change intensity vs alter

change intensity and alter both are verbs.

Word	Noun	Adjective	Verb	Adverb
change intensity	No	No	Yes	No
alter	No	No	Yes	No

As verbs, alter is a hypernym of change intensity; that is, alter is a word with a broader meaning than change intensity:

Other hypernyms of change intensity include change, modify.

change intensity (verb)	alter (verb)
increase or decrease in intensity	remove the ovaries of
	become different in some particular way, without permanently losing one's or its former characteristics or essence
	cause to change; make different; cause a transformation
	insert words into texts, often falsifying it thereby
	make an alteration to