hypsography
Concise Oxford English Dictionary © 2008 Oxford University Press:
hypsography /hɪpˈsɒgrəfi/
▶noun the study and mapping of the relative altitudes of different areas of the earth's surface.
– derivatives
hypsographic adjective,
hypsographical adjective.
hypsographic adjective,
hypsographical adjective.
'hypsography' also found in these Oxford entries:

