Compute the catchment areas of each tributary line.
The idea is to compute the route of lowest cost for any point on the glacier to rejoin a centerline. These routes are then put together if they belong to the same centerline, thus creating “catchment areas” for each centerline.
where to write the data
- Files written to the glacier directory:
A dictionary containing the shapely.Polygons of a glacier. The “polygon_hr” entry contains the geometry transformed to the local grid in (i, j) coordinates, while the “polygon_pix” entry contains the geometries transformed into the coarse grid (the i, j elements are integers). The “polygon_area” entry contains the area of the polygon as computed by Shapely. The “catchment_indices” entrycontains a list of len n_centerlines, each element containing a numpy array of the indices in the glacier grid which represent the centerlines catchment area.