digging up vs human activity

digging up and human activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
digging up	Yes	No	No	No
human activity	Yes	No	No	No

As nouns, human activity is a hypernym of digging up; that is, human activity is a word with a broader meaning than digging up:

digging up: the act of digging something up out of the ground (especially a corpse) where it has been buried
human activity: something that people do or cause to happen

Other hypernyms of digging up include act, deed, human action.

digging up (noun)	human activity (noun)
the act of digging something up out of the ground (especially a corpse) where it has been buried	something that people do or cause to happen