Linguistic geography and geographical linguistics.
From the en.wikipedia.org
Syrians are tied together by geography, linguistic heritage, religion, and similar Eastern Mediterranean ethnicities.
From the en.wikipedia.org
His great historical and linguistic knowledge was complemented by equally deep learning in archaeology, geography and law.
From the en.wikipedia.org
We seem to be trending xenophobic, and our blessing of abundant geography seems to be connected to our linguistic provincialism.
From the economist.com
They have traditionally been classified as Malay, Para-Malay, and Aboriginal Malay, but this reflects geography and ethnicity rather than a proper linguistic classification.