Hypsometric Map

http://www.earthexplorer.com/2009-03/Subsurface_Geology_Challenges_Goiania_Metro.asp

This is an example of a hypsomertric map used in deciding if a subway running under the city of Goiania, Brazil was possible. this is a picture of the subsurface of the ground in which the subway was to be excavated in. This image helped in the decision to not allow a subway to be constructed under the city due to soil and water issues.