Columbia subject headings:
Aerial photography in geomorphology.
Aerial photography in hydrology.
Geomorphology--Canada--Remote sensing.
Hydrology--Canada--Remote sensing.
Harvard subject headings:
Aerial photography in geography.
Landforms--Canada.
Photographic interpretation.
Princeton subject headings:
Aerial photography in geomorphology.
Aerial photography in hydrology.
Geomorphology--Canada--Remote sensing.
Hydrology--Canada--Remote sensing.