepressionsLeastCost": ["-i=dem.tif", "-o=dem_corr.tif"],
    "D8Pointer": ["-i=dem_corr.tif", "-o=fdir.tif"],
    "D8FlowAccumulation": ["-i=fdir.tif", "--pntr", "-o=streams.tif"],
    "JensonSnapPourPoints": ["--pour_pts=pour_pts.shp", "--streams=streams.tif", "--snap_dist=15.0", "-o=pour_pts_snapped.shp"],
    "Watershed": ["--d8_pntr=fdir.tif", "--pour_pts=pour_pts_snapped.shp", "-o=watersheds.tif"]
}
for tool, args in wbt_args.items():
    whitebox_tools(tool, args)