| Subject | English | Latvian |
| environ. | hydrographic basin 1. The drainage basin of a stream. 2. An area occupied by a lake and its drainage basin | hidrogrāfiskais baseins |
| environ. | hydrographic network The configuration or arrangement in plan view of the natural stream courses in an area. It is related to local geologic and geomorphologic features and history. Synonym: drainage pattern | hidrogrāfiskais tīkls |
| gen. | International Hydrographic Organisation | Starptautiskā Hidrogrāfijas organizācija |