I suspect non-ditch areas are classed as nodata. reclass that area to 0, then do the subtraction, otherwise you will end up with just the ditches
Les membres connectés peuvent publier, suivre les mises à jour, et plus encore. Nouveau ici ? Inscrivez-vous gratuitement.
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.