bb_area.RdCalculates catchment area
bb_area(station_basins, germanyshape, polygon_col = "objectid")a list, each element has a vector with primary basin id from germanyshape
basin shapefile as a sf object; can be generated with bb_readgermanyshape().
name of id column in shapefile
A vector with catchment area in km2 for each list element (i.e. each catchment)