hydrology vs geophysics

hydrology and geophysics both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydrology	Yes	No	No	No
geophysics	Yes	No	No	No

As nouns, geophysics is a hypernym of hydrology; that is, geophysics is a word with a broader meaning than hydrology:

hydrology: the branch of geology that studies water on the earth and in the atmosphere: its distribution and uses and conservation
geophysics: geology that uses physical principles to study properties of the earth

Other hypernyms of hydrology include geophysical science.

hydrology (noun)	geophysics (noun)
the branch of geology that studies water on the earth and in the atmosphere: its distribution and uses and conservation	geology that uses physical principles to study properties of the earth