@L-K-4
Could you explain what you mean in the title of your post? I can’t see a relation with the post itself.
Concerning the Drought monitoring layers, you can see that 2 depths are considered in the soil profile, 0-40cm or 0-100cm. I don’t think that aquifers have an influence at these depths on wide scales.
Here is additional information:
https://community.windy.com/topic/18850/which-parameters-are-taken-into-account