Question

Why would a portolan map be inappropriate as a resource for navigating land routes?

Answer 1

These are historical maps of coastlines, showing all the ports. don't think they would be much use to land routes.

Hope this helped!

Answer 2

Portolan maps were used in the 13th to 16th century by the European sailors. These maps were used in sailing and navigating they were characterized by loxodrome. These charts were read with the help of compass points. These charts were customarily drawn on vellum and ornamented with a frame and other details. These maps were only for navigating and sailing in the sea. So, it would have been impossible to use these maps in the land.