In soil surveys I've used ...
Published by Abba Niv, Drainage Engieer at Zafrir Weinstein Engineers PM
In soil surveys I've used aerial photography which can show many underground features. The best I've seen are Infra red aerial shots. Green vegetation is reddish, wet soils are dark and underground aqueducts which are near the surface can be seen by the outline of the structure . There were 2 different Infrared films,, near IR and far IR films available when I used them/