GIS Dictionary

Definitions for GIS terms related to operations such as analysis, GIS modeling and web-based GIS, cartography, and Esri software.

Now available for purchase: A to Z GIS: An illustrated dictionary of geographic information systems.

Search the GIS Dictionary:

  Search  

Browse the GIS Dictionary:

GIS Bibliography

Researching GIS?
Search the GIS Bibliography for a vast index of books, journals, conference proceedings and reports.

tidal datum

See Also: datum, local datum, vertical geodetic datum

  1. [geodesy] A vertical datum in which zero height is defined by a particular tidal surface, often mean sea level. Examples of tidal surfaces include mean sea level, mean low water springs, and mean lower low water. Most traditional vertical geodetic datums are tidal datums.