land area vs surface area

land area and surface area both are nouns.

Word	Noun	Adjective	Verb	Adverb
land area	Yes	No	No	No
surface area	Yes	No	No	No

As nouns, surface area is a hypernym of land area; that is, surface area is a word with a broader meaning than land area:

land area: an area of ground used for some particular purpose (such as building or farming)
surface area: the extent of a 2-dimensional surface enclosed within a boundary

Other hypernyms of land area include area, expanse.

land area (noun)	surface area (noun)
an area of ground used for some particular purpose (such as building or farming)	the extent of a 2-dimensional surface enclosed within a boundary