SOTER (SO for soils, TER for terrain) is a methodology for storing and handling soils and terrain data.
SOTER uses current and emerging information technology to establish a World Soils and Terrain Database, containing digitized map units and their attribute data. The main function of this database is to provide the necessary data for improved mapping and monitoring of changes of world soil and terrain resources.
SOTER is composed of sets of files for use in a Relational DataBase Management System (RDBMS) and in a Geographic Information System (GIS).
Underlying the SOTER methodology is the identification of areas of land with a distinctive, often repetitive, pattern of landform, lithology, surface form, slope, parent material, and soil. Tracts of land distinguished in this manner are named SOTER units. Each SOTER unit thus represents one unique combination of terrain and soil characteristics.
The methodology is explained in the SOTER Procedures Manual (download PDF)