linguistic geography vs dialect geography

linguistic geography and dialect geography both are nouns.

Word	Noun	Adjective	Verb	Adverb
linguistic geography	Yes	No	No	No
dialect geography	Yes	No	No	No

As nouns, linguistic geography and dialect geography are synonyms defined as:

linguistic geography and dialect geography: the study of the geographical distribution of linguistic features

linguistic geography (noun)	dialect geography (noun)
the study of the geographical distribution of linguistic features	the study of the geographical distribution of linguistic features