Orography: The nature of a region with respect to its elevated terrain. (Glossary of Meteorology.) Also, the study of hills and mountains.
The orography of a land mass affects winds and rainfall. Orographic clouds are created by the forced lifting of air by mountains; those clouds can produce orographic precipitation:
The extent to which winter precipitation is orographically enhanced within the Sierra Nevada of California varies from storm to storm, and season to season, from occasions when precipitation rates at low and high altitudes are almost the same to instances when precipitation rates at middle elevations ( considered here) can be as much as 30 times more than at the base of the range. (University of California, 2004.)
Watch a video depiction of orographic precipitation. (The YouTube title is misspelled, but it's correct within the video.)